WO2016039759A1

WO2016039759A1 - Additive from banana trees used for cement compositions

Info

Publication number: WO2016039759A1
Application number: PCT/US2014/055201
Authority: WO
Inventors: Deepika BUDDHIRAJU; Mayank N. PATIL
Original assignee: Halliburton Energy Services, Inc.
Priority date: 2014-09-11
Filing date: 2014-09-11
Publication date: 2016-03-17

Abstract

A cement composition for use in a well that penetrates a subterranean formation comprising: cement; water; and an additive comprising banana pseudo stem sap. A method of cementing in a subterranean formation comprising: introducing the cement composition into the subterranean formation; and allowing the cement composition to set.

Description

ADDITIVE FROM BANANA TREES USED FOR CEMENT COMPOSITIONS

Technical Field

[0001] Cement compositions can be used in a variety of oil and gas operations. Some of the properties of the cement compositions can be improved by including an additive of banana pseudo stem sap into the cement composition. The banana pseudo stem sap can be environmentally-friendly and biodegradable and can be a multi-functional additive.

Brief Description of the Figures

[0002] The features and advantages of certain

embodiments will be more readily appreciated when considered in conjunction with the accompanying figures. The figures are not to be construed as limiting any of the preferred embodiments.

[0003] Fig. 1 illustrates a system for preparation and delivery of a cement composition to a wellbore according to certain embodiments.

[0004] Fig. 2A illustrates surface equipment that may be used in placement of a cement composition into a wellbore.

[0005] Fig. 2B illustrates placement of a cement

composition into an annulus of a wellbore.

Detailed Description of the Invention

[0006] Oil and gas hydrocarbons are naturally occurring in some subterranean formations. In the oil and gas industry, a subterranean formation containing oil or gas is referred to as a reservoir. A reservoir may be located under land or off shore. Reservoirs are typically located in the range of a few hundred feet (shallow reservoirs) to a few tens of thousands of feet (ultra-deep reservoirs) . In order to produce oil or gas, a wellbore is drilled into a reservoir or adjacent to a reservoir. The oil, gas, or water produced from the wellbore is called a reservoir fluid.

[0007] A well can include, without limitation, an oil, gas, or water production well, an injection well, or a

geothermal well. As used herein, a "well" includes at least one wellbore. A wellbore can include vertical, inclined, and horizontal portions, and it can be straight, curved, or

branched. As used herein, the term "wellbore" includes any cased, and any uncased, open-hole portion of the wellbore. A near-wellbore region is the subterranean material and rock of the subterranean formation surrounding the wellbore. As used herein, a "well" also includes the near-wellbore region. The near-wellbore region is generally considered the region within approximately 100 feet radially of the wellbore. As used herein, "into a well" means and includes into any portion of the well, including into the wellbore or into the near-wellbore region via the wellbore. As used herein, "into a subterranean formation" means and includes into any portion of a subterranean formation including, into a well, wellbore, or the near-wellbore region via the wellbore.

[0008] A portion of a wellbore may be an open hole or cased hole. In an open-hole wellbore portion, a tubing string may be placed into the wellbore. The tubing string allows fluids to be introduced into or flowed from a remote portion of the wellbore. In a cased-hole wellbore portion, a casing is placed into the wellbore that can also contain a tubing string. A wellbore can contain an annulus . Examples of an annulus include, but are not limited to: the space between the wellbore and the outside of a tubing string in an open-hole wellbore; the space between the wellbore and the outside of a casing in a cased-hole wellbore; and the space between the inside of a casing and the outside of a tubing string in a cased-hole wellbore .

[0009] During well completion, it is common to introduce a cement composition into an annulus in a wellbore to form a cement sheath. As used herein, a "cement composition" is a mixture of at least cement and water. A cement composition can include additives. As used herein, the term "cement" means an initially dry substance that develops compressive strength or sets in the presence of water. An example of cement is Portland cement. A cement composition is a fluid and is generally a slurry in which the water is the external phase of the slurry and the cement (and any other insoluble particles) is the internal phase. The external phase of a cement composition can include dissolved solids.

[0010] As used herein, a "fluid" is a substance having a continuous phase that tends to flow and to conform to the outline of its container when the substance is tested at a temperature of 71 °F (22 °C) and a pressure of 1 atmosphere "atm" (0.1 megapascals "MPa") . A fluid can be a liquid or gas. A homogenous fluid has only one phase; whereas a heterogeneous fluid has more than one distinct phase. A heterogeneous fluid can be: a slurry, which includes an external liquid phase and undissolved solid particles as the internal phase; an emulsion, which includes an external liquid phase and at least one

internal phase of immiscible liquid droplets; a foam, which includes an external liquid phase and a gas as the internal phase; or a mist, which includes an external gas phase and liquid droplets as the internal phase.

[0011] By way of example, in a cased-hole wellbore, a cement composition can be placed into and allowed to set in an annulus between the wellbore and the casing in order to stabilize and secure the casing in the wellbore. By cementing the casing in the wellbore, fluids are prevented from flowing into the annulus. Consequently, oil or gas can be produced in a controlled manner by directing the flow of oil or gas through the casing and into the wellhead. Cement compositions can also be used in primary or secondary cementing operations, well- plugging, or squeeze cementing.

[0012] During cementing operations, it is necessary for the cement composition to remain pumpable during introduction into the well and until the composition is situated in the portion of the well to be cemented. After the cement

composition has reached the portion of the well to be cemented, the cement composition ultimately sets. As used herein, the term "set" and all grammatical variations thereof means the process of developing compressive strength and becoming hard or solid through curing. A cement composition that thickens too quickly while being pumped can damage pumping equipment or block tubing or pipes, and a cement composition that sets too slowly can cost time and money while waiting for the composition to set .

[0013] It is desirable for a cement composition to have certain properties, such as a desired thickening time,

compressive strength, and setting time. A variety of additives can be included in a cement composition to help obtain the certain properties.

[0014] If any laboratory test (e.g., compressive

strength) requires the step of mixing, then the cement

composition is mixed according to the following procedure. The water is added to a mixing container and the container is then placed on a mixer base. The motor of the base is then turned on and maintained at 4,000 revolutions per minute "rpm" (+/- 200 rpm) . The cement and any additives are added to the container at a uniform rate in not more than 15 seconds (s) . After all the cement and additives have been added to the water in the container, a cover is then placed on the container, and the cement composition is mixed at 12,000 rpm (+/- 500 rpm) for 35 s ( +/- 1 s) .

[0015] It is also to be understood that if any

laboratory test requires the test be performed at a specified temperature and possibly a specified pressure, then the

temperature and pressure of the cement composition is ramped up to the specified temperature and pressure after being mixed at ambient temperature and pressure. For example, the cement composition can be mixed at 71 °F (22 °C) and 1 atm (0.1 MPa) and then placed into the testing apparatus and the temperature of the cement composition can be ramped up to the specified temperature. As used herein, the rate of ramping up the

temperature is in the range of about 3 °F/min to about 5 °F/min (about 1.67 °C/min to about 2.78 °C/min) . The purpose of the specific rate of temperature ramping during measurement is to simulate the temperature profile experienced by the cement composition as it is being pumped downhole. After the cement composition is ramped up to the specified temperature and possibly specified pressure, the cement composition is

maintained at that temperature and pressure for the duration of the testing.

[0016] A cement composition can develop compressive strength. An additive can be included in a cement composition to increase its compressive strength. An additive, such as a strength-retrogression additive, can also be included to

minimize or prevent a decline of compressive strength of a cement composition over time. Certain cement compositions, such as foamed cement compositions tend to have lower compressive strengths compared to other non-foamed compositions. Being able to increase the compressive strength of foamed cement

compositions is especially important. Cement composition compressive strengths can vary from 0 psi to over 10,000 psi (0 to over 69 MPa) . Compressive strength is generally measured at a specified time after the composition has been mixed and possibly cured at a specified temperature and pressure.

Compressive strength can be measured, for example, at a time of 24 hours. Compressive strength can be measured by a destructive method or non-destructive method. The destructive method mechanically tests the compressive strength of a cement

composition. As used herein, the "destructive compressive strength" of a cement composition is measured at ambient

temperature (about 71 °F, about 22 °C) as follows. The cement composition is mixed. The cement composition is then placed into a test cell for a specified time at a specified temperature until the cement composition has set. The set cement

composition is then removed from the test cell and then placed into a compression-testing device, such as a Tinius Olsen Press, USA with fully automated hydraulics controlled by software. The pressure is gradually increased until the cement composition breaks. The destructive compressive strength is calculated as the force required to break the cement composition divided by the smallest cross-sectional area in contact with the load- bearing plates of the compression-testing device. The

destructive compressive strength is reported in units of

pressure, such as pound-force per square inch (psi) or

megapascals (MPa) .

[0017] The non-destructive compressive strength method continually measures correlated compressive strength of a cement composition sample throughout the test period by utilizing a non-destructive sonic device such as an Ultrasonic Cement Analyzer (UCA) available from FANN® Instruments in Houston, Texas. As used herein, the "non-destructive compressive

strength" of a cement composition is tested according to

ANSI/API Recommended Practice 10B-2 as follows. The cement composition is mixed. The cement composition is then placed in an Ultrasonic Cement Analyzer and tested at a specified

temperature and pressure. The UCA continually measures the transit time of the acoustic signal through the sample. The UCA device contains preset algorithms that correlate transit time to compressive strength. The UCA reports the non-destructive compressive strength of the cement composition in units of pressure, such as psi or MPa.

[0018] The compressive strength of a cement composition can be used to indicate whether the cement composition has initially set or is set. As used herein, the "initial setting time" is the difference in time between when the cement and any other ingredients are added to the water and when the

composition has reached 50 psi during the non-destructive compressive strength testing. As used herein, the "setting time" is the difference in time between when the cement and any other ingredients are added to the water and when the

composition has set at a specified temperature. It can

sometimes take up to 48 hours or longer for a cement composition to set. Some cement compositions can continue to develop compressive strength over the course of several days.

[0019] A cement set accelerator can be added to decrease the setting time and/or thickening time of a cement composition. As used herein, the "thickening time" is how long it takes for a cement composition to become unpumpable at a specified

temperature and pressure. The pumpability of a cement

composition is related to the consistency of the composition. The consistency of a cement composition is measured in Bearden units of consistency (Be) , a dimensionless unit with no direct conversion factor to the more common units of viscosity. As used herein, a cement composition becomes "unpumpable" when the consistency of the composition reaches 70 Be.

[0020] Fluids, such as water, included in a cement composition can penetrate into the surrounding subterranean formation. This is commonly referred to as fluid loss. The loss of significant amounts of fluid from the cement composition into the formation can adversely affect, inter alia, the

viscosity, thickening time, setting time, and compressive strength of the cement composition. Therefore, it is common to include a fluid loss additive in a cement composition in order to help minimize the amount of fluid that is lost from the cement composition into the subterranean formation.

[0021] As used herein, the "fluid loss" of a cement composition is tested according to the API 10B section 10, Recommended Practice for Field Testing Well Cements procedure at a specified temperature and pressure differential as follows. The cement composition is mixed. The heating jacket of the testing apparatus is preheated to approximately 6 °C (10 °F) above the specified temperature. The cement composition is stirred for 30 min. using a field mixer. The cement composition is poured into a filter cell. The testing apparatus is

assembled with a 325 mesh screen inserted into the apparatus. The cement composition is heated to the specified temperature. When the cement composition reaches the specified temperature, the lower valve stem is opened and the specified pressure differential is set. A timer is started and the filtrate out of the testing apparatus is collected in a separate volumetric container. The testing is performed for 30 min. The total volume of filtrate collected is read. Fluid loss is measured in milliliters (mL) of fluid collected in 30 min. The total mL of fluid loss is then multiplied by 2 to obtain the API fluid loss for the treatment fluid in units of mL/30 min.

[ 0022 ] A suspending agent can also be added to a cement composition to provide good suspension of the cement and/or a good sag factor. It is desirable for cement composition to have a low sedimentation value for a desired amount of time, which is indicative of good suspending properties and sag factor. As used herein, "sag factor" (SF) testing is performed according to API 10B-2 Recommended Practice for Testing Well Cements Section 15.6 as follows. The cement composition is mixed. The density of the cement composition is measured. The cement composition is then poured into a sedimentation testing tube. The cement composition is then stirred to remove any air bubbles and more cement composition is added to the tube to completely fill the tube. The tube is then sealed and can include an optional pressurization closure to prevent spillage of the composition. The sealed tube is then placed into a water-filled chamber that is pre-heated to the specified testing temperature for a

specified period of time. The tube is then removed from the chamber and allowed to cool. The set cement composition is then removed from the tube and placed in water to keep the cement from drying out. The length of the set cement is measured. The cement is then cut or broken into at least two segments

approximately 20 millimeters (mm) from the top and bottom of the cement. Each segment is then weighed to determine the specific gravity of the segment. The sag factor is calculated using the following formula: SF = SG_bottom/ (SG_bottom + SG_top) , where SG_bottom is the specific gravity of the bottom segment and SG_t0p is the specific gravity of the top segment. A sag factor of greater than 0.50 indicates that the cement composition has a potential to sag and some of the insoluble particles have settled;

therefore, a sag factor equal to 0.50 is considered to be a good sag factor and illustrates a cement composition with good suspending properties.

[0023] Another desirable property of a cement

composition is that the composition exhibit good rheology.

Rheology is a measure of how a material deforms and flows. As used herein, the "rheology" of a cement composition is measured according to API Recommended Practice 10-B2, First Edition, July 2005 as follows. The cement composition is mixed. The cement composition is placed into the test cell of a rotational viscometer, such as a FANN® Model 35 viscometer, fitted with a Bob and Sleeve attachment and a spring number 1. The cement composition is tested at the specified temperature and ambient pressure, about 1 atm (0.1 MPa) . Rheology readings are taken at multiple revolutions per minute (rpm) , for example, at 3, 6, 100, 200 and 300 rpm.

[0024] The yield point of a cement composition can indicate the resiliency of a cement composition. The yield point is the elastic limit, or the point at which a material can no longer deform elastically. When the elastic limit is exceeded by an applied stress, permanent deformation occurs. The yield point ("YP") is defined as the value obtained from the Bingham-Plastic rheological model when extrapolated to a shear rate of zero. As used herein, the "yield point" of a cement composition is calculated as the difference between the plastic viscosity and the 300 rpm dial reading, expressed in units of lb/100 sq. ft. As used herein, the "plastic viscosity" (PV) of a drilling fluid is obtained from the Bingham-Plastic

rheological model and calculated as the difference between the 300 rpm reading and the 100 rpm reading from the rheology testing x 1.5cp, expressed in units of centipoise (cP) . The higher the yield point, the more resilient a material is. [0025] The PV value can have an effect on the equivalent circulating density ("ECD") of a cement composition. ECD is the effective circulating density exerted by a fluid against the formation taking into account the flow rate and pressure drop in the annulus above the point being considered, and is measured as the difference in a cement composition' s measured surface density at the well head and the cement composition' s equivalent circulating density downhole. A low ECD is when the difference between the surface density and the equivalent circulating density downhole is relatively small. A high PV may increase the ECD due to a greater pressure drop in the annulus caused by internal fluid friction. A low PV may help minimize the amount of density increase, or equivalent circulating density caused by pumping the fluid. In addition to desiring a low PV value, it is also desirable to have a low ECD.

[0026] One particular problem with cement compositions is the presence of free fluid in the composition. Free fluid can be a result of a non-homogenous cement composition. For example, free fluid can arise from having too much liquid, such as water, or migrating gas in the cement composition or

insufficient suspending agents in the composition whereby the solids can settle out of the composition. Free fluid can comprise excess water containing dissolved solids and/or other solids from the cement composition that can float to the top of the cement composition. Free fluid typically is observed during cement hydration, but technically can occur at any time after the cement and water have been mixed together. Because the free fluid is less dense than the remaining cement composition, the free fluid tends to rise to the top of the cement composition in a container or wellbore. One of the major problems with the formation of free fluid in a cement composition is that poor or incomplete cement bonding to a tubular in a wellbore, such as a casing, can occur. This can cause a weak area in the wellbore annulus where the cement composition did not bond with the tubular .

[0027] As used herein, the amount of "free fluid" in a cement composition is performed according to API Recommended Practice 10-B2, First Edition, July 2005, Section 15.4 as follows. The cement composition is mixed. Between 100

milliliters (mL) and 250 mL of the composition is then placed into a clear graduated tube, wherein the ratio of the

composition-filled length to the inside tube diameter is greater than 6:1 and less than 8:1. The composition is then heated to the specified temperature and allowed to remain static in the tube for the specified period of time. The volume fraction, φ, of free fluid, expressed as a percent, is then calculated using the following equation:

φ = (V_F * 100)/ V_s where V_F is the volume (mL) of free fluid and V_s is the total volume (mL) of the cement composition placed into the tube.

[0028] Many countries have developed and instituted environmental regulations. Some countries now require additives to be biocompatible, environmentally friendly, and/or

biodegradable. As used herein, "biocompatible" means the quality of not having toxic or injurious effects on biological systems. For example, if the cement composition is used in off^¬ shore drilling, then a release of its additives into the water would not be harmful to aquatic life.

[0029] The OSPAR (Oslo/Paris convention for the

Protection of the Marine Environment of the North-East Atlantic) Commission has developed a pre-screening scheme for evaluating chemicals used in off-shore drilling. According to OSPAR, a chemical used in off-shore drilling should be substituted with an "environmentally-friendly" chemical if any of the following are met: a. it is on the OSPAR LCPA (List of Chemicals for

Priority Action); b. it is on the OSPAR LSPC (List of Substances of Possible Concern); c. it is on Annex XIV or XVII to REACH

(Regulation (EC) No 1907/2006 of the European Parliament and of the Council of 18 December 2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals) ; d. it is considered by the authority, to which the application has been made, to be of equivalent concern for the marine

environment as the substances covered by the previous sub^¬ paragraphs; e. it is inorganic and has a LC₅₀ or EC₅₀ less than 1 mg/1; f. it has an ultimate biodegradation (mineralization) of less than 20% in OECD 306, Marine BODIS or any other accepted marine protocols or less than 20% in 28 days in freshwater (OECD 301 and 310); g. half-life values derived from simulation tests submitted under REACH (EC 1907/2006) are greater than 60 and 180 days in marine water and sediment respectively (e.g. OECD 308, 309 conducted with marine water and sediment as appropriate); or h. it meets two of the following three criteria: (i)

biodegradation: less than 60% in 28 days (OECD 306 or any other OSPAR-accepted marine protocol) , or in the absence of valid results for such tests: less than 60% (OECD 301B, 301C, 301D, 301F, Freshwater BODIS) ; or less than 70% (OECD 301A, 301E) ;

(ii) bioaccumulation : BCF > 100 or log P_ow≥ 3 and molecular weight <700, or if the conclusion of a weight of evidence judgement under Appendix 3 of OSPAR Agreement 2008-5 is

negative; or (iii) toxicity: LCso< lOmg/1 or ECso< lOmg/1; if toxicity values <10 mg/1 are derived from limit tests to fish, actual fish LC₅₀ data should be submitted. As used herein, an additive is considered to be "environmentally friendly" if any of the above conditions are not satisfied. [0030] Biodegradability refers to tests, which allow prolonged exposure of the test substance to microorganisms. As used herein, a substance with a biodegradation rate of >20% is regarded as "inherently primary biodegradable." A substance with a biodegradation rate of >70% is regarded as "inherently ultimate biodegradable." A substance passes the

biodegradability test if the substance is regarded as either inherently primary biodegradable or inherently ultimate

biodegradable .

[0031] An additive can also be considered safe if it is a food grade product. As used herein, the term "food grade" means considered safe for use in food by the United States Food and Drug Administration (U.S. FDA) . In other words, consumption of a food grade product is considered to not cause harm to the consumer by the U.S. FDA.

[0032] Additives can also be used to prevent microbial growth, bond the cement and materials to the casing or wall of the wellbore, and control attacks from CO₂ (carbon dioxide gas) and/or H₂S (hydrogen sulfide gas) . For example, biocides can be included in a cement composition to help prevent and/or

eliminate microbial growth of additives in a cement composition. High-density additives, such as iron or manganese ore particles, can also be included in a cement composition to increase the overall density of the composition. However, these heavy, insoluble particles can settle out of the composition or provide poor bonding between the cement particles or the casing or wall of the wellbore. Therefore, a bonding agent can be included to help bond particles together and the cement composition to the casing or wellbore wall.

[0033] An acid gas well is a well containing high amounts of an acid gas, such as carbon dioxide gas, and a sour gas well is a well containing high amounts of a sour gas, such as hydrogen sulfide gas. The permeability of the cement composition can help prevent migration of an acid or sour gas through the set cement composition. Permeability refers to how easily fluids can flow through a material. For example, if the permeability is high, then fluids will flow more easily and more quickly through the material. If the permeability is low, then fluids will flow less easily and more slowly through the

material. As used herein, "high permeability" means the

material has a permeability of at least 100 millidarcy (mD) . As used herein, "low permeability" means the material has a

permeability of less than 100 mD. Therefore, it may be

desirable for the cement composition to have a low permeability to prevent migration of the gases throughout.

[0034] It may also be desirable for a cement composition to have a low heat of hydration, especially for off-shore drilling. Gas hydrates occur naturally in cold environments where the temperature and pressure are sufficient to freeze water. For example, gas hydrates occur naturally onshore in permafrost regions, and at certain depths in the sea, where water and gas combine at low temperatures and high pressures to form the hydrate. The temperature and pressure of the

surrounding environment dictates whether a gas hydrate remains stable. For example, at higher pressures, methane hydrates remain stable at temperatures up to 18 °C. However, above a certain temperature and below a certain pressure, a gas hydrate can become destabilized. As used herein, the word

"destabilized" with reference to a gas hydrate means that the gas molecules are liberated from the cage-like structure

surrounding the molecules, for example via a phase change of the water from a solid to a liquid. In this manner, the cage-like structure no longer sequesters the gas molecules and the gas molecules are free to move and behave like a gas instead of a solid. The overall heat given off during the hydration reaction of the cement with water (the heat of hydration) can vary.

Therefore, in order to maintain stable gas hydrates, it may be desirable for a cement composition to have a low heat of

hydration .

[0035] As used herein, the "heat of hydration" test of a cement composition could be performed in a standard calorimeter or can also be performed as follows. The cement composition is mixed. A known amount of the cement composition is then placed into a Thermos bottle. The mass fraction of each material by weight of the total weight of the composition tested is

determined by dividing the weight of the material used in the composition by the total weight of the composition. For

example, a cement composition made with 667 grams (g) cement, 525 g pozzolan, and 521 g water, results in mass fraction values of 0.3894 for the cement, 0.3065 for the pozzolan, and 0.3041 for the water. A thermocouple is coated with a small amount of grease so it may be removed from the set cement composition after the test is concluded. The thermocouple is inserted through a Styrofoam stopper so that the thermocouple tip will be in the center of the cement composition during testing. The Thermos bottle is sealed with the Styrofoam stopper. The

Thermos bottle is placed into an insulated curing container. The thermocouple is connected to a temperature recorder. The initial temperature of the cement composition is recorded. The temperature of the composition is continually recorded after the initial temperature has been recorded. The temperature is recorded for at least 8 hours after the maximum temperature has been reached to verify that no other chemical reactions will occur .

[0036] The "heat of hydration" of the cement composition is then calculated as follows and is expressed in units of British Thermal Units per pound (BTU/lb) . First, calculate the adiabatic temperature rise (ΔΤ) of the cement composition using the following equation, reported in units of °F:

ΔΤ = T_max - initiai Eq. 1 where T_max is the maximum recorded temperature of the cement composition and initiai is the initial recorded temperature of the cement composition. Second, calculate the heat of hydration (ΔΗ) of the cement composition according to the following equation :

ΔΗ = ΔΤ (∑XCp) Eq. 2 where ΔΤ is the calculated adiabatic temperature rise from Eq. 1 ; ∑ is the summation of the products of X and C_p for each ingredient in the cement composition; X is the mass fraction for each ingredient; and C_p is the specific heat capacity for each ingredient in units of BTU/lb * °F. The specific heat capacity for each ingredient can be found in literature or calculated using known equations. By way of example, the specific heat capacity of water is 1.000 BTU/lb * °F.

[0037] There is a need and an ongoing industry-wide concern for new and improved cement additives that can be used in a cement composition. It is highly advantageous for an additive to serve more than one function (e.g., as a set

accelerator and compressive strength enhancing additive) . This means that the overall cost of the cement composition can be decreased because fewer additives would have to be used to provide the same properties.

[0038] It has been discovered that the sap from the pseudo stem of banana plants (banana pseudo stem sap) can be used as an additive in cement compositions. Some of the

advantages of the new cement composition additive include: the sap is multi-functional; the sap is environmentally friendly, biocompatible, biodegradable, and food grade; and the cost of the cement composition can be decreased.

[0039] After banana harvesting, the pseudo stems are cut and left in fields to decay further. Banana plant pseudo stems have found various applications in medicines, the fiber industry and ink industry, dyes, textiles, adhesives etc. Different parts of the banana plant can have different applications. The pseudo stem sap of the banana plant is generally made up of 90% water and 10% of minerals, such as sodium, potassium, calcium, chlorides, sugars, lipids, resins etc. The sap was used as an antiseptic lotion on wounds in ancient days. The sap has anti^¬ bacterial and anti-fungal properties as well. India is the largest country in cultivating banana plantations with zero exports. It produces 11,000,000 metric tons of banana fields. Using the pseudo stem sap can help reduce waste after

cultivation of the bananas.

[0040] Having one single additive with multiple

applications and being 100% biodegradable is very rarely

available in the existing portfolio of chemicals used in oil and gas cementing operations. There is an on-going drive to use green chemicals to protect the environment. Moreover, this is a product from waste after harvesting a banana crop and the sap requires no further refinement for using as an additive in cement slurries.

[0041] According to an embodiment, a cement composition for use in a well that penetrates a subterranean formation comprises: cement; water; and an additive comprising banana pseudo stem sap.

[0042] According to another embodiment, a method of cementing in a subterranean formation comprises: introducing the cement composition into the subterranean formation; and allowing the cement composition to set.

[0043] It is to be understood that the discussion of preferred embodiments regarding the cement composition or any ingredient in the cement composition, is intended to apply to the composition embodiments and the method embodiments. Any reference to the unit "gallons" means U.S. gallons. As used herein, any reference to a "test cement composition" means a cement composition that consists essentially of, or consists of, the cement, the water, and the additive comprising banana pseudo stem sap and in the same proportions as the cement composition that is introduced into the subterranean formation.

[0044] The cement composition includes cement. The cement can be a hydraulic cement. A variety of hydraulic cements may be utilized including, but not limited to, those comprising calcium, aluminum, silicon, oxygen, iron, and/or sulfur, which set and harden by a reaction with water. Suitable hydraulic cements include, but are not limited to, Portland cements, gypsum cements, high alumina content cements, slag cements, high magnesia content cements, and combinations

thereof. In certain embodiments, the hydraulic cement may comprise a Portland cement. In some embodiments, the Portland cements are classified as Classes A, C, H, and G cements

according to API Specification for Materials and Testing for Well Cements, Fifth Ed., Jul. 1, 1990. Preferably, the cement is Class G or Class H cement.

[0045] The cement composition includes water. The water can be selected from the group consisting of freshwater,

brackish water, and saltwater, in any combination thereof in any proportion. The cement composition can also include a water- soluble salt. Preferably, the salt is selected from sodium chloride, calcium chloride, calcium bromide, potassium chloride, potassium bromide, magnesium chloride, and any combination thereof in any proportion. The salt can be in a concentration in the range of about 0.1% to about 40% by weight of the water.

[0046] According to an embodiment, the cement

composition has a density of at least 4 pounds per gallon "ppg" (0.5 kilograms per liter "kg/L") . The cement composition can have a density in the range of about 4 to about 24 ppg (about 0.5 to about 2.9 kg/L) . The cement composition can be a foamed cement composition. Foamed cement compositions can generally have a density in the range of about 4 to about 14 ppg (about 0.5 to about 1.7 kg/L) .

[0047] The cement composition includes an additive comprising banana pseudo stem sap. The methods can further include providing the banana pseudo stem sap. The step of providing can include obtaining the sap from a manufacturer. Alternatively, the sap can be obtained from banana plants. For example, after the banana plantation has been harvested, the pseudo stem can be collected. The stems can then be crushed to extract the juice in a similar manner as how sugar cane juice is extracted. The sap thus obtained can then be filtered and optionally stored for use as the additive. The banana pseudo stem sap can be in a concentration in the range of about 0.05 to about 5 gallons per sack of the cement (gal/sk), or about 1 to about 4 gal/sk.

[0048] According to an embodiment, the additive

comprising banana pseudo stem sap is a multi-functional additive (i.e., it provides more than one desirable property, such as thickening time and compressive strength, to the cement

composition) .

[0049] The banana pseudo stem sap is environmentally friendly, biocompatible, optionally biodegradable and food grade. As such, the sap can be used in many countries that impose environmental regulations.

[0050] The banana pseudo stem sap is an anti-fungal and anti-bacterial substance. As such, the sap does not produce bacterial growth. According to certain embodiments, the cement composition does not include a biocide. This is because a biocide is not necessary in order to consume produced bacteria because there are no bacteria produced from the banana pseudo stem sap.

[0051] The cement composition can have a good

compressive strength. The cement composition can have a nondestructive compressive strength greater than 500 psi (3 MPa) , preferably greater than 1,000 psi (7 MPa), at a temperature of 55 °F (12.8 °C) , a pressure of 3,000 psi (21 MPa), and a time of 72 hours. The cement composition can have a non-destructive compressive strength greater than 1,000 psi (7 MPa), preferably greater than 3,000 psi (21 MPa), at a temperature of 125 °F (52 °C) a pressure of 3,000 psi (21 MPa), and a time of 24 hours. The cement composition can have a destructive compressive strength greater than 500 psi (3 MPa) , preferably greater than 1,000 psi (7 MPa), at a temperature of 55 °F (12.8 °C) and a time of 72 hours. The cement composition can have a destructive compressive strength greater than 1,000 psi (7 MPa), preferably greater than 3,000 psi (21 MPa), at a temperature of 125 °F (52 °C) and a time of 24 hours. The cement composition can also have a compressive strength greater than 500 psi (3 MPa) , preferably greater than 1,000 psi (7 MPa), at the bottomhole temperature of the subterranean formation. As used herein, the term "bottomhole" means the location within the subterranean formation where the cement composition is situated. According to certain embodiments, the additive comprising banana pseudo stem sap is in at least a sufficient concentration to provide the stated compressive strengths to the cement composition. In other words, the additive comprising banana pseudo stem sap can function as a strength enhancer for the cement composition and can increase the compressive strength of the cement composition. Accordingly, the additive comprising banana pseudo stem sap can increase the compressive strength of a test cement composition compared to a substantially identical cement composition except without the additive comprising banana pseudo stem sap.

[0052] The cement composition can have a good thickening time and setting time. The cement composition can have a thickening time in the range of about 30 minutes to about 15 hours, alternatively of about 1 to about 12 hours, at a

temperature of 125 °F (52 °C) or at a temperature of 55 °F (12.8 °C) . The cement composition can have a thickening time in the range of about 30 minutes to about 15 hours, alternatively of about 1 to about 12 hours, at the bottomhole temperature and pressure of the subterranean formation. The cement composition can have a setting time of less than 48 hours, preferably less than 24 hours, at the bottomhole temperature of the subterranean formation. According to certain embodiments, the additive comprising banana pseudo stem sap is in at least a sufficient concentration to provide the stated thickening times and setting times to the cement composition. In other words, the additive comprising banana pseudo stem sap can function as a set

accelerator for the cement composition and can decrease the thickening time and the setting time of the cement composition. Accordingly, the additive comprising banana pseudo stem sap can decrease the thickening time of a test cement composition compared to a substantially identical cement composition except without the additive comprising banana pseudo stem sap. The amount of decrease in the thickening times can be a large decrease - this is especially true at lower temperatures, for example, at temperatures below 75 °F (24 °C) .

[0053] The cement composition can have a good fluid loss (i.e., a very small amount of fluid loss, if any) . The cement composition can have an API fluid loss of less than 5 mL/min, preferably less than 2 mL/min at the bottomhole temperature and pressure of the subterranean formation. According to certain embodiments, the additive comprising banana pseudo stem sap is in at least a sufficient concentration to provide the stated fluid loss to the cement composition. In other words, the additive comprising banana pseudo stem sap can function as a fluid loss control additive for the cement composition and can decrease the amount of fluid loss from the cement composition into the subterranean formation. Accordingly, the additive comprising banana pseudo stem sap can decrease the fluid loss of a test cement composition compared to a substantially identical cement composition except without the additive comprising banana pseudo stem sap. Due to good gel values and the thixotropic nature of the cement composition, complete or partial control of losses to the formation can be achieved.

[0054] The cement composition can have good suspending properties and a good sag factor. Any insoluble particles in the cement composition can remain suspended throughout the liquid external phase of the cement composition and not settle to the bottom of the column of fluid. This is confirmed by API sedimentation test. The cement composition can also have a sag factor less than or equal to 0.50. According to certain

embodiments, the additive comprising banana pseudo stem sap is in at least a sufficient concentration to provide the stated suspending properties and sag factor to the cement composition. In other words, the additive comprising banana pseudo stem sap can function as a suspending agent for the cement composition and can provide a stable cement composition. Accordingly, the additive comprising banana pseudo stem sap can provide stable test cement composition and a sag factor less than or equal to 0.50 to a test cement composition compared to a substantially identical cement composition except without the additive

comprising banana pseudo stem sap.

[0055] The cement composition can have a good yield point and low equivalent circulating density (ECD) . The cement composition can have yield point greater than about 15 lb/100 sq. ft. at a temperature of 55 °F (12.8 °C) . The cement

composition can have yield point greater than about 70 lb/100 sq. ft. at a temperature of 125 °F (52 °C) . The cement

composition can have a yield point greater than about 20 at the bottomhole temperature and pressure of the subterranean

formation. The cement composition can also have a good ECD. According to certain embodiments, the additive comprising banana pseudo stem sap is in at least a sufficient concentration to provide the stated yield point and low ECD to the cement

composition. In other words, the additive comprising banana pseudo stem sap can function as a resiliency additive for the cement composition and can increase the resiliency of the cement composition. Accordingly, the additive comprising banana pseudo stem sap can increase the yield point and resiliency and lower the ECD of a test cement composition compared to a substantially identical cement composition except without the additive

comprising banana pseudo stem sap.

[0056] The cement composition can have a low amount of free fluid. The cement composition can have a free fluid value of less than 15%, preferably less than 5%, at a temperature of 80 °F (27 °C) and a time of 2 hours. The cement composition can have a free fluid value of less than 15%, preferably less than 5%, at the bottomhole temperature and pressure of the subterranean formation after introduction into the well. According to certain embodiments, the additive comprising banana pseudo stem sap is in at least a sufficient concentration to provide the stated free fluid value to the cement composition. In other words, the additive comprising banana pseudo stem sap can function as a free fluid control agent for the cement composition and can decrease the amount of free fluid in the cement composition. Accordingly, the additive comprising banana pseudo stem sap can decrease the amount of free fluid in a test cement composition compared to a substantially identical cement composition except without the additive comprising banana pseudo stem sap.

[0057] The additive comprising banana pseudo stem sap can decrease the permeability of the cement composition. The permeability is preferably decreased such that the cement composition does not suffer from acid gases or sour gases, such as carbon dioxide gas or hydrogen sulfide gas. According to certain embodiments, the additive comprising banana pseudo stem sap is in at least a sufficient concentration to provide the desired permeability to the cement composition. Accordingly, the additive comprising banana pseudo stem sap can decrease the permeability of a test cement composition compared to a

substantially identical cement composition except without the additive comprising banana pseudo stem sap.

[0058] The additive comprising banana pseudo stem sap can also be a bonding agent. As a bonding agent, the banana pseudo stem sap can help insoluble particles bond within the cement composition to the cement and each other, as well as help the cement composition bond with wellbore casing or the wall of the wellbore.

[0059] The cement composition can have a heat of hydration (HOH) less than 50 British Thermal Units "BTU" per pound (BTU/lb), preferably less than 40 BTU/lb. According to this embodiment, the additive comprising banana pseudo stem sap can be in a concentration by weight of the cement such that the cement composition has a heat of hydration (HOH) less than 50 BTU/lb, preferably less than 40 BTU/lb. This embodiment can be useful when the cement composition is used in cold environments, such as Permafrost regions or deep off-shore drilling where gas hydrates are likely to form.

[0060] It is to be understood that while the cement composition can contain other ingredients, it is the banana pseudo stem sap that is primarily or wholly responsible for providing the stated properties, such as compressive strength and thickening time, to the cement composition. Therefore, it is not necessary for the cement composition to include other additives to achieve the desired properties. It is also to be understood that any discussion related to a "test cement

composition" is included for purposes of demonstrating that the cement composition can contain other ingredients, but it is the banana pseudo stem sap that provides the desired properties. Therefore, while it may not be possible to test the specific cement composition used in a wellbore operation in a laboratory, one can formulate a test cement composition to identify if the ingredients and concentration of the ingredients will provide the stated property (e.g., the desired compressive strength).

[0061] The cement composition can further include other additives. Examples of other additives include, but are not limited to, a filler, a friction reducer, a light-weight

additive, a foaming agent for creating a foamed composition, a high-density additive, a mechanical property enhancing additive, a lost-circulation material, a thixotropic additive, a set retarder, an inert gas for creating a foamed composition, and combinations thereof. [0062] The cement composition can include a filler.

Suitable examples of fillers include, but are not limited to, fly ash, sand, clays, and vitrified shale. The filler can be in a concentration in the range of about 5% to about 50% by weight of the cement (bwoc) .

[0063] The cement composition can include a friction reducer. Suitable examples of commercially-available friction reducers include, but are not limited to, CFR-2™, CFR-3™, CFR- 5LE™, CFR-6™, and CFR-8™, marketed by Halliburton Energy

Services, Inc. The friction reducer can be in a concentration in the range of about 0.1% to about 10% bwoc.

[0064] The cement composition can include a set

retarder. Suitable examples of commercially-available set retarders include, but are not limited to, and are marketed by Halliburton Energy Services, Inc. under the tradenames HR®-4, HR®-5, HR®-6, HR®-12, HR®-20, HR®-25, SCR-100™, and SCR-500™. The set retarder can be in a concentration in the range of about 0.05% to about 10% bwoc.

[0065] The cement composition can include a light-weight additive. Suitable examples of commercially-available light^¬ weight additives include, but are not limited to, and are marketed by Halliburton Energy Services, Inc. under the

tradenames SPHERELITE® and LUBRA-BEADS® FINE; and available from 3M in St. Paul, MN under the tradenames HGS2000™, HGS3000™, HGS4000™, HGS5000™, HGS6000™, HGS10000™, and HGS18000™ glass bubbles. The light-weight additive can be in a concentration in the range of about 5% to about 50% bwoc.

[0066] Commercially-available examples of other

additives include, but are not limited to, and are marketed by Halliburton Energy Services, Inc. under the tradenames HIGH DENSE® No. 3, HIGH DENSE® No. 4, BARITE™, and MICROMAX™, heavy- weight additives; WELLLIFE® 665, WELLLIFE ® 809, and WELLLIFE ® 810 mechanical property enhancers.

[0067] Fig. 1 illustrates a system that can be used in the preparation of a cement composition and delivery to a wellbore according to certain embodiments. As shown, the cement composition can be mixed in mixing equipment 4, such as a jet mixer, re-circulating mixer, or a batch mixer, for example, and then pumped via pumping equipment 6 to the wellbore. In some embodiments, the mixing equipment 4 and the pumping equipment 6 can be located on one or more cement trucks. In some

embodiments, a jet mixer can be used, for example, to

continuously mix the cement composition, including water, as it is being pumped to the wellbore.

[0068] An example technique and system for introducing the cement composition into a subterranean formation will now be described with reference to Figs. 2A and 2B. Fig. 2A

illustrates surface equipment 10 that can be used to introduce the cement composition. It should be noted that while Fig. 2A generally depicts a land-based operation, those skilled in the art will readily recognize that the principles described herein are equally applicable to subsea operations that employ floating or sea-based platforms and rigs, without departing from the scope of the disclosure. The surface equipment 10 can include a cementing unit 12, which can include one or more cement trucks, mixing equipment 4, and pumping equipment 6 (e.g., as depicted in Fig. 1) . The cementing unit 12 can pump the cement

composition 14 through a feed pipe 16 and to a cementing head 18, which conveys the cement composition 14 downhole.

[0069] The method embodiments include the step of introducing the cement composition into the subterranean

formation 20. Turning now to Fig. 2B, the cement composition 14 can be introduced into a subterranean formation 20. The step of introducing can include pumping the cement composition into the subterranean formation using one or more pumps 6. The step of introducing can be for the purpose of at least one of the following: well completion; foam cementing; primary or secondary cementing operations; well-plugging; squeeze cementing; and gravel packing. The cement composition can be in a pumpable state before and during introduction into the subterranean formation 20. In an embodiment, the subterranean formation 20 is penetrated by a well 22. The well can be, without

limitation, an oil, gas, or water production well, an injection well, a geothermal well, or a high-temperature and high-pressure (HTHP) well. The well can be located on land or off shore.

According to this embodiment, the step of introducing includes introducing the cement composition into the well 22. The additive comprising banana pseudo stem sap is also capable of functioning quite well in both low- and high-temperature wells. The well can have a bottomhole temperature in the range of about 50 °F to about 400 °F (about 10 °C to about 204 °C) .

[0070] The wellbore 22 comprises walls 24. A surface casing 26 can be inserted into the wellbore 22. The surface casing 26 can be cemented to the walls 24 via a cement sheath 28. One or more additional conduits (e.g., intermediate casing, production casing, liners, etc.) shown here as casing 30 can also be disposed in the wellbore 22. One or more centralizers 34 can be attached to the casing 30, for example, to centralize the casing 30 in the wellbore 22 prior to and during the

cementing operation. According to another embodiment, the subterranean formation 20 is penetrated by a wellbore 22 and the well includes an annulus 32 formed between the casing 30 and the walls 24 of the wellbore 22 and/or the surface casing 26.

According to this other embodiment, the step of introducing includes introducing the cement composition into a portion of the annulus 32.

[0071] With continued reference to Fig. 2B, the cement composition 14 can be pumped down the interior of the casing 30. The cement composition 14 can be allowed to flow down the interior of the casing 30 through the casing shoe 42 at the bottom of the casing 30 and up around the casing 30 into the annulus 32. While not illustrated, other techniques can also be utilized for introduction of the cement composition 14. By way of example, reverse circulation techniques can be used that include introducing the cement composition 14 into the

subterranean formation 20 by way of the annulus 32 instead of through the casing 30.

[0072] As it is introduced, the cement composition 14 may displace other fluids 36, such as drilling fluids and/or spacer fluids that may be present in the interior of the casing 30 and/or the annulus 32. At least a portion of the displaced fluids 36 can exit the annulus 32 via a flow line 38 and be deposited, for example, in one or more retention pits 40 (e.g., a mud pit) , as shown on Fig. 2A. Referring again to Fig. 2B, a bottom plug 44 can be introduced into the wellbore 22 ahead of the cement composition 14, for example, to separate the cement composition 14 from the fluids 36 that may be inside the casing 30 prior to cementing. After the bottom plug 44 reaches the landing collar 46, a diaphragm or other suitable device ruptures to allow the cement composition 14 through the bottom plug 44. In Fig. 2B, the bottom plug 44 is shown on the landing collar 46. In the illustrated embodiment, a top plug 48 can be

introduced into the wellbore 22 behind the cement composition 14. The top plug 48 can separate the cement composition 14 from a displacement fluid 50 and also push the cement composition 14 through the bottom plug 44. [0073] The method embodiments also include the step of allowing the cement composition to set. The step of allowing can be performed after the step of introducing the cement composition into the subterranean formation. The method

embodiments can include the additional steps of perforating, fracturing, or performing an acidizing treatment, after the step of allowing.

Examples

[0074] To facilitate a better understanding of the present invention, the following examples of certain aspects of preferred embodiments are given. The following examples are not the only examples that could be given according to the present invention and are not intended to limit the scope of the

invention .

[0075] Several cement compositions were prepared and tested according to the specific test procedure explained in the Detailed Description section above. A first set of cement compositions (Comp. #1) were prepared having a density of 15.92 pounds per gallon (ppg) (1.9 kilograms per liter "kg/L") and contained the following ingredients: Class G cement; tap water at a concentration of 43.69% by weight of the cement (bwoc) ; and varying concentrations of banana pseudo stem sap ("B-SAP") listed in units of gallons per sack of the cement (gal/sk) . A second set of cement compositions (Comp. #2) were prepared having a density of 13.5 ppg (1.62 kg/L) and contained the following ingredients: Class G cement; tap water at a

concentration of 78.67% by weight of the cement (bwoc); and varying concentrations of banana pseudo stem sap ("B-SAP") listed in units of gal/sk.

[0076] Table 1 lists the non-destructive and destructive compressive strengths of the cement compositions and the concentration of the banana pseudo stem sap (gal/sk) . The nondestructive compressive strength was performed at the listed temperatures and the listed times and a pressure of 3,000 psi (21 MPa) . The destructive compressive strength samples were cured at the listed temperature for the listed times.

Compressive strengths were reported in units of psi.

Table 1

[0077] As can be seen in Table 1, the cement

compositions containing the banana pseudo stem sap ("B-SAP") had a much higher compressive strength compared to the control compositions that did not contain the B-SAP. The 13.5 ppg control cement composition exhibited too much settling of the insoluble particles to perform compressive strength testing. However, the Comp. #2 with 1.0 gal/sk of the B-SAP had

compressive strengths exceeding 500 psi. This indicates that at both higher and lower density compositions and at higher and lower temperatures, the B-SAP functions very effectively as a compressive strength enhancer additive.

[0078] Table 2 lists the thickening time of the cement compositions and the concentration of the banana pseudo stem sap (gal/sk) . The thickening time test was performed at the listed temperatures and a pressure of 5,120 psi (35 MPa) and reported in units of hours and minutes (hr:min) . Cement Cone, of B-SAP Temp. Thickening Time

Composition (gal/sk) (°F) (hrmin)

Comp. #1- 15.9 ppg 0 125 1 :49

Comp. #1- 15.9 ppg 0.2 125 1 :39

Comp. #1- 15.9 ppg 0.5 125 1 :03

Comp. #1- 15.9 ppg 0.5 55 4:33

Comp. #2- 13.5 ppg 0 55 56:17

Comp. #2- 13.5 ppg 1.0 55 1 1 :41

Table 2

[0079] As can be seen in Table 2, the cement

compositions containing the banana pseudo stem sap ("B-SAP") had lower thickening times compared to the control compositions that did not contain the B-SAP. The low-density compositions #2 exhibited longer thickening times compared to the higher-density compositions #1. However, the addition of the B-SAP into the low-density Comp. #2, decreased the thickening time from about 56 hours down to about 12 hours. This indicates that at both higher and lower density compositions and at higher and lower temperatures, the B-SAP functions very effectively as a set accelerator .

[0080] Table 3 lists the specific gravity for the top, middle, and bottom segments of a cement composition containing the banana pseudo stem sap at a concentration of 0.5 gal/sk for the 15.92 ppg (1.91 SG) composition. The specific gravity was measured after static aging for 24hr at a temperature of 190 °F (88 °C) and a pressure of 3,000psi (20.7 MPa) in an autoclave.

Table 3 [0081] As can be seen in Table 3, there was hardly any settling in the cement composition. The cement composition also had a calculated sag factor of 0.50. This indicates that the B- SAP functions very effectively as a suspending agent.

[0082] Table 4 lists the concentration of the banana pseudo stem sap (gal/sk), rheology, yield point ("YP") listed in units of pounds per 100 square feet (lb/100 sq. ft.), and the % free fluid for Comp. #1 and Comp. #2. Rheology testing was performed at a temperature of 75 °F (24 °C) . Free fluid testing was performed at a temperature of 80 °F (27 °C) and a time of 2 hours .

Table 4

[0083] As can be seen in Table 4, both of the cement compositions exhibited good rheologies. Moreover, the YP for the 13.5 ppg cement composition was 20 lb/100 sq. ft. and 88.5 lb/100 sq. ft. for the 15.92 ppg composition. This indicates that the cement compositions had good resiliency and the B-SAP functions very effectively to provide good rheology and

elasticity to the compositions. Additionally, neither cement composition had any free fluid after 2 hours. This indicates that the B-SAP functions effectively to reduce or eliminate free fluid in a cement composition.

[0084] The exemplary fluids and additives disclosed herein may directly or indirectly affect one or more components or pieces of equipment associated with the preparation, delivery, recapture, recycling, reuse, and/or disposal of the disclosed fluids and additives. For example, the disclosed fluids and additives may directly or indirectly affect one or more mixers, related mixing equipment, mud pits, storage

facilities or units, fluid separators, heat exchangers, sensors, gauges, pumps, compressors, and the like used to generate, store, monitor, regulate, and/or recondition the exemplary fluids and additives. The disclosed fluids and additives may also directly or indirectly affect any transport or delivery equipment used to convey the fluids and additives to a well site or downhole such as, for example, any transport vessels,

conduits, pipelines, trucks, tubulars, and/or pipes used to fluidically move the fluids and additives from one location to another, any pumps, compressors, or motors (e.g., topside or downhole) used to drive the fluids and additives into motion, any valves or related joints used to regulate the pressure or flow rate of the fluids, and any sensors (i.e., pressure and temperature), gauges, and/or combinations thereof, and the like. The disclosed fluids and additives may also directly or

indirectly affect the various downhole equipment and tools that may come into contact with the fluids and additives such as, but not limited to, drill string, coiled tubing, drill pipe, drill collars, mud motors, downhole motors and/or pumps, floats,

MWD/LWD tools and related telemetry equipment, drill bits

(including roller cone, PDC, natural diamond, hole openers, reamers, and coring bits) , sensors or distributed sensors, downhole heat exchangers, valves and corresponding actuation devices, tool seals, packers and other wellbore isolation devices or components, and the like.

[0085] As used herein, the words "comprise," "have," "include," and all grammatical variations thereof are each intended to have an open, non-limiting meaning that does not exclude additional elements or steps.

[0086] Therefore, the present invention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is, therefore, evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present invention. While compositions and methods are described in terms of "comprising, " "containing," or "including" various components or steps, the compositions and methods also can "consist essentially of" or "consist of" the various components and steps. Whenever a numerical range with a lower limit and an upper limit is

disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, "from about a to about b, " or,

equivalently, "from approximately a to b, " or, equivalently, "from approximately a - b") disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles "a" or "an," as used in the claims, are defined herein to mean one or more than one of the element that it introduces. If there is any conflict in the usages of a word or term in this specification and one or more patent (s) or other documents that may be incorporated herein by reference, the definitions that are consistent with this specification should be adopted.

Claims

What is claimed is :

1. A method of cementing in a subterranean formation

comprising :

introducing a cement composition into the subterranean formation, wherein the cement composition comprises:

(A) cement;

(B) water; and

(C) an additive comprising banana pseudo stem sap; and

allowing the cement composition to set.

2. The method according to Claim 1, wherein the cement is selected from the group consisting of Portland cements, gypsum cements, high alumina content cements, slag cements, high magnesia content cements, and combinations thereof.

3. The method according to Claim 1, wherein the water is selected from the group consisting of freshwater, brackish water, and saltwater, in any combination thereof in any proportion .

4. The method according to Claim 1, wherein the cement composition further comprises a water-soluble salt, and wherein the salt is selected from sodium chloride, calcium chloride, calcium bromide, potassium chloride, potassium bromide, magnesium chloride, and any combination thereof in any

proportion .

5. The method according to Claim 1, wherein the cement composition has a density in the range of about 4 to about 24 pounds per gallon.

6. The method according to Claim 1, wherein the cement composition is a foamed cement composition.

7. The method according to Claim 1, wherein the banana pseudo stem sap is in a concentration in the range of about 0.05 to about 5 gallons per sack of the cement.

8. The method according to Claim 1, wherein the additive comprising banana pseudo stem sap is a multi-functional

additive .

9. The method according to Claim 8, wherein the additive comprising banana pseudo stem sap is at least two of the following: a compressive strength enhancer; a suspending agent; a fluid loss control agent; a bonding agent; a resiliency modifier; a permeability modifier; a free fluid control agent; or a heat of hydration modifier.

10. The method according to Claim 1, wherein the banana pseudo stem sap is environmentally friendly.

11. The method according to Claim 1, wherein the banana pseudo stem sap is biocompatible.

12. The method according to Claim 1, wherein the banana pseudo stem sap is biodegradable.

13. The method according to Claim 1, wherein the banana pseudo stem sap is food grade.

14. The method according to Claim 1, wherein the banana pseudo stem sap is an anti-fungal and anti-bacterial substance.

15. The method according to Claim 1, wherein the cement

composition has a sag factor less than or equal to 0.50.

16. The method according to Claim 1, wherein the subterranean formation is penetrated by a well, and wherein the well is an oil, gas, or water production well, an injection well, a

geothermal well, or a high-temperature and high-pressure well.

17. The method according to Claim 16, wherein the well is located off shore.

18. The method according to Claim 16, wherein the well has a bottomhole temperature in the range of about 50 °F to about 400 °F.

19. The method according to Claim 1, further comprising mixing the ingredients of the cement composition using mixing

equipment .

20. The method according to Claim 1, wherein the step of introducing comprises using one or more pumps to pump the cement composition into the subterranean formation.

21. A cement composition for use in a well that penetrates a subterranean formation comprising:

cement ;

water; and

an additive comprising banana pseudo stem sap.

22. The method according to Claim 21, wherein the banana pseudo stem sap is in a concentration in the range of about 0.05 to about 5 gallons per sack of the cement.

23. The method according to Claim 21, wherein the additive comprising banana pseudo stem sap is a multi-functional

additive .

24. The method according to Claim 23, wherein the additive comprising banana pseudo stem sap is at least two of the

following: a compressive strength enhancer; a suspending agent; a fluid loss control agent; a bonding agent; a resiliency modifier; a permeability modifier; a free fluid control agent; or a heat of hydration modifier.