[go: up one dir, main page]

CN112727438B - An annular pressure drop calculation method suitable for ultra-deep wells with long open-hole sections - Google Patents

An annular pressure drop calculation method suitable for ultra-deep wells with long open-hole sections Download PDF

Info

Publication number
CN112727438B
CN112727438B CN202110004857.0A CN202110004857A CN112727438B CN 112727438 B CN112727438 B CN 112727438B CN 202110004857 A CN202110004857 A CN 202110004857A CN 112727438 B CN112727438 B CN 112727438B
Authority
CN
China
Prior art keywords
fluid
section
formula
hole
sample point
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202110004857.0A
Other languages
Chinese (zh)
Other versions
CN112727438A (en
Inventor
曾德智
罗江
汤明
石建刚
易浩
喻智明
李双贵
蒋振兴
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Southwest Petroleum University
Original Assignee
Southwest Petroleum University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Southwest Petroleum University filed Critical Southwest Petroleum University
Priority to CN202110004857.0A priority Critical patent/CN112727438B/en
Publication of CN112727438A publication Critical patent/CN112727438A/en
Application granted granted Critical
Publication of CN112727438B publication Critical patent/CN112727438B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B47/00—Survey of boreholes or wells
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
    • E21B21/08—Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure

Landscapes

  • Engineering & Computer Science (AREA)
  • Geology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mining & Mineral Resources (AREA)
  • Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Mechanical Engineering (AREA)
  • Geophysics (AREA)
  • Earth Drilling (AREA)
  • Management, Administration, Business Operations System, And Electronic Commerce (AREA)

Abstract

本发明公开了一种适用于超深井长裸眼井段的环空压降计算方法，属于石油与天然气钻井技术领域。其特征在于：首先收集超深井钻柱资料和测井曲线数据，将不规则裸眼等效为椭圆井眼，筛选得到各样点截面，从而确定各截面环空流体过流面积和湿周长度；进一步计算等效水力直径和平均轴向流速，得到平均剪切速率，从而获取修正流性指数；进一步计算有效稠度系数、屈服值和剪切速率，从而得到有效粘度；进一步根据环空流动雷诺数计算值，得到范宁摩擦参数，最终计算出裸眼井段层流环空流动压降。本发明数值计算过程简单，能快速、准确预测不规则裸眼的环空压降，有助于超深井优快钻井参数的计算。

Figure 202110004857

The invention discloses an annular pressure drop calculation method suitable for a long open-hole section of an ultra-deep well, and belongs to the technical field of oil and natural gas drilling. It is characterized in that: firstly collect the data of the ultra-deep well drill string and the logging curve data, equate the irregular open hole as an elliptical wellbore, and obtain the cross-sections of various sample points by screening, so as to determine the annular fluid flow area and the wetted circumference length of each cross-section; Further calculate the equivalent hydraulic diameter and average axial flow velocity to obtain the average shear rate, thereby obtaining the modified fluidity index; further calculate the effective consistency coefficient, yield value and shear rate to obtain the effective viscosity; further according to the annular flow Reynolds number Calculate the value to obtain the Fanning friction parameter, and finally calculate the laminar annular flow pressure drop in the open hole section. The numerical calculation process of the invention is simple, the annular pressure drop of irregular open holes can be quickly and accurately predicted, and the calculation of optimal and fast drilling parameters of ultra-deep wells is facilitated.

Figure 202110004857

Description

Annular pressure drop calculation method suitable for long open hole section of ultra-deep well
Technical Field
The invention relates to the technical field of petroleum and natural gas drilling, in particular to an annulus pressure drop calculation method suitable for a long open hole section of an ultra-deep well.
Background
With the continuous increase of social energy demand, the development degree requirement of deep oil and gas resources with complex geological conditions and high exploitation difficulty is higher and higher, and the drilling technology of deep wells and ultra-deep wells still needs to be further perfected and developed. The calculation of the annulus pressure drop of the ultra-deep well is one of the core contents of drilling hydraulic parameter design, if the error between the calculation or prediction result and the actual annulus pressure drop is large, complex underground accidents such as well leakage, borehole wall instability, stuck drilling and the like are easily caused, and the drilling cost is increased, so that the method is necessary for meeting the practical application of engineering and quickly and accurately predicting the annulus pressure drop of the long open hole section of the ultra-deep well.
Currently, in the research of the method for calculating the annular pressure drop of the ultra-deep well, the 'method and system for predicting the bottom hole pressure' (application publication number: CN 109854237B) mainly consider the influence of the volume concentration of drill cuttings in the annular space and calculate the effective density of drilling fluid and the drilling fluid rheological parameters when the drill cuttings are contained, thereby determining the annular pressure drop and realizing the purpose of effectively predicting the bottom hole pressure; the method mainly considers the flow state of drilling fluid in the eccentric circular tube annulus power law fluid (application publication No. CN 101498214B), provides a method for calculating the Reynolds number of any gap of the cross section of the eccentric circular tube annulus, and calculates the regional angles of laminar flow and turbulent flow of the eccentric circular tube annulus. However, in the actual drilling process, the well hole is usually elliptical under the action of factors such as non-uniform ground stress, and except for elliptical well hole simulation which is difficult to apply on site, the conventional annular pressure drop calculation method usually considers a regular circular well hole, so that a certain error exists between the calculation result of the section and the underground actual annular pressure drop, and when the annular pressure drop of the elliptical well hole of the ultra-deep well is calculated, the accumulated error is larger, and the underground complex accident is more easily caused.
Disclosure of Invention
In view of the above problems, the present invention aims to provide an annulus pressure drop calculation method suitable for a long open hole section of an ultra-deep well, so as to solve the problem that the existing ultra-deep well has a large error in the calculation of the annulus pressure drop of the elliptical well under the action of factors such as non-uniform ground stress, etc., and the numerical calculation process is simple, so that the annulus pressure drop of the irregular open hole can be rapidly and accurately predicted, and the safety of drilling operation is improved.
The invention adopts the following technical scheme that the method for calculating the annular pressure drop of the long open hole section of the ultra-deep well is characterized by comprising the following steps of:
the method comprises the following steps: according to the collected ultra-deep well drill string data and the specific logging curve data, the irregular open hole is equivalent to an elliptical well hole, k sample point sections are analyzed and screened out, and the long axis length a of the open hole at the ith sample point section is determinediMinor axis length biDrill string radius ri(i ═ 1,2,3, …, k-1, k) and the annulus flow distance l between the ith and (i + 1) th sample cross-sectionsi(i＝1,2,3,…,k-1)；
Step two: the length a of the long axis of the naked eye at the section of the ith sampling point in the first stepiMinor axis length biAnd drill string radius riSubstituting formula (1) to obtain the annular fluid flow area A at the section of the ith sampling pointi；
Ai＝πaibi-πri 2(i＝1,2,3,…,k-1,k) (1)
In the formula: a. theiIs the annular fluid flow area m at the section of the ith sampling point2；aiThe length of a long axis m of a naked eye at the section of the ith sampling point; biThe minor axis length m of the naked eye at the section of the ith sampling point is shown; r isiThe radius of a drill string at the section of the ith sampling point is m;
the length a of the long axis of the naked eye at the section of the ith sampling point in the first stepiMinor axis length biAnd drill string radius riSubstituting the formula (2) to obtain the length L of the wetted perimeter at the section of the ith sampling pointi；
Li＝π(ai+bi)+2πri(i＝1,2,3,…,k-1,k) (2)
In the formula: l isiThe length m of the wetted perimeter at the section of the ith sampling point; a isiThe length of a long axis m of a naked eye at the section of the ith sampling point; biThe minor axis length m of the naked eye at the section of the ith sampling point is shown; r isiThe radius of a drill string at the section of the ith sampling point is m;
step three: the annular fluid flow area A at the section of the ith sampling point in the second stepiAnd wet circumference length LiSubstituting into formula (3) to calculate the equivalent hydraulic diameter D of the naked eyeavg；
Figure BDA0002882810670000021
In the formula: davgThe equivalent hydraulic diameter of the naked eye, m; a. theiIs the annular fluid flow area m at the section of the ith sampling point2；LiThe length m of the wetted perimeter at the section of the ith sampling point; a isiThe length of a long axis m of a naked eye at the section of the ith sampling point; biThe minor axis length m of the naked eye at the section of the ith sampling point is shown;
the annular fluid flow area A at the section of the ith sampling point in the second stepiSubstituting the formula (4) into the formula to calculate the average axial flow velocity v of the naked eyeavg；
Figure BDA0002882810670000022
In the formula: v. ofavgThe average axial flow velocity of the naked eye is m/s; a. theiIs the annular fluid flow area m at the section of the ith sampling point2(ii) a Q is the annular fluid flow, m3/s；
Step four: the equivalent hydraulic diameter D of the naked eye in the third stepavgAnd bore hole average axial flow velocity vavgSubstituting the obtained product into formula (5) to calculate the average shear rate gamma of the fluid in the open holeavg；
Figure BDA0002882810670000023
In the formula: gamma rayavgThe average shear rate of the fluid in the open hole is 1/s; davgThe equivalent hydraulic diameter of the naked eye, m; v. ofavgThe average axial flow velocity of the naked eye is m/s;
step five: averaging the shear rate gamma of the bare hole fluid in the fourth stepavgSubstituting the modified fluidity index m into a formula (6) to calculate a modified fluidity index m;
Figure BDA0002882810670000024
in the formula: m is a corrected fluidity index and is dimensionless; n is a fluidity index and is dimensionless; k is the fluid consistency coefficient, Pa · Sn；γavgThe average shear rate of the fluid in the open hole is 1/s; tau isyIs the fluid yield value, Pa;
step six: substituting the corrected fluidity index m in the step five into a formula (7) to calculate the effective fluid consistency coefficient Kef；
Figure BDA0002882810670000031
In the formula: kefIs a fluid effective consistency coefficient, Pa · Sn(ii) a K is the fluid consistency coefficient, Pa · Sn(ii) a m is a corrected fluidity index and is dimensionless;
substituting the corrected fluidity index m in the step five into a formula (8) to calculate the effective yield value tau of the fluidef；
Figure BDA0002882810670000032
In the formula: tau isefIs the fluid effective yield value, Pa; tau isyIs the fluid yield value, Pa; m is a corrected fluidity index and is dimensionless;
substituting the corrected fluidity index m in the step five into a formula (9) to calculate the effective shearing rate gamma of the fluidef；
Figure BDA0002882810670000033
In the formula: gamma rayef1/s, which is the effective shear rate of the fluid; gamma rayavgIs the average shear rate of the fluid, 1/s; m is a corrected fluidity index and is dimensionless;
step seven: the effective consistency coefficient K of the fluid in the step sixefEffective yield value of fluidefAnd effective shear rate gamma of the fluidefSubstituting into formula (10) to calculate the effective viscosity eta of the fluidef；
ηef＝τef·γef -1+Kef·γef n-1 (10)
In the formula: etaefPa/s for the effective viscosity of the fluid; kefIs a fluid effective consistency coefficient, Pa · Sn；τefIs the fluid effective yield value, Pa; gamma rayef1/s, which is the effective shear rate of the fluid; n is a fluidity index and is dimensionless;
step eight: the effective viscosity eta of the fluid in the step sevenefSubstituting the Reynolds number into the formula (11), and calculating the Reynolds number Re of the open hole annular flow;
Figure BDA0002882810670000034
in the formula: re is the Reynolds number of open hole annular flow, and is dimensionless; rho is the fluid density, kg/m3；vavgThe average axial flow velocity of the naked eye is m/s; davgThe equivalent hydraulic diameter of the naked eye, m; etaefPa/s for the effective viscosity of the fluid;
step nine: substituting the open hole annular flow Reynolds number Re in the step eight into a formula (12) to calculate a fanning friction parameter f;
Figure BDA0002882810670000035
in the formula: f is fanning friction parameter without dimension; re is the Reynolds number of annular flow, and is dimensionless;
step ten: the annular flow distance l between the section of the ith sampling point in the step one and the section of the (i + 1) th sampling pointi(i is 1,2,3, …, k-2, k-1) is substituted into the formula (14) to calculate the annular flow distance delta L, and the fanning friction parameter f in the step nine is substituted into the formula (13) to calculate the open hole laminar flow annular spaceA flow pressure drop Δ P;
Figure BDA0002882810670000041
wherein:
Figure BDA0002882810670000042
in the formula: delta P is the pressure drop of the open-hole laminar flow annulus flow, Pa; f is fanning friction parameter without dimension; v. ofavgThe average axial flow velocity of the naked eye is m/s; Δ L is the annulus flow distance, m; davgThe equivalent hydraulic diameter of the naked eye, m; liThe annulus flow distance, m, between the ith sample point cross section and the (i + 1) th sample point cross section.
Further, the value range of the annular flow distance delta L is 1-9 m.
Furthermore, the value range of the number k of the cross sections of the sampling points is 5-100.
Due to the adoption of the technical scheme, the invention has the following advantages:
(1) according to the method, the annular fluid overflowing area when the elliptical borehole changes is calculated in a segmented mode according to the ultra-deep well drill column data and the logging curve data, and the accuracy of calculation of the annular pressure drop of the ultra-deep well is improved.
(2) The method simplifies the calculation process of the annular pressure drop of the ultra-deep well by introducing a mode of correcting the fluidity index and the effective viscosity of the annular fluid.
Drawings
FIG. 1 is a flow chart of an annulus pressure drop calculation method suitable for a long open hole section of an ultra-deep well.
Detailed Description
The invention is described in detail below with reference to the drawings and the detailed description.
As shown in FIG. 1, the method for calculating the annular pressure drop suitable for the long open hole section of the ultra-deep well provided by the invention comprises the following steps:
the method comprises the following steps: according to the collected ultra-deep well drill string data and well loggingThe specific data of the curve is obtained by equating irregular open hole to elliptical borehole, analyzing and screening k sample point sections, and determining the major axis length a of the open hole at the ith sample point sectioniMinor axis length biDrill string radius ri(i ═ 1,2,3, …, k-1, k) and the annulus flow distance l between the ith and (i + 1) th sample cross-sectionsi(i＝1,2,3,…,k-1)；
Step two: the length a of the long axis of the naked eye at the section of the ith sampling point in the first stepiMinor axis length biAnd drill string radius riSubstituting formula (1) to obtain the annular fluid flow area A at the section of the ith sampling pointi；
Ai＝πaibi-πri 2(i＝1,2,3,…,k-1,k) (1)
In the formula: a. theiIs the annular fluid flow area m at the section of the ith sampling point2；aiThe length of a long axis m of a naked eye at the section of the ith sampling point; biThe minor axis length m of the naked eye at the section of the ith sampling point is shown; r isiThe radius of a drill string at the section of the ith sampling point is m;
the length a of the long axis of the naked eye at the section of the ith sampling point in the first stepiMinor axis length biAnd drill string radius riSubstituting the formula (2) to obtain the length L of the wetted perimeter at the section of the ith sampling pointi；
Li＝π(ai+bi)+2πri(i＝1,2,3,…,k-1,k) (2)
In the formula: l isiThe length m of the wetted perimeter at the section of the ith sampling point; a isiThe length of a long axis m of a naked eye at the section of the ith sampling point; biThe minor axis length m of the naked eye at the section of the ith sampling point is shown; r isiThe radius of a drill string at the section of the ith sampling point is m;
step three: the annular fluid flow area A at the section of the ith sampling point in the second stepiAnd wet circumference length LiSubstituting into formula (3) to calculate the equivalent hydraulic diameter D of the naked eyeavg；
Figure BDA0002882810670000051
In the formula: davgThe equivalent hydraulic diameter of the naked eye, m; a. theiIs the annular fluid flow area m at the section of the ith sampling point2；LiThe length m of the wetted perimeter at the section of the ith sampling point; a isiThe length of a long axis m of a naked eye at the section of the ith sampling point; biThe minor axis length m of the naked eye at the section of the ith sampling point is shown;
the annular fluid flow area A at the section of the ith sampling point in the second stepiSubstituting the formula (4) into the formula to calculate the average axial flow velocity v of the naked eyeavg；
Figure BDA0002882810670000052
In the formula: v. ofavgThe average axial flow velocity of the naked eye is m/s; a. theiIs the annular fluid flow area m at the section of the ith sampling point2(ii) a Q is the annular fluid flow, m3/s；
Step four: the equivalent hydraulic diameter D of the naked eye in the third stepavgAnd bore hole average axial flow velocity vavgSubstituting the obtained product into formula (5) to calculate the average shear rate gamma of the fluid in the open holeavg；
Figure BDA0002882810670000053
In the formula: gamma rayavgThe average shear rate of the fluid in the open hole is 1/s; davgThe equivalent hydraulic diameter of the naked eye, m; v. ofavgThe average axial flow velocity of the naked eye is m/s;
step five: averaging the shear rate gamma of the bare hole fluid in the fourth stepavgSubstituting the modified fluidity index m into a formula (6) to calculate a modified fluidity index m;
Figure BDA0002882810670000054
in the formula: m is a corrected fluidity index and is dimensionless; n is a fluidity index and is dimensionless; k is the fluid consistency coefficient, Pa · Sn；γavgThe average shear rate of the fluid in the open hole is 1/s; tau isyIs the fluid yield value, Pa;
step six: substituting the corrected fluidity index m in the step five into a formula (7) to calculate the effective fluid consistency coefficient Kef；
Figure BDA0002882810670000055
In the formula: kefIs a fluid effective consistency coefficient, Pa · Sn(ii) a K is the fluid consistency coefficient, Pa · Sn(ii) a m is a corrected fluidity index and is dimensionless;
substituting the corrected fluidity index m in the step five into a formula (8) to calculate the effective yield value tau of the fluidef；
Figure BDA0002882810670000061
In the formula: tau isefIs the fluid effective yield value, Pa; tau isyIs the fluid yield value, Pa; m is a corrected fluidity index and is dimensionless;
substituting the corrected fluidity index m in the step five into a formula (9) to calculate the effective shearing rate gamma of the fluidef；
Figure BDA0002882810670000062
In the formula: gamma rayef1/s, which is the effective shear rate of the fluid; gamma rayavgIs the average shear rate of the fluid, 1/s; m is a corrected fluidity index and is dimensionless;
step seven: the effective consistency coefficient K of the fluid in the step sixefEffective yield value of fluidefAnd effective shear rate gamma of the fluidefSubstituting into formula (10) to calculate the effective viscosity eta of the fluidef；
ηef＝τef·γef -1+Kef·γef n-1 (10)
In the formula: etaefPa/s for the effective viscosity of the fluid; kefIs a fluid effective consistency coefficient, Pa · Sn；τefIs the fluid effective yield value, Pa; gamma rayef1/s, which is the effective shear rate of the fluid; n is a fluidity index and is dimensionless;
step eight: the effective viscosity eta of the fluid in the step sevenefSubstituting the Reynolds number into the formula (11), and calculating the Reynolds number Re of the open hole annular flow;
Figure BDA0002882810670000063
in the formula: re is the Reynolds number of open hole annular flow, and is dimensionless; rho is the fluid density, kg/m3；vavgThe average axial flow velocity of the naked eye is m/s; davgThe equivalent hydraulic diameter of the naked eye, m; etaefPa/s for the effective viscosity of the fluid;
step nine: substituting the open hole annular flow Reynolds number Re in the step eight into a formula (12) to calculate a fanning friction parameter f;
Figure BDA0002882810670000064
in the formula: f is fanning friction parameter without dimension; re is the Reynolds number of annular flow, and is dimensionless;
step ten: the annular flow distance l between the section of the ith sampling point in the step one and the section of the (i + 1) th sampling pointi(i is 1,2,3, …, k-2, k-1) is substituted into the formula (14) to calculate the annular flow distance delta L, and the fanning friction parameter f in the step nine is substituted into the formula (13) to calculate the open hole laminar flow annular flow pressure drop delta P;
Figure BDA0002882810670000065
wherein:
Figure BDA0002882810670000071
in the formula: delta P is the pressure drop of the open-hole laminar flow annulus flow, Pa; f is fanning friction parameter without dimension; v. ofavgThe average axial flow velocity of the naked eye is m/s; Δ L is the annulus flow distance, m; davgThe equivalent hydraulic diameter of the naked eye, m; liThe annulus flow distance, m, between the ith sample point cross section and the (i + 1) th sample point cross section.
Further, the value range of the annular flow distance delta L is 1-9 m.
Furthermore, the value range of the number k of the cross sections of the sampling points is 5-100.
The following examples are provided to further illustrate the embodiments of the present invention and are not intended to limit the scope of the present invention.
Example (b):
an annulus pressure drop calculation method suitable for a long open hole section of an ultra-deep well comprises the following steps:
the method comprises the following steps: according to the collected ultra-deep well drill string data and the specific logging curve data, the irregular open hole is equivalent to an elliptical well hole, 5 sample point sections are analyzed and screened out, and the long axis length a of the open hole at each sample point section is determinediMinor axis length biDrill string radius ri(i ═ 1,2,3,4,5) and the annular flow distance l between the ith and the (i + 1) th spot cross-sectionsi(i ═ 1,2,3,4) in m, and the data are as follows:
(a1,b1,r1,)＝(0.112,0.093,0.070)，(a2,b2,r2)＝(0.135,0.121,0.070)，
(a3,b3,r3)＝(0.115,0.098,0.070)，(a4,b4,r4)＝(0.108,0.108,0.070)，
(a1,b1,r1)＝(0.141,0.126,0.070)，(l1,l2,l3,l4)＝(0.11,0.26,0.35,0.58)；
step two: the length a of the long axis of the naked eye at the cross section of the 5 sampling points in the step oneiMinor axis length biAnd drill string radius ri(i is 1,2,3,4,5) and substituting the formula (1) to respectively obtain the annular fluid flow area A at the section of each point1＝0.017m2，A2＝0.036m2，A3＝0.020m2，A4＝0.021m2，A5＝0.040m2，；
The length a of the long axis of the naked eye at the cross section of the 5 sampling points in the step oneiMinor axis length biAnd drill string radius ri(i is 1,2,3,4,5) and substituting the formula (2) to obtain wet circumference length L at each point section1＝1.084m，L2＝1.244m，L3＝1.109m，L4＝1.118m，L5＝1.279m；
Step three: the annular fluid flow area A at the cross section of the 5 sampling points in the step twoiAnd wet circumference length LiSubstituting (i-1, 2,3,4,5) into formula (3) to calculate the open hole equivalent hydraulic diameter Davg＝0.095m；
The annular fluid flow area A at the cross section of the 5 sampling points in the step twoi(i-1, 2,3,4,5) and a known parameter annulus fluid flow Q-0.02 m3Substituting the/s into the formula (4) to calculate the average axial flow velocity v of the naked eyeavg＝0.741m/s；
Step four: the equivalent hydraulic diameter D of the naked eye in the third stepavgAnd bore hole average axial flow velocity vavgSubstituting the obtained product into formula (5) to calculate the average shear rate gamma of the fluid in the open holeavg＝62.400 1/s；
Step five: averaging the shear rate gamma of the bare hole fluid in the fourth stepavgAnd the known parameters of fluidity index n being 0.58, fluid consistency coefficient K being 1.04 and fluid yield value tauySubstituting 10.42Pa into equation (6), and calculating the modified fluidity index m to be 0.303;
step six: substituting the corrected fluidity index m in the step five into a formula (7) to calculate the effective fluid consistency coefficient Kef＝2.756；
Substituting the corrected fluidity index m in the step five into a formula (8) to calculate the effective yield value tau of the fluidef＝27.615Pa；
Substituting the corrected fluidity index m in the step five into a formula (9) to calculate the effective shearing rate gamma of the fluidef＝165.370 1/s；
Step seven: the effective consistency coefficient K of the fluid in the step sixefEffective yield value of fluidefAnd effective shear rate gamma of the fluidefSubstituting into formula (10) to calculate the effective viscosity eta of the fluidef＝0.489Pa/s；
Step eight: the effective viscosity eta of the fluid in the step sevenefAnd the known parameter fluid density p is 1280kg/m3Substituting the equation (11) into the equation (11), and calculating an open hole annulus flow Reynolds number Re as 184.265;
step nine: substituting the open hole annular flow Reynolds number Re in the step eight into the formula (12), and calculating a fanning friction parameter f to be 0.087;
step ten: the annular flow distance l between the section of the ith sampling point in the step one and the section of the (i + 1) th sampling pointi(i is 1,2,3, …, k-2, k-1) and substituting equation (14) to calculate the annulus flow distance Δ L is 1.30m, and substituting fanning friction parameter f in the step nine into equation (13) to calculate the open hole laminar annulus flow pressure drop Δ P is 1673.460 Pa.
From the above calculations, the annulus pressure drop for an open hole annulus flow distance Δ L of 1.30m in the example was 1673.460 Pa.
The method considers the condition that the well hole is generally elliptical under the action of factors such as non-uniform ground stress and the like in the actual drilling process, adopts a method for calculating the annular fluid overflow area when the elliptical well hole is changed in a segmented mode and correcting the equivalent hydraulic diameter of the open hole, and introduces the corrected fluidity index and the effective viscosity of the annular fluid, so that the annular pressure drop calculation method suitable for the long open hole well section of the ultra-deep well is provided. The method can be used for quickly and accurately predicting the annular pressure drop of the long open hole section of the ultra-deep well based on the drill column data of the ultra-deep well, the logging curve data and the known engineering parameters, provides data support for the design of drilling hydraulic parameters, is beneficial to realizing the optimal and rapid drilling of the ultra-deep well and reduces the drilling cost.

Claims (3)

1.一种适用于超深井长裸眼井段的环空压降计算方法，其特征在于，包含以下步骤：1. an annular pressure drop calculation method that is applicable to an ultra-deep well long open hole section, is characterized in that, comprises the following steps: 步骤一：根据所收集的超深井钻柱资料和测井曲线具体数据，将不规则裸眼等效为椭圆井眼，分析筛选出k个样点截面，确定第i个样点截面处裸眼的长轴长度ai、短轴长度bi、钻柱半径ri(i＝1,2,3,…,k-1,k)和第i个样点截面与第i+1个样点截面间环空流动距离li(i＝1,2,3,…,k-1)；Step 1: According to the collected ultra-deep well drill string data and logging curve specific data, the irregular open hole is equivalent to an elliptical wellbore, and k sample cross sections are analyzed and screened, and the length of the open hole at the i-th sample point cross section is determined. Shaft length a i , short axis length b i , drill string radius ri ( i =1,2,3,...,k-1,k) and between the i-th sample point section and the i+1-th sample point section Annular flow distance li ( i =1,2,3,...,k-1); 步骤二：将步骤一中的第i个样点截面处裸眼的长轴长度ai、短轴长度bi和钻柱半径ri代入公式(1)获取第i个样点截面处环空流体过流面积Ai；Step 2: Substitute the long-axis length a i , short-axis length b i and drill string radius ri of the open hole at the cross section of the i -th sample point in step 1 into formula (1) to obtain the annular fluid at the cross-section of the i-th sample point flow area A i ; Ai＝πaibi-πri 2(i＝1,2,3,…,k-1,k) (1)A i =πa i b i -πr i 2 (i=1,2,3,...,k-1,k) (1) 式中：Ai为第i个样点截面处环空流体过流面积，m2；ai为第i个样点截面处裸眼的长轴长度，m；bi为第i个样点截面处裸眼的短轴长度，m；ri为第i个样点截面处钻柱半径，m；In the formula: A i is the annular fluid flow area at the ith sample point section, m 2 ; a i is the long axis length of the naked hole at the ith sample point section, m; b i is the ith sample point section The short-axis length of the open hole at the location, m; ri is the drill string radius at the section of the i -th sample point, m; 将步骤一中的第i个样点截面处裸眼的长轴长度ai、短轴长度bi和钻柱半径ri代入公式(2)获取第i个样点截面处湿周长度Li；Substitute the long-axis length a i , the short-axis length b i and the drill string radius ri of the open hole at the ith sample point section in step 1 into formula (2) to obtain the wet circumference length Li at the ith sample point section; Li＝π(ai+bi)+2πri(i＝1,2,3,…,k-1,k) (2)L i =π(a i +b i )+2πr i (i=1,2,3,...,k-1,k) (2) 式中：Li为第i个样点截面处湿周长度，m；ai为第i个样点截面处裸眼的长轴长度，m；bi为第i个样点截面处裸眼的短轴长度，m；ri为第i个样点截面处钻柱半径，m；In the formula: Li is the wet circumference length at the section of the ith sample point, m; a i is the long axis length of the naked eye at the section of the ith sample point, m; b i is the short length of the naked eye at the section of the ith sample point. Shaft length, m; ri is the drill string radius at the i -th sample point section, m; 步骤三：将步骤二中的第i个样点截面处环空流体过流面积Ai和湿周长度Li代入公式(3)中，计算出裸眼等效水力直径Davg；Step 3: Substitute the annular fluid flow area A i and the wet circumference length Li at the cross section of the i -th sample point in the step 2 into formula (3), and calculate the naked-hole equivalent hydraulic diameter D avg ;
Figure FDA0002882810660000011
Figure FDA0002882810660000011
 式中：Davg为裸眼等效水力直径，m；Ai为第i个样点截面处环空流体过流面积，m2；Li为第i个样点截面处湿周长度，m；ai为第i个样点截面处裸眼的长轴长度，m；bi为第i个样点截面处裸眼的短轴长度，m；In the formula: D avg is the equivalent hydraulic diameter of the naked eye, m; A i is the annular fluid flow area at the cross section of the i-th sample point, m 2 ; Li is the wetted circumference length at the cross-section of the i -th sample point, m; a i is the long axis length of the naked eye at the ith sample point section, m; b i is the short axis length of the naked eye at the ith sample point section, m; 将步骤二中的第i个样点截面处环空流体过流面积Ai代入公式(4)，计算出裸眼平均轴向流速vavg；Substitute the annular fluid flow area A i at the cross section of the i-th sample point in the step 2 into formula (4), and calculate the naked-hole average axial flow velocity v avg ;
Figure FDA0002882810660000012
Figure FDA0002882810660000012
 式中：vavg为裸眼平均轴向流速，m/s；Ai为第i个样点截面处环空流体过流面积，m2；Q为环空流体流量，m3/s；In the formula: v avg is the average axial velocity of the naked eye, m/s; A i is the flow area of the annular fluid at the cross section of the ith sample point, m 2 ; Q is the flow rate of the annular fluid, m 3 /s; 步骤四：将步骤三中的裸眼等效水力直径Davg和裸眼平均轴向流速vavg代入公式(5)中，计算出裸眼流体平均剪切速率γavg；Step 4: Substitute the naked-hole equivalent hydraulic diameter D avg and the naked-hole average axial flow velocity v avg in the step 3 into formula (5), and calculate the naked-hole fluid average shear rate γ avg ;
Figure FDA0002882810660000021
Figure FDA0002882810660000021
 式中：γavg为裸眼流体平均剪切速率，1/s；Davg为裸眼等效水力直径，m；vavg为裸眼平均轴向流速，m/s；where: γ avg is the average shear rate of the naked-hole fluid, 1/s; D avg is the equivalent hydraulic diameter of the naked-hole, m; v avg is the average axial flow velocity of the naked-hole, m/s; 步骤五：将步骤四中的裸眼流体平均剪切速率γavg代入公式(6)中，计算出修正流性指数m；Step 5: Substitute the average shear rate γ avg of the naked-hole fluid in step 4 into formula (6), and calculate the modified fluidity index m;
Figure FDA0002882810660000022
Figure FDA0002882810660000022
 式中：m为修正流性指数，无量纲；n为流性指数，无量纲；K为流体稠度系数，Pa·Sn；γavg为裸眼流体平均剪切速率，1/s；τy为流体屈服值，Pa；where m is the modified fluidity index, dimensionless; n is the fluidity index, dimensionless; K is the fluid consistency coefficient, Pa· Sn ; γavg is the average shear rate of the naked-hole fluid, 1/s; τy is Fluid yield value, Pa; 步骤六：将步骤五中的修正流性指数m代入公式(7)中，计算出流体有效稠度系数Kef；Step 6: Substitute the revised fluidity index m in step 5 into formula (7), and calculate the fluid effective consistency coefficient K ef ;
Figure FDA0002882810660000023
Figure FDA0002882810660000023
 式中：Kef为流体有效稠度系数，Pa·Sn；K为流体稠度系数，Pa·Sn；m为修正流性指数，无量纲；Where: K ef is the effective fluid consistency coefficient, Pa·S n ; K is the fluid consistency coefficient, Pa·S n ; m is the modified fluidity index, dimensionless; 将步骤五中的修正流性指数m代入公式(8)中，计算出流体有效屈服值τef；Substitute the revised fluidity index m in step 5 into formula (8), and calculate the effective yield value τ ef of the fluid;
Figure FDA0002882810660000024
Figure FDA0002882810660000024
 式中：τef为流体有效屈服值，Pa；τy为流体屈服值，Pa；m为修正流性指数，无量纲；In the formula: τ ef is the effective yield value of fluid, Pa; τ y is the yield value of fluid, Pa; m is the modified fluidity index, dimensionless; 将步骤五中的修正流性指数m代入公式(9)中，计算出流体有效剪切速率γef；Substitute the modified fluidity index m in step 5 into formula (9), and calculate the fluid effective shear rate γ ef ;
Figure FDA0002882810660000025
Figure FDA0002882810660000025
 式中：γef为流体有效剪切速率，1/s；γavg为流体平均剪切速率，1/s；m为修正流性指数，无量纲；Where: γ ef is the effective shear rate of fluid, 1/s; γ avg is the average shear rate of fluid, 1/s; m is the modified fluidity index, dimensionless; 步骤七：将步骤六中的流体有效稠度系数Kef、流体有效屈服值τef和流体有效剪切速率γef代入公式(10)中，计算出流体有效粘度ηef；Step 7: Substitute the fluid effective consistency coefficient K ef , the fluid effective yield value τ ef and the fluid effective shear rate γ ef in the step 6 into formula (10), and calculate the fluid effective viscosity η ef ; ηef＝τef·γef -1+Kef·γef n-1 (10)η ef =τ ef ·γ ef -1 +K ef ·γ ef n-1 (10) 式中：ηef为流体有效粘度，Pa/s；Kef为流体有效稠度系数，Pa·Sn；τef为流体有效屈服值，Pa；γef为流体有效剪切速率，1/s；n为流性指数，无量纲；where η ef is the effective viscosity of the fluid, Pa/s; K ef is the effective consistency coefficient of the fluid, Pa·S n ; τ ef is the effective yield value of the fluid, Pa; γ ef is the effective shear rate of the fluid, 1/s; n is the fluidity index, dimensionless; 步骤八：将步骤七中的流体有效粘度ηef代入公式(11)中，计算出裸眼环空流动雷诺数Re；Step 8: Substitute the effective viscosity η ef of the fluid in Step 7 into formula (11), and calculate the Reynolds number Re of the open-hole annular flow;
Figure FDA0002882810660000026
Figure FDA0002882810660000026
 式中：Re为裸眼环空流动雷诺数，无量纲；ρ为流体密度，kg/m3；vavg为裸眼平均轴向流速，m/s；Davg为裸眼等效水力直径，m；ηef为流体有效粘度，Pa/s；In the formula: Re is the Reynolds number of the open-hole annular flow, dimensionless; ρ is the fluid density, kg/m 3 ; v avg is the average axial flow velocity of the naked-hole, m/s; D avg is the equivalent hydraulic diameter of the naked-hole, m; η ef is the effective viscosity of the fluid, Pa/s; 步骤九：将步骤八中的裸眼环空流动雷诺数Re代入公式(12)中，计算出范宁摩擦参数f；Step 9: Substitute the Reynolds number Re of the open-hole annular flow in Step 8 into formula (12) to calculate the Fanning friction parameter f;
Figure FDA0002882810660000031
Figure FDA0002882810660000031
 式中：f为范宁摩擦参数，无量纲；Re为环空流动雷诺数，无量纲；where f is the Fanning friction parameter, dimensionless; Re is the annular flow Reynolds number, dimensionless; 步骤十：将步骤一中的第i个样点截面与第i+1个样点截面间环空流动距离li(i＝1,2,3,…,k-2,k-1)代入公式(14)计算出环空流动距离ΔL，将步骤九中的范宁摩擦参数f代入公式(13)中，计算出裸眼层流环空流动压降ΔP；Step 10: Substitute the annular flow distance l i (i=1,2,3,...,k-2,k-1) between the i-th sample point section and the i+1-th sample point section in step 1 The annular flow distance ΔL is calculated by formula (14), and the Fanning friction parameter f in step 9 is substituted into formula (13) to calculate the open-hole laminar flow annular flow pressure drop ΔP;
Figure FDA0002882810660000032
Figure FDA0002882810660000032
 其中：in:
Figure FDA0002882810660000033
Figure FDA0002882810660000033
 式中：ΔP为裸眼层流环空流动压降，Pa；f为范宁摩擦参数，无量纲；vavg为裸眼平均轴向流速，m/s；ΔL为环空流动距离，m；Davg为裸眼等效水力直径，m；li为第i个样点截面与第i+1个样点截面间环空流动距离，m。where: ΔP is the pressure drop of the open-hole laminar annular flow, Pa; f is the Fanning friction parameter, dimensionless; v avg is the average axial flow velocity of the naked-hole, m/s; ΔL is the annular flow distance, m; D avg is the equivalent hydraulic diameter of the naked eye, m; li is the annular flow distance between the i -th sample point section and the i+1-th sample point section, m. 2.根据权利要求1所述的一种适用于超深井长裸眼井段的环空压降计算方法，其特征在于：所述的环空流动距离ΔL取值范围为1～9m。2 . A method for calculating annular pressure drop suitable for a long open-hole section of an ultra-deep well according to claim 1 , wherein the annular flow distance ΔL ranges from 1 to 9 m. 3 . 3.根据权利要求1所述的一种适用于超深井长裸眼井段的环空压降计算方法，其特征在于：所述的样点截面数量k取值范围为5～100。3 . The annulus pressure drop calculation method suitable for long open-hole sections of ultra-deep wells according to claim 1 , wherein the number k of the sample point cross-sections ranges from 5 to 100. 4 .
CN202110004857.0A 2021-01-04 2021-01-04 An annular pressure drop calculation method suitable for ultra-deep wells with long open-hole sections Active CN112727438B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110004857.0A CN112727438B (en) 2021-01-04 2021-01-04 An annular pressure drop calculation method suitable for ultra-deep wells with long open-hole sections

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110004857.0A CN112727438B (en) 2021-01-04 2021-01-04 An annular pressure drop calculation method suitable for ultra-deep wells with long open-hole sections

Publications (2)

Publication Number Publication Date
CN112727438A CN112727438A (en) 2021-04-30
CN112727438B true CN112727438B (en) 2022-02-18

Family

ID=75589654

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110004857.0A Active CN112727438B (en) 2021-01-04 2021-01-04 An annular pressure drop calculation method suitable for ultra-deep wells with long open-hole sections

Country Status (1)

Country Link
CN (1) CN112727438B (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001002832A1 (en) * 1999-07-06 2001-01-11 Sofitech N.V. Modelling the rheological behaviour of drilling fluids as a function of pressure and temperature
CN110929458A (en) * 2019-11-15 2020-03-27 长江大学 Method for calculating annulus comprehensive hydraulic equivalent diameter of irregular borehole section
CN111173489A (en) * 2020-01-06 2020-05-19 西南石油大学 Method for calculating free settling velocity of fiber-containing proppant clusters in fracture
EP3730926A1 (en) * 2019-04-26 2020-10-28 Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ Stiftung des Öffentlichen Rechts des Lands Brandenburg Method and system for measuring or monitoring the viscosity of flowing materials

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007145734A2 (en) * 2006-06-07 2007-12-21 Exxonmobil Upstream Research Company Compressible objects having partial foam interiors combined with a drilling fluid to form a variable density drilling mud
WO2008127237A1 (en) * 2007-04-12 2008-10-23 Halliburton Energy Services, Inc. Borehole characterization
US9394783B2 (en) * 2011-08-26 2016-07-19 Schlumberger Technology Corporation Methods for evaluating inflow and outflow in a subterranean wellbore
WO2015175784A1 (en) * 2014-05-14 2015-11-19 Board Of Regents, The University Of Texas System Systems and methods for determining a rheological parameter

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001002832A1 (en) * 1999-07-06 2001-01-11 Sofitech N.V. Modelling the rheological behaviour of drilling fluids as a function of pressure and temperature
EP3730926A1 (en) * 2019-04-26 2020-10-28 Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ Stiftung des Öffentlichen Rechts des Lands Brandenburg Method and system for measuring or monitoring the viscosity of flowing materials
CN110929458A (en) * 2019-11-15 2020-03-27 长江大学 Method for calculating annulus comprehensive hydraulic equivalent diameter of irregular borehole section
CN111173489A (en) * 2020-01-06 2020-05-19 西南石油大学 Method for calculating free settling velocity of fiber-containing proppant clusters in fracture

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
Simplified modeling of YPL fluid flow through a concentric elliptical;Tang Ming等;《Journal of Petroleum Science and Engineering》;20171215;第225-232页 *
幂律流体螺旋层流流动压降简化模型;翟科军等;《石油机械》;20201031;第48卷(第10期);第22-26页 *
赫巴流体在圆管内层流流动理论及混凝土泵送应用实例;王衍伟等;《混凝土与水泥制品》;20180131;第10-15页 *

Also Published As

Publication number Publication date
CN112727438A (en) 2021-04-30

Similar Documents

Publication Publication Date Title
Song et al. Experimental study on the wellbore-cleaning efficiency of microhole-horizontal-well drilling
Li et al. Research advances and debates on tubular mechanics in oil and gas wells
Delwiche et al. Slimhole drilling hydraulics
CN109854237B (en) A method and system for predicting bottomhole pressure
Ozbayoglu et al. Critical fluid velocities for removing cuttings bed inside horizontal and deviated wells
CN109598024A (en) The drilling well waterpower optimization method and equipment coupled based on wellbore cleaning with annular pressure
Taghipour et al. Experimental study of hydraulics and cuttings transport in circular and noncircular wellbores
Cayeux et al. Challenges and solutions to the correct interpretation of drilling friction tests
Abbas et al. Comprehensive experimental investigation of hole cleaning performance in horizontal wells including the effects of drill string eccentricity, pipe rotation, and cuttings size
Zhao et al. Combined control mechanism of weight on bit and rate of penetration with a downhole robot in the coiled-tubing drilling process
Shadizadeh et al. An experimental modeling of cuttings transport for an Iranian directional and horizontal well drilling
Sun et al. A novel transient hole cleaning algorithm for horizontal wells based on drift-flux model
Krishna et al. Simplified predictive model for downhole pressure surges during tripping operations using power law drilling fluids
CN112727438B (en) An annular pressure drop calculation method suitable for ultra-deep wells with long open-hole sections
Wang et al. Dynamic wellbore stability analysis based on thermo-poro-elastic model and quantitative risk assessment method
Li et al. Extended-reach well in shale formation: what is the maximum measured depth while coiled tubing drilling
Zhang et al. Wellbore pressure model for drilling fluid in ultra-deep rock salt formations at high temperatures and pressures
Li et al. Research on intelligent judgment method of natural gas hydrate drilling risk
CN110457866B (en) Friction resistance prediction method and friction resistance reduction method in whole sliding drilling process
Menand et al. Safely Exceeding Buckling Loads in Long Horizontal Wells: Case Study in Shale Plays
Liu et al. Fatigue failure analysis of drilling tools for ultra-deep wells in shunbei block
Shi et al. Numerical study of a flow field near the bit for a coiled-tubing partial underbalanced drilling method
Xie et al. Improving Drilling Efficiency Using Intelligent Decision System for Drilling in Bohai Oilfield Based on Big Data
Xuejun et al. Comparative analysis of the pressure loss from the circulation of drilling fluid during microhole drilling with the use of coiled tubing
Mingjian et al. Research on a Calculation Model of Cable Tension and Pumping Displacement of a Logging Tool String of Horizontal-Well Drillpipes

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant