RU2413835C1 - Procedure for utilisation of drilling waste - Google Patents

Abstract

FIELD: gas-and-oil producing industry.

SUBSTANCE: here is disclosed procedure of reagent capsulation of consolidated material with utilised drilling waste. According to the invention as consolidating material there is used mixture of reagent of capsulation and large-tonnage waste of cement industry in form of cement powder at the following ratio of components, wt %: reagent of capsulation 20-30, cement powder 15-30, drilling waste - the rest.

EFFECT: raised efficiency of utilisation of drilling waste at simultaneous saving labour and material expenditures, also utilisation of local large-tonnage industrial powder-like waste of other branches of industry and simultaneous utilisation of oil slime at drilling oil wells.

4 cl, 5 tbl

Description

The invention relates to the protection of the environment during the construction of oil wells on land, in particular to methods for the disposal of drilling waste.

A known method of neutralizing spent drilling mud and sludge by the curing method, including storing the spent drilling mud in an earthen sludge barn, mixing with Portland cement and subsequent disposal (see Shishov V.A., Shemetov V.Yu. About curing drilling fluids and sludge with Portland cement. Proceedings of VNIIKRneft. - Technique and technology for flushing and fixing wells. Krasnodar. - 1982. - P.28-35).

The disadvantages of this method include the use as a consolidating material of Portland cement - an expensive building material.

The reagent encapsulation method is a close method for the same purpose in the method for producing the reagent. The reagent encapsulation method is based on the ability of calcium oxide to form capsules with contaminated materials that isolate toxic components from the environment as a result of chemical reactions (see dissertation for the degree of candidate of technical sciences Logunova Yu.V. “Improving the technology and equipment for disposal oil-contaminated materials by the method of reagent encapsulation ", 2009). This method involves the preparation of a hydrophobic reagent and mixing it with contaminated material.

The hydrophobic reagent absorbs the hydrophobic organic phase in the first stage and then reacts with the water present to form a powdery material. During the encapsulation process, a solid dispersed material is formed with pronounced hydrophobic properties. The resulting material is suitable for use in the construction of tanks, as their pillows.

The description of the prototype refers to the use of encapsulation of bitumen of oil construction grade BN 70/30 as a water repellent agent. The disadvantages of the method are low efficiency, high energy consumption (heating of bitumen over 200 ° C) and high cost due to the use of bitumen. In addition, in the known method, subsequent destruction of the shells due to the negative effects of environmental factors. In addition, this method does not provide for the disposal of bulk waste drilling-oil sludge.

The technical task is to increase the efficiency of drilling waste disposal while saving labor and material costs, the disposal of local large-tonnage industrial powdery waste from other industries (in particular cement production) with harmful dust-forming properties, the conversion of production waste from the category of pollutants of environmental objects to material for its protection, with the simultaneous disposal of oil sludge when drilling oil wells.

The problem is solved in that in a method for the disposal of drilling waste by the method of reagent encapsulation, comprising mixing a consolidating material consisting of encapsulation reagent based on calcium oxide and water repellent, with drilling waste, according to the invention, the cement industry waste in the form of cement dust is additionally used in the following ratio of components , wt.%:

Encapsulation Reagent 20-30 Cement dust 15-30 Drilling waste Rest

The composition of the encapsulation reagent includes calcium oxide CaO and oil sludge in the following ratio, wt.%:

Calcium oxide 70-80 Oil sludge 20-30

In addition, to further protect the capsules from the negative effects of environmental factors, a polymer additive in an amount of 1-2 wt.% Is added to the consolidated material with constant stirring. As a polymer additive, an all-weather aqueous polymer (PVV) is used according to TU 2216-002-75821482-2006.

The invention consists in the following.

In a cylindrical reactor with a stirrer, under normal conditions, quicklime CaO and oil sludge are mixed until a homogeneous hydrophobic encapsulation reagent powder is formed. The resulting encapsulation reagent is removed from the reactor and loaded into a storage barn, where it is mixed with drilling waste. Upon reaching a homogeneous mass, cement dust and a polymer additive are added to the resulting mixture of encapsulation reagent and drilling waste. After mixing the entire mass, a consolidated material is formed, which is removed from the barn and shipped to the consumer.

To establish the optimal ratio of CaO and oil sludge in the encapsulation reagent, the following experiment was performed. Quicklime CaO was mixed with oil sludge (oil and oil products content of at least 15%) in an amount of 50-60, 70-80, 80-90 wt.% To obtain a hydrophobized powder. As can be seen from table 1, the most optimal for the encapsulation reagent is the following CaO content of 70-80%. In this case, a light brown powder is formed. This sample allows reagent encapsulation.

In order to consolidate drilling waste using an encapsulation reagent, the following experiment was carried out. Drilling waste was mixed with the encapsulation reagent at room temperature in the following amounts of 40-60, 60-70, 70-80 wt.%.

Evaluation of the effectiveness of the proposed consolidating composition was carried out in laboratory conditions on a certified Igla Vika device (IW according to TU 25-08255075 1978) at the Department of Drilling of Ural State Technical University.

The essence of the method is to determine the degree of immersion of the needle in the consolidated material. The prepared sample is placed in a ring located on a polished steel bottom plate and the needle is lowered. The degree of curing is estimated by the height of the layer of material that is not penetrable by the needle. For liquid, amorphous and bulk materials, this height is h = 0 mm, i.e. there is no material hardness. When the hardness of the material is set, the needle rises higher. The hardness of the material is measured in the range from 0 to 40 mm. Maximum hardness is achieved at h = 40 mm. If the needle stopped at a distance above 1 mm, this indicates an effective consolidation of drilling waste, if less than 1 mm, then a low degree of consolidation. As can be seen from table 2, the best recipe for obtaining a cured bulk material is mixing an encapsulation reagent with drilling waste in an amount of 40-60%, while a consolidated powdery reagent is formed, but this sample does not have sufficient hardness. Tests on the Wick device also showed h = 0.5 mm.

To increase the efficiency of solidification of drilling waste, it was proposed to use cement dust. The following experiment was set to determine the optimal recipe for consolidated material.

The encapsulation reagent was mixed with cement dust and drilling waste. Cement dust was added in the following amounts 0-15, 15-30, 30-40 wt.%. The degree of consolidation was judged by the well-known method of “Testing with a Vic needle”. As can be seen from table 3, the optimal consolidated material is obtained when the content of the encapsulation reagent is 20-30 wt.% And cement dust 15-30 wt.%. Testing with a Vick needle in this case shows h = 1.5 mm.

In order to determine the recipe for consolidated material with additional protection against the negative effects of environmental factors, the following experience was set. The consolidated material was based on a sample based on encapsulation reagent and cement dust, discussed above, with the following components wt.%:

Cement industry waste in the form of Cement dust 15-30 Encapsulation Reagent 20-30 Drilling waste Rest

The resulting consolidated waste was treated with PVV polymer material (according to TU 2216-002-75821482-2006) in amounts of 0-1, 1-2, 2-5 wt.%.

As can be seen from table 4, the optimum is the content of PVV 1-2 wt.%. In this case, an additional uniform film forms on the entire surface of the capsules. Testing with a Vick needle shows h = 1.5 mm.

To study the influence of negative environmental factors, in particular acid rain, the following experiment was put on the consolidated material. Under laboratory conditions, an acidic medium was prepared based on 0.1 n HCl. Further, consolidated material and material treated with PVV were immersed in this medium for 24 hours. As can be seen from table 5, the consolidated material is acidified in a medium of 0.1 n HCl (pH decreases from 11 to 6.5), while the hardness of the material decreases from h = 1.5 mm to h = 1.0 mm.

The consolidated material pretreated with PVV is slightly acidified in 0.1 N HCl (pH decreases from 11 to 10), while the hardness of the material decreases from h = 1.5 mm to h = 1.4 mm. As a result of the experiments (table 1-5), the most effective ratio of the selected components was determined, wt.%:

Cement industry waste in the form of Cement dust 15-30 Encapsulation Reagent 20-30 PVC material 1-2 Drilling waste Rest

Table 1
Composition and Characterization of Encapsulation Reagent Component Composition, wt.% Characteristic The composition of the encapsulation reagent: 1. CaO 50-60 70-80 80-90 2. oil sludge > 40 20-30 <10-20 When preparing the reagent, a significant amount of heat is released, the mass thickens with stirring and does not form a powder. The optimal ratio, a light brown powder is formed. This sample allows reagent encapsulation. This ratio, due to the low content of oil sludge does not provide hydrophobization of the encapsulation reagent.

table 2
The composition and characteristics of the consolidated material Consolidating material: Composition,% wt. 1. Encapsulation reagent Characteristic <20 20-30 > 30 2. Drilling waste > 80 40-60 <70 The encapsulation process does not occur due to insufficient encapsulation reagent. Testing with a Vick needle shows h = 0. The optimal ratio. A consolidated reagent with a strong shell is formed. Testing with a Vick needle shows h = 0.5. The encapsulation process does not occur, a dense heterogeneous mass is formed. Testing with a Vick needle shows h = 0.

Table 3
The composition and characteristics of the consolidated material with the addition of cement dust Consolidating material: Composition, wt.% 1. Encapsulation reagent Characteristic <20 20-30 > 30 2. Cement dust 0-15 15-30 30-40 A gel-like mass is formed that does not allow the consolidation of waste. The optimal ratio, as there is a uniform distribution throughout the volume. Mixing of the ingredients is difficult and is accompanied by the formation of a heterogeneous mixture. 3. Drilling waste <40 40-60 > 60 Inappropriate use, increase the cost of disposal. Testing with a Vick needle shows h = 1 mm. The optimal ratio. A consolidated reagent with a strong shell is formed. Testing with a Vick needle shows h = 1.5 mm. The encapsulation process does not occur, a dense heterogeneous mass is formed. Testing with a Vick needle shows h = 1 mm.

Table 4
The composition and characteristics of the consolidated material (when adding PVV) Consolidating material: Composition, wt.% 1. Encapsulation reagent Characteristic <20 20-30 > 30 Insufficient curing reagent. The optimal ratio is the curing of the mass of drilling waste, capsules are formed. There is no complete extinguishing of lime, encapsulation is uneven throughout the volume. 2. Cement dust <15 15-30 > 30 A gel-like mass is formed that does not allow the consolidation of waste. The optimal ratio, as there is a uniform distribution throughout the volume. Mixing of the ingredients is difficult and is accompanied by the formation of a heterogeneous mixture. 3. Drilling waste <40 40-60 > 60 Inappropriate use, increase the cost of disposal. The optimal ratio. A consolidated reagent with a strong shell is formed. The encapsulation process does not occur, a dense heterogeneous mass is formed. 4. All-weather water polymer 0-1 1-2 2-5 Not enough to form a polymer film. The optimal ratio, an additional uniform film is formed on the surface of the capsules. It complicates the mixing of ingredients and is accompanied by the formation of a heterogeneous mixture, significantly increases the cost of disposal of a unit of drilling waste. Testing with a Vick needle shows h = 1 mm. Testing with a Vick needle shows h = 1.5 mm. Testing with a Vick needle shows h = 1.5 mm.

Table 5
Characterization of consolidated material treated with HCl and PVV Reagent PH value Testing with a needle of Vic, mm Initial Final Initial Final Consolidated material eleven eleven 1,5 1,5 Hydrochloric acid 0.1 n HCl 0.5 0.5 - - Consolidated Material +0.1 n HCl eleven 6.5 1,5 1,0 Consolidated material treated with PVV + 0.1 n HCl eleven 10 1,5 1.4

Claims (4)

1. A method of utilizing drilling waste by the method of reagent encapsulation, comprising mixing a consolidating material consisting of encapsulation reagent based on calcium oxide and a hydrophobizing agent with drilling waste, characterized in that the cement industry waste is additionally used in the form of cement dust in the following ratio of components, wt.% :
Encapsulation Reagent 20-30 Cement dust 15-30 Drilling waste rest 2. The method according to claim 1, characterized in that in the composition of the encapsulation reagent as a water repellent oil sludge is used in the following ratio of components, wt.%:
Calcium oxide 70-80 Oil sludge 20-30 3. The method according to claim 1, characterized in that for additional protection of the capsules from the negative effects of environmental factors, a polymer additive in an amount of 1-2 wt.% Is added to the consolidated material with constant stirring. 4. The method according to claim 3, characterized in that as a polymer additive, an all-season aqueous polymer (PVV) is used.