Organic consolidation material for leaking stoppage of oil-based drilling fluid and construction method

Abstract

The invention discloses an organic consolidation material for leaking stoppage of oil-based drilling fluid and a construction method of the organic consolidation material. The organic consolidation material comprises the following components in parts by weight: 100 parts of epoxy resin, 5-30 parts of a curing agent, 0-0.24 part of a curing time regulator, 30-80 parts of a diluent and 0-300 parts of a proppant. When the material is used as a leaking stoppage material, all the components are uniformly mixed and then injected into a specified construction point within 5 hours, the mixture is pressurized and built into a stratum, then a well is closed for waiting for cement setting for 8-24 hours, and after the well is opened and drilled, subsequent construction operation can be carried out; the organic consolidation material for leaking stoppage of the oil-based drilling fluid is an organic thermal initiation consolidation material and can be suitable for a stratum environment with the temperature range of 60-180 DEG C, and the curing time of the organic consolidation material can be adjusted within the range of 0.6-8 h through a curing time regulator; in the actual leaking stoppage construction process, the material is high in cementing strength, good in compressive strength and good in compatibility with oil-based drilling fluid, the leaking stoppage strength is met, drilling is easy after leaking stoppage, and the risk of well track deviation is effectively reduced.

Description

Technical Field

[0001] The invention relates to the field of oil field drilling, and in particular to an organic consolidation material for plugging leaks in oil-based drilling fluid and a construction method. Background Art

[0002] In recent years, the exploitation of unconventional oil and gas such as shale gas has received increasing attention. Studies have shown that 75% of the world's drilling formations are shale formations. Shale formations have the characteristics of high content of hard and brittle minerals, strong water sensitivity, and developed bedding and microcracks, resulting in 90% of shale formations having wellbore instability problems, and the losses caused by this account for about 10% of the total cost of drilling operations. Oil-based drilling fluid is an important mud technology to solve the problem of wellbore instability in shale formations. Although oil-based drilling fluids are expensive and easy to pollute the environment, they have good high temperature resistance, lubricity and wellbore stability in shale formations, which is unmatched by water-based drilling fluids. Compared with water-based drilling fluids, when drilling into specific formations, oil-based drilling fluids have a shorter drilling cycle, so the total drilling cost is lower. However, the leakage problem of oil-based drilling fluids is a major problem that restricts drilling with oil-based drilling fluids.

[0003] At present, there are few materials specifically used for plugging leaks in oil-based drilling fluids. When leakage occurs, water-based drilling fluid plugging materials are mainly used. Water-based plugging materials do not expand or bridge to form a network under the conditions of oil-based drilling fluids. The plugging layer formed has low strength, is not dense, and is prone to re-leakage. Cement consolidation plugging is a better way to plug leaks, but traditional cement slurry has serious compatibility problems with oil-based drilling fluids. After mixing oil-based drilling fluid with cement slurry, severe emulsification will occur to form an oil-in-water emulsion. On the one hand, the rheological properties of cement slurry and oil-based drilling fluid are seriously deteriorated, and even lose fluidity; on the other hand, the cement slurry is dispersed into discontinuous particles or droplets, making the cement slurry "coagulated but not solid", unable to form overall strength, and greatly reducing the compressive strength. Summary of the invention

[0004] The purpose of the present invention is to provide an organic consolidating material for plugging leaks in oil-based drilling fluids, which can solve the problem of poor compatibility between plugging materials and oil-based drilling fluids in plugging leaks in oil-based drilling fluids.

[0005] Another object of the present invention is to provide a construction method for using the above-mentioned organic solidifying material for oil-based drilling fluid plugging as an oil-based drilling fluid plugging material.

[0006] To this end, the technical solution of the present invention is as follows:

[0007] An organic solidifying material for plugging leaks in oil-based drilling fluids, comprising, by weight, 100 parts of epoxy resin, 5 to 30 parts of curing agent, 0 to 0.3 parts of curing time regulator, 30 to 80 parts of diluent and 0 to 300 parts of proppant; wherein the epoxy resin is one or a mixture of any proportion of two or more of bisphenol A epoxy resin, alicyclic epoxy resin, bisphenol F epoxy resin or phenolic epoxy resin; the curing agent is diethylaminopropylamine, diaminodiphenyl sulfone, diaminodiphenylmethane, 4,4'-diaminobenzene, diaminodiphenylmethane, diaminobenzene ... Methyldi(2-chloroaniline), 4-chloro-o-phenylenediamine, dicyandiamide, melamine, 4-trifluoromethyl-o-phenylenediamine, m-phenylenediamine, or a mixture of two or more thereof in any proportion; the diluent is butyl glycidyl ether, ethylene glycol diglycidyl ether, phenyl glycidyl ether, alkylene glycidyl ether, benzyl glycidyl ether, benzyl alcohol, dibutyl phthalate, butyl acetate, xylene, N,N-dimethylformamide, N,N-dimethylacetamide, or a mixture of two or more thereof in any proportion.

[0008] Preferably, the curing time regulator is a tertiary amine, specifically one or a mixture of two or more of triethanolamine, N,N-dimethylaniline, benzyldimethylamine, o-hydroxybenzyldimethylamine, tridimethylaminomethylphenol, triethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 3,3-(4-methyl-1,3-phenylene)bis(1,1-dimethylurea) in any proportion.

[0009] Preferably, the proppant is one or a mixture of any proportion of two or more of calcium carbonate, barite, sand, iron ore powder, calcium sulfate, fruit shell, sand, tree fiber, and galena.

[0010] Preferably, the particle size of the proppant is 20 mesh to 300 mesh.

[0011] A construction method using the above-mentioned organic consolidating material for plugging leaks in oil-based drilling fluids, comprising the following steps:

[0012] S1. Evenly mix epoxy resin, curing agent, curing time regulator, diluent and proppant using a cement truck or a mud batching tank to prepare an organic consolidation material for plugging leaks in oil-based drilling fluid;

[0013] S2, injecting the organic consolidation material for plugging oil-based drilling fluid prepared in step S1 into the designated construction point within 5 hours, and pressurizing it into the formation;

[0014] S3. Shut down the well and wait for 8 to 24 hours for solidification. After the well is opened and drilled, subsequent construction work can be carried out.

[0015] Compared with the prior art, the organic solidifying material for plugging leaks in oil-based drilling fluid is an organic thermally induced solidifying material, which can be used in formation environments with a temperature range of 60°C to 180°C, and the solidification time can be adjusted within the range of 0.6h to 8h through a solidification time regulator; in the actual plugging construction process, the material not only has high bonding strength and good compressive strength, but also has good compatibility with the oil-based drilling fluid, which not only meets the plugging strength requirements, but also meets the requirements of easy drilling after plugging, effectively reducing the risk of wellbore trajectory deviation. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with specific examples, but the following examples are by no means intended to limit the present invention in any way.

[0017] Example 1

[0018] 100g of bisphenol A epoxy resin (epoxy resin E-51), 25g of diaminodiphenyl sulfone, a certain mass of o-hydroxybenzyl dimethylamine and 30g of dibutyl phthalate were uniformly mixed to prepare an organic solidifying material for plugging oil-based drilling fluid; wherein o-hydroxybenzyl dimethylamine was used as a curing time regulator, and its addition amount was variable.

[0019] Example 2

[0020] 100g of bisphenol F epoxy resin (epoxy resin NPEF-170, epoxy equivalent 160g / eq~180g / eq, Henan Shuizhihuan Industrial Co., Ltd.), 30g of diaminodiphenylmethane, a certain mass of 2,4,6-tris(dimethylaminomethyl)phenol, 70g of dibutyl phthalate and 100g of calcium carbonate (80 mesh) were uniformly mixed to prepare an organic consolidating material for plugging oil-based drilling fluid; wherein, 2,4,6-tris(dimethylaminomethyl)phenol was used as a curing time regulator, and its addition amount was variable.

[0021] Example 3

[0022] 100g of bisphenol A epoxy resin (epoxy resin E-51), 5g of melamine, a certain mass of o-hydroxybenzyl dimethylamine, 60g of dibutyl phthalate, 20g of phenyl glycidyl ether, 50g of sand (60 mesh) and 20g of fruit shell (20 mesh) are uniformly mixed to prepare an organic consolidating material for plugging leaks in oil-based drilling fluid; wherein o-hydroxybenzyl dimethylamine is used as a curing time regulator, and its addition amount is variable.

[0023] Example 4

[0024] 100g of bisphenol A epoxy resin (epoxy resin E-51), 15g of 4,4'-methylenebis(2-chloroaniline), 60g of dibutyl phthalate, a certain mass of 3,3-(4-methyl-1,3-phenylene)bis(1,1-dimethylurea), 150g of barite (300 mesh) and 30g of fruit shell (20 mesh) are uniformly mixed to prepare an organic consolidating material for plugging leaks in oil-based drilling fluid; wherein 3,3-(4-methyl-1,3-phenylene)bis(1,1-dimethylurea) is used as a curing time regulator, and its addition amount is variable.

[0025] Comparative Example 1

[0026] 100g of bisphenol A epoxy resin (epoxy resin E-51), 25g of diaminodiphenyl sulfone and a certain amount of o-hydroxybenzyl dimethylamine were uniformly mixed to prepare an oil-based drilling consolidation plugging material.

[0027] The apparent viscosity of the oil-based drilling consolidation plugging material was measured at 25°C using a dynamic rheometer (MARS60, Hack, Germany) at a speed of 300 r / min to be 13200 mPa·s. The viscosity is too high to meet the on-site pumping requirements for drilling plugging applications.

[0028] Performance Testing:

[0029] (I) Leakage plugging performance test:

[0030] The rheological properties, thickening time, compressive strength, and bonding strength of the oil-based drilling consolidation plugging materials prepared in Examples 1 to 4 were tested in turn; specifically,

[0031] (1) Rheological properties test: The plugging formula is tested for apparent viscosity using a six-speed viscometer, the model of which is ZNN-D6. The plugging agent is tested for apparent viscosity at a speed of 600 r / min. Pour the plugging agent into the test cup, adding about 350 mL, slightly below the scale line in the cup. Turn on the power, adjust the speed to 600 r / min, and read the value after stabilization. 1 / 2 of the value is the apparent viscosity of the plugging agent. The annual viscosity of epoxy resin E-51 is measured using a dynamic rheometer at a speed of 300 r / min.

[0032] (2) Thickening time and compressive strength test: Place the prepared plugging material in a cement slurry thickener, set the preset temperature, pressurize to 10 MPa, and heat up at a rate of 5°C / min. Start timing when the temperature reaches the preset temperature. When the viscosity rises to 4 times the initial viscosity, record the thickening time. Then transfer the sample to a 50 mL glass bottle, discard the excess, place the glass bottle in a 400 mL stainless steel mud aging tank, and introduce nitrogen at 1 MPa. Place it upright in an oven and heat for 24 hours. Take out the sample and test the compressive strength of the sample using a 10000 rpm testing machine. It should be noted that the thickening time refers to the time required for the viscosity of the plugging agent to increase by 4 times after heating; the compressive strength refers to the strength required to compress the material by 50%; the bonding strength refers to the strength required to shear and peel the rock surfaces bonded by the plugging agent. Among them, the 10000 rpm testing machine is CTM2100, purchased from Xieqiang Instrument Manufacturing (Shanghai) Co., Ltd.

[0033] (3) Bond strength test: Apply the plugging agent to the contact surface of two cubic cement blocks of the same size (50×50×50mm), with a contact area of ​​25cm 2 , heated for 24 hours at the corresponding temperature (consistent with the heating temperature during the thickening time determination), and then measured the minimum shear force F when two cement blocks crack and slide along the contact surface at room temperature using a rock direct shear tester. min , and the bond strength is calculated based on the contact area S, which is: P 胶 =F min / S. The rock direct shear test machine is of model YSZJ, purchased from Chengdu Donghua Excellence Technology Co., Ltd.

[0034] The following Table 1 shows the performance test results of the oil-based drilling consolidation plugging material prepared in Example 1.

[0035] Table 1:

[0036]

[0037] It can be seen from the test results in Table 1 that the oil-based drilling consolidation plugging material prepared in Example 1 can achieve material curing time adjustable in the range of 2h to 8h under the regulating effect of o-hydroxybenzyl dimethylamine as a curing time regulator, has a good curing time adjustment effect, and meets the safety construction requirements; at the same time, the oil-based drilling consolidation plugging material can be applied to the downhole temperature environment in the range of 60°C to 120°C, meets the temperature requirements of the leakage formation in general drilling construction, and has a compressive strength of 6MPa to 9.5MPa and a bonding strength of 1.6MPa to 2.0MPa, that is, it meets the strength requirements of the plugging material for drilling plugging.

[0038] Table 2 below shows the performance test results of the oil-based drilling consolidation plugging material prepared in Example 2.

[0039] Table 2:

[0040]

[0041] From the test results in Table 2, it can be seen that the oil-based drilling consolidation plugging material prepared in Example 2 can be adjusted in the range of 1h to 5h in a downhole environment of 60°C to 70°C under the regulation of 2,4,6-tris(dimethylaminomethyl)phenol as a curing time regulator, and is suitable for plugging leaks in lost formations with a formation temperature of about 60°C; at the same time, the compressive strength of the oil-based drilling consolidation plugging material is 8.7MPa to 11MPa, and the bonding strength is 1.6MPa to 1.8MPa, which meets the strength requirements of the drilling plugging material.

[0042] Table 3 below shows the performance test results of the oil-based drilling consolidation plugging material prepared in Example 3.

[0043] Table 3:

[0044]

[0045] From the test results in Table 3, it can be seen that the oil-based drilling consolidation plugging material prepared in Example 3 can be adjusted in the range of 2h to 6h in an underground environment of 120°C to 180°C under the regulating effect of o-hydroxybenzyl dimethylamine as a curing time regulator, and has a good curing time adjustment effect, ensuring the safety of plugging construction; at the same time, the compressive strength of the oil-based drilling consolidation plugging material is 7.5MPa to 11.5MPa, and the bonding strength is 1.8MPa to 2.2MPa, which meets the strength requirements of the plugging material for drilling plugging.

[0046] Table 4 below shows the performance test results of the oil-based drilling consolidation plugging material prepared in Example 4.

[0047] Table 4:

[0048]

[0049] From the test results in Table 4, it can be seen that the oil-based drilling consolidation plugging material prepared in Example 3 can be adjusted in the range of 0.6h to 7h in an underground environment of 60°C to 120°C under the regulation of 3,3-(4-methyl-1,3-phenylene)bis(1,1-dimethylurea) as a curing time regulator, and has a good curing time adjustment effect, ensuring the safety of plugging construction; at the same time, the compressive strength of the oil-based drilling consolidation plugging material is 9.5MPa to 13MPa, and the bonding strength is 1.6MPa to 2.0MPa, which meets the strength requirements of the plugging material for drilling plugging.

[0050] (II) Compatibility evaluation test:

[0051] The compatibility test of the oil-based drilling consolidation plugging materials prepared in Example 3 and Example 4 was carried out respectively; specifically, step 1: preparing an oil-based drilling fluid, the specific formula of which is: 1500g white oil, 60g primary emulsifier BZ-OPE, 60g auxiliary emulsifier BZ-OSE, 12g flow regulator BZ-ORM, 60g filtrate reducer BZ-OFL, 375g 25% calcium chloride aqueous solution and 2700g barite powder; wherein the primary emulsifier BZ- OPE, auxiliary emulsifier BZ-OSE, and flow regulator BZ-ORM are all commercially available products produced by China National Petroleum Corporation Bohai Drilling Engineering Co., Ltd.; Step 2: 400g of organic consolidating material for oil-based drilling fluid plugging and 80g of oil-based drilling fluid prepared by step 1 are mixed and stirred evenly, and placed at 120°C for aging and thickening time; and 24 hours after the thickening is completed, the bonding strength of the rock sample and the compressive strength of the cured sample are tested; the specific test results are shown in Table 5 below.

[0052] Table 5:

[0053]

[0054] It can be seen from the test structure in Table 5 that the oil-based drilling consolidation plugging material added with the present application has good compatibility with the oil-based drilling fluid system; not only a small amount of oil-based drilling fluid mixed with the consolidation system has little effect on the consolidation system, but also a small amount of consolidation system mixed with the oil-based drilling fluid has little effect on the performance of the oil-based drilling fluid, that is, it meets the requirements of plugging construction.

[0055] In addition, 100 g of the oil-based drilling consolidation plugging material prepared in Example 4 was mixed with 400 g of oil-based drilling fluid and aged at 150° C. for 24 h to evaluate the effect of the addition of the oil-based drilling consolidation plugging material on the comprehensive performance of the oil-based drilling fluid. The test results are shown in Table 6 below.

[0056] Table 6:

[0057]

[0058] It can be seen from the test results in Table 6 that the oil-based drilling fluid system to which the oil-based drilling consolidation plugging material of the present application is added is aged for 24 hours at the corresponding aging temperature, and the rheological properties and filtration loss reduction performance of the system meet the requirements of standard GB / T29170-2012.

[0059] (III) Pressure bearing capacity performance evaluation:

[0060] The pressure bearing capacity of the oil-based drilling consolidation plugging materials prepared in Example 3 and Example 4 was evaluated respectively; wherein, 40 mesh sand was filled in the high-pressure filter loss instrument to simulate the leaking layer, and 3 cm of the drilling consolidation plugging material was pressed in. After heating at the corresponding temperature for 24 hours, it was pressurized so that the upper and lower inlet and outlet pressure difference of the high-temperature and high-pressure filter loss instrument was 7 MPa, and the leakage of the experimental system was tested within 30 minutes.

[0061] The specific test results are shown in Table 7 below.

[0062] Table 7:

[0063] Test samples Heating temperature / ℃ Filtrate loss / mL Leakage plugging material 1 60 0 Leakage plugging material 1 120 0 Leakage plugging material 2 180 0

[0064] It can be seen from the test results in Table 7 that the pressure bearing capacity of the oil-based drilling consolidation plugging material seat plugging material of the present application can reach more than 7MPa.

Claims

1. An organic consolidating material for plugging leaks in oil-based drilling fluids, characterized in that: The invention comprises 100 parts of epoxy resin, 5 to 30 parts of curing agent, 0 to 0.3 parts of curing time regulator, 30 to 80 parts of diluent and 0 to 300 parts of proppant in parts by weight; wherein the epoxy resin is at least one of bisphenol A epoxy resin, alicyclic epoxy resin, bisphenol F epoxy resin or phenolic epoxy resin; the curing agent is at least one of diethylaminopropylamine, diaminodiphenyl sulfone, diaminodiphenylmethane, 4,4'-methylenebis(2-chloroaniline), 4-chloro-o-phenylenediamine, dicyandiamide, melamine, 4-trifluoromethyl-o-phenylenediamine and m-phenylenediamine; the diluent is at least one of butyl glycidyl ether, ethylene glycol diglycidyl ether, phenyl glycidyl ether, alkylene glycidyl ether, benzyl glycidyl ether, benzyl alcohol, dibutyl phthalate, butyl acetate, xylene, N,N-dimethylformamide and N,N-dimethylacetamide.

2. The organic consolidating material for plugging leaks in oil-based drilling fluid according to claim 1, characterized in that: The curing time regulator is a tertiary amine, specifically one of triethanolamine, N,N-dimethylaniline, benzyldimethylamine, o-hydroxybenzyldimethylamine, tridimethylaminomethylphenol, triethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 3,3-(4-methyl-1,3-phenylene)bis(1,1-dimethylurea) or a mixture of two or more in any proportion.

3. The organic consolidating material for plugging leaks in oil-based drilling fluid according to claim 1, characterized in that: The proppant is at least one of calcium carbonate, barite, sand, iron ore powder, calcium sulfate, fruit shell, sand, tree fiber, and galena.

4. The organic consolidating material for plugging leaks in oil-based drilling fluid according to claim 1 or 3, characterized in that: The particle size of the proppant is 20 mesh to 300 mesh.

5. A construction method using the organic consolidating material for plugging leaks in oil-based drilling fluids as claimed in any one of claims 1 to 4, comprising the following steps: S1. Evenly mix epoxy resin, curing agent, curing time regulator, diluent and proppant using a cement truck or a mud batching tank to prepare an organic consolidation material for plugging leaks in oil-based drilling fluid; S2, injecting the organic consolidation material for plugging oil-based drilling fluid prepared in step S1 into the designated construction point within 5 hours, and pressurizing it into the formation; S3. Shut down the well and wait for 8 to 24 hours for solidification. After the well is opened and drilled, subsequent construction work can be carried out.

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