CN104099074A - Volume fracturing reconstruction crack plugging agent and water plugging construction method - Google Patents
Volume fracturing reconstruction crack plugging agent and water plugging construction method Download PDFInfo
- Publication number
- CN104099074A CN104099074A CN201410254211.8A CN201410254211A CN104099074A CN 104099074 A CN104099074 A CN 104099074A CN 201410254211 A CN201410254211 A CN 201410254211A CN 104099074 A CN104099074 A CN 104099074A
- Authority
- CN
- China
- Prior art keywords
- plugging agent
- volume fracturing
- water
- crack
- agent
- 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.)
- Granted
Links
- 239000003795 chemical substances by application Substances 0.000 title claims abstract description 130
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 65
- 238000010276 construction Methods 0.000 title claims abstract description 30
- 229920001971 elastomer Polymers 0.000 claims abstract description 34
- 239000005060 rubber Substances 0.000 claims abstract description 34
- 239000012530 fluid Substances 0.000 claims abstract description 31
- 239000002245 particle Substances 0.000 claims abstract description 31
- 239000011347 resin Substances 0.000 claims abstract description 22
- 229920005989 resin Polymers 0.000 claims abstract description 22
- 239000003999 initiator Substances 0.000 claims abstract description 20
- 239000007788 liquid Substances 0.000 claims abstract description 17
- 239000002904 solvent Substances 0.000 claims abstract description 16
- 239000002105 nanoparticle Substances 0.000 claims abstract description 14
- 125000006850 spacer group Chemical group 0.000 claims abstract description 11
- 239000000835 fiber Substances 0.000 claims abstract description 7
- 230000009466 transformation Effects 0.000 claims description 48
- 239000000203 mixture Substances 0.000 claims description 28
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 25
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 25
- BTBUEUYNUDRHOZ-UHFFFAOYSA-N Borate Chemical compound [O-]B([O-])[O-] BTBUEUYNUDRHOZ-UHFFFAOYSA-N 0.000 claims description 20
- 239000004971 Cross linker Substances 0.000 claims description 20
- 239000000654 additive Substances 0.000 claims description 20
- 230000000996 additive effect Effects 0.000 claims description 20
- 239000004927 clay Substances 0.000 claims description 20
- 239000003381 stabilizer Substances 0.000 claims description 20
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 claims description 16
- VTYYLEPIZMXCLO-UHFFFAOYSA-L calcium carbonate Substances [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 claims description 11
- 229910000019 calcium carbonate Inorganic materials 0.000 claims description 11
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 claims description 10
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 10
- 238000005553 drilling Methods 0.000 claims description 10
- 238000011160 research Methods 0.000 claims description 10
- 239000005062 Polybutadiene Substances 0.000 claims description 9
- 229920002857 polybutadiene Polymers 0.000 claims description 9
- 239000004744 fabric Substances 0.000 claims description 8
- 238000002347 injection Methods 0.000 claims description 8
- 239000007924 injection Substances 0.000 claims description 8
- 238000003756 stirring Methods 0.000 claims description 6
- KOMNUTZXSVSERR-UHFFFAOYSA-N 1,3,5-tris(prop-2-enyl)-1,3,5-triazinane-2,4,6-trione Chemical group C=CCN1C(=O)N(CC=C)C(=O)N(CC=C)C1=O KOMNUTZXSVSERR-UHFFFAOYSA-N 0.000 claims description 5
- JDXXTKLHHZMVIO-UHFFFAOYSA-N 2-(3-hydroxypropyl)guanidine Chemical compound NC(=N)NCCCO JDXXTKLHHZMVIO-UHFFFAOYSA-N 0.000 claims description 5
- 235000019270 ammonium chloride Nutrition 0.000 claims description 5
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 claims description 5
- 229910001651 emery Inorganic materials 0.000 claims description 5
- 239000003292 glue Substances 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 5
- 238000002156 mixing Methods 0.000 claims description 5
- RTBFRGCFXZNCOE-UHFFFAOYSA-N 1-methylsulfonylpiperidin-4-one Chemical compound CS(=O)(=O)N1CCC(=O)CC1 RTBFRGCFXZNCOE-UHFFFAOYSA-N 0.000 claims description 4
- JFCQEDHGNNZCLN-UHFFFAOYSA-N anhydrous glutaric acid Natural products OC(=O)CCCC(O)=O JFCQEDHGNNZCLN-UHFFFAOYSA-N 0.000 claims description 4
- ADKBGLXGTKOWIU-UHFFFAOYSA-N butanediperoxoic acid Chemical compound OOC(=O)CCC(=O)OO ADKBGLXGTKOWIU-UHFFFAOYSA-N 0.000 claims description 4
- 125000002887 hydroxy group Chemical group [H]O* 0.000 claims description 4
- 150000002978 peroxides Chemical class 0.000 claims description 4
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 claims description 3
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 claims description 2
- 206010017076 Fracture Diseases 0.000 abstract description 19
- 208000010392 Bone Fractures Diseases 0.000 abstract description 18
- 238000011084 recovery Methods 0.000 abstract description 12
- 238000011161 development Methods 0.000 abstract description 5
- 230000018109 developmental process Effects 0.000 abstract description 5
- 238000004519 manufacturing process Methods 0.000 abstract description 5
- 238000006073 displacement reaction Methods 0.000 abstract description 4
- 230000032683 aging Effects 0.000 abstract description 3
- 239000003431 cross linking reagent Substances 0.000 abstract description 2
- 230000007423 decrease Effects 0.000 abstract 1
- 230000002708 enhancing effect Effects 0.000 abstract 1
- 238000000034 method Methods 0.000 description 9
- 238000009472 formulation Methods 0.000 description 8
- 239000000178 monomer Substances 0.000 description 8
- 229920000642 polymer Polymers 0.000 description 8
- 239000000853 adhesive Substances 0.000 description 7
- 230000001070 adhesive effect Effects 0.000 description 7
- 239000012046 mixed solvent Substances 0.000 description 6
- 239000004576 sand Substances 0.000 description 6
- 239000008398 formation water Substances 0.000 description 5
- 239000000047 product Substances 0.000 description 5
- 238000013461 design Methods 0.000 description 4
- 238000006116 polymerization reaction Methods 0.000 description 4
- -1 85.75~88.15 parts Substances 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000011049 filling Methods 0.000 description 3
- 239000000543 intermediate Substances 0.000 description 3
- 230000035699 permeability Effects 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000003750 conditioning effect Effects 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000003912 environmental pollution Methods 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000011435 rock Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 235000020681 well water Nutrition 0.000 description 1
- 239000002349 well water Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/50—Compositions for plastering borehole walls, i.e. compositions for temporary consolidation of borehole walls
- C09K8/504—Compositions based on water or polar solvents
- C09K8/506—Compositions based on water or polar solvents containing organic compounds
- C09K8/508—Compositions based on water or polar solvents containing organic compounds macromolecular compounds
- C09K8/512—Compositions based on water or polar solvents containing organic compounds macromolecular compounds containing cross-linking agents
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K2208/00—Aspects relating to compositions of drilling or well treatment fluids
- C09K2208/08—Fiber-containing well treatment fluids
Landscapes
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Sealing Material Composition (AREA)
- Revetment (AREA)
Abstract
The invention discloses a volume fracturing reconstruction crack plugging agent and a water plugging construction method. The water plugging agent comprises the following components by weight: 40-60% of liquid rubber, 20-30% of a solvent, 5-15% of nano-particles, 5-15% of expandable resin particles, 1-3% of a crosslinking agent, 0.1-1% of an initiator and 0.01-0.2% of fiber. The construction method includes: 1) preparing the plugging agent; 2) injecting the plugging agent into the stratum at a displacement of 100-300L/min; 3) injecting a spacer fluid slug and a gel breaker into the stratum; and 4) conducting clear water displacement, and enhancing the construction displacement to 500-700L/min, and then closing the wellhead for 24h. The construction method is convenient and fast, reduces the shortcomings of large plugging agent consumption and plugging agent shrinking aging failure caused by network fracture development after volume fracturing reconstruction, enlarges the application temperature range of a water plugging reservoir, prolongs the water plugging validity period of the production well, decreases the water content of the production well at the later stage of volume fracturing, and increases the recovery rate of the reservoir.
Description
Technical field
The invention belongs to technical field of petroleum extraction, relate to a kind of volume fracturing transformation crack plugging agent, also relate to the constructional method of this plugging agent in the water blockoff of volume fracturing transformation crack, be particularly useful for the workover treatment in fracturing reform later stage in oil production.
Background technology
Volume fracturing is, by waterfrac treatment, reservoir is implemented to transformation, in forming one or more of major fractures, make constantly expansion and brittle rock generation shearing slip of natural fracture, realize the communication to natural fracture, rock bedding, and force to form secondary fracture in the side direction of major fracture, and on secondary fracture, continue branch's formation secondary secondary fracture, by that analogy, form the interlaced network of fracture of natural fracture and man-made fracture.Thereby the Effective Reservoirs that can carry out seepage flow is smashed, and realizes the modernization overlay of length three-dimensional, increase seepage area and flow conductivity, improve initial flow and ultimate recovery factor.
At present, volume fracturing has become a kind of emphasis Extension Model of the conventional straight well of low permeability oil field and horizontal well volume increase transformation operation.Because low permeability oil field has been implemented waterflooding, through conventional straight well moisture easily sharply rising after water filling is imitated in volume fracturing generation network crack, even " water logging ", after after horizontal well volume fracturing, a certain section of water filling imitated, injected water can prolong network crack and enter fast horizontal section, oil offtake is fallen sharply, overall Water-Content Rise or " water logging ".Recovery well is improved initial flow advantage through volume fracturing transformation than conventional fracturing reform, but has higher " water logging " risk.
Patent documentation CN 102102012A(is on June 23rd, 2011 in open day) a kind of selective plugging agent for horizontal well and preparation method thereof disclosed.In described plugging agent, each ingredients weight parts is: 6.50～7.50 parts of polymer monomers, 4.50～5.75 parts of table active intermediates, 0.85～1.00 part of conditioning agent, 85.75～88.15 parts, water.The preparation method of described plugging agent comprises: table active intermediate is added to the water, then adds polymer monomer, be stirred to evenly; After active intermediate to be shown and polymer monomer reaction, add conditioning agent then stirring reaction; Reaction product is dried, be ground into particle, screening obtains selective plugging agent for horizontal well particle.The beneficial effect of described plugging agent is: there is stronger oil, water selectivity, and synthetic convenient for production, stable chemical performance, strong adaptability, construction technology is simple; Meanwhile, can also improve the sweep efficiency of high moisture maturing field horizontal well development, expand swept volume, improve oil recovery.
The subject matter that the method for the employing polymer monomer water blockoff taking above-mentioned patent documentation as representative exists is summarised as: 1, because volume fracturing generation network crack is large compared with conventional space, especially after horizontal well produces water, shaft bottom discharge pressure is high, polymer monomer plugging agent intensity after polymerization is less, in network crack, adsorb by plugging agent adhesive power, after local water soaks, adhesive power reduces, easily stifled incessantly network crack water exit.2, plugging agent can polymerization shrinkage after polymerization for polymer monomer, produces gap, crack, reduces water plugging effect, and in the long-time hot environment of plugging agent, easily degraded was lost efficacy simultaneously, shortens water blockoff working lipe.3, polymer monomer and metal crosslinking agent all have certain toxicity, are unfavorable for site operation and working fluid environmental protection requirement.4, polymer monomer plugging agent after polymerization has temperature use range restriction (highest temperature and lowest temperature).
Summary of the invention
The present invention is directed to the defect that above-mentioned prior art exists, a kind of volume fracturing transformation crack plugging agent is provided and has applied this plugging agent the constructional method that realizes volume fracturing transformation crack water blockoff.For volume fracturing transformation network crack, the plugging agent and the constructional method that adopt present method to provide, without considering reservoir temperature, formation water salinity, the restriction of network fracture spaces size, can once seal network crack water exit completely, permanently effective, convenient and quick construction, safety and environmental protection, there is certain water blockoff selectivity, can meet the improved water blockoff requirement of recovery well volume fracturing.
The technical scheme that the present invention takes is:
A kind of volume fracturing transformation crack plugging agent, comprise following component, the consisting of of each compositions in weight percentage: fluid rubber 40 ~ 60%, solvent 20 ~ 30%, nano particle 5 ~ 15%, swollen resin particle 5 ~ 15%, linking agent 1 ~ 3%, initiator 0.1 ~ 1% and fiber 0.01 ~ 0.2%.
Preferably, described fluid rubber is any in carboxy terminated polybutadiene fluid rubber, terminal hydroxyl polybutadiene liquid rubber, polyprene fluid rubber.
Preferably, described solvent is any in DMF, N,N-dimethylacetamide, dimethyl sulfoxide (DMSO).
Preferably, described nano particle is nano-calcium carbonate.
Preferably, described swollen resin particle is polyvinyl alcohol swollen resin particle, and the particle size range of this particle is 300～600 orders.
Preferably, described linking agent is iso-cyanuric acid triallyl ester.
Preferably, described initiator is any in peroxysuccinic acid, peroxide of glutaric acid.
Preferably, described fiber is modified polyvinyl alcohol fabric.
Adopt above-mentioned volume fracturing transformation crack plugging agent to carry out water-blocking construction method, comprise the steps, per-cent is all weight percentage described in each step:
1) with truck-mounted blender, 40 ~ 60% fluid rubbers and 20 ~ 30% solvents are sucked in mulling pond, stir emery wheel with truck-mounted blender and add 5 ~ 15% nano particles and 5 ~ 15% swollen resin particles, add 1 ~ 3% linking agent with truck-mounted blender proportioning pump again, in mulling pond, manually add 0.1 ~ 1% initiator and 0.01 ~ 0.2% fiber, by even mixing of materials described in this step, obtain plugging agent;
2) plugging agent that adopts truck-mounted blender prepared by step 1) is pumped to cementing truck, with 100 ~ 300L/min discharge capacity, plugging agent is injected to stratum through cementing truck;
3) in stratum, inject spacer slug again, the injection rate of described spacer slug is 50 ~ 80% of the total consumption of plugging agent;
4) in stratum, inject 5 ~ 15m again
3gel breaker;
5) finally inject clear water as displacing liquid, and operational discharge capacity is increased to 500 ~ 700L/min, after construction finishes, close well head 24 hours, the injection volume of described displacing liquid is the volume summation that pit shaft oil pipe internal volume and volume fracturing transformation in early stage add 2 times of propping agent quantity.
Preferably, described spacer slug is made up of following component, and each weight percentages of components is: clay stabilizer 0.5 ~ 2%, cleanup additive 0.5 ~ 2%, ammonium chloride 0.5 ~ 2%, hydroxypropyl guanidine that glue 0.3 ~ 0.5%, organic borate cross-linker 0.2 ~ 0.5% and water 93.0-98.0%.
Preferably, described clay stabilizer is G511-NWJ clay stabilizer; Cleanup additive is G517-XZ cleanup additive; Organic borate cross-linker is G501-YJ organic borate cross-linker; Wherein, G511-NWJ clay stabilizer, G517-XZ cleanup additive, G501-YJ organic borate cross-linker are drilling engineering and technological research institute of Chuan Qing drilling project company limited independent research product.
Preferably, described gel breaker is 5 ~ 10% hydrogen peroxide that massfraction is.
Compared with prior art, the invention has the beneficial effects as follows:
1, the volume fracturing transformation crack water-blocking construction method that the present invention adopts, residue environmental pollution after the on-the-spot dosing of minimizing plugging agent, convenient and quick construction, reduce network fracture spaces size limits the requirement of plugging agent consumption simultaneously, there is certain water blockoff selectivity, can meet the improved water blockoff demand of recovery well volume fracturing.
2, the present invention selects the effective constituent of fluid rubber as volume fracturing transformation crack plugging agent, plugging agent use range can be expanded, meet the reservoir of 20 DEG C ~ 150 DEG C, the height of formation water salinity does not affect plugging agent performance, plugging strength maximum under reservoir conditions, water blockoff selectivity is high.
3, in the plugging agent of volume fracturing transformation of the present invention crack, also contain nano particle and swollen resin particle, can promote plugging agent integral formulation strength increase, it is the strongest that shut-off capacity reaches, and do not affect integral formulation expansion character in reservoir network crack simultaneously.
4, in the plugging agent of volume fracturing described in the present invention transformation crack, also contain linking agent and initiator, plugging agent intensity is higher, and expansion character the best regulates crack shutoff by expansions, reduces because adhesive power reduces water blockoff inefficacy prolongation plugging agent action time.
5, in the water-blocking construction method of volume fracturing transformation crack, adopt and inject a certain amount of spacer slug, reduce mobile " fingering " phenomenon of filling liquid, plugging agent is evenly pushed into design requirements point of destination.
6, in the present invention using a certain amount of clear water as displacing liquid, and operational discharge capacity is increased to 500 ~ 700L/min, and can make plugging agent arrive fast the far-end in network crack, water exit is carried out to once shutoff completely, reduce plugging agent consumption, recover this well or this Reservoir Section production output.
Below with reference to embodiment, the present invention is described in further details.
embodiment
Ordos Basin low-permeability oil Tanaka, within 2013, adopt volume fracturing transformation well to exceed 800 wells, in secondary oil recovery, have and occurred the moisture fast rise problem of partial volume fracturing reform well, conventional shutoff method DeGrain.
Cause plugging agent consumption greatly and the shortcoming of plugging agent shrink ageing failure for network fracture development after volume fracturing transformation, the present invention has researched and developed a kind of fluid rubber plugging agent product, regulate crack shutoff by expansion, reduce because adhesive power reduces water blockoff and lost efficacy, extend plugging agent action time.On this basis, the plugging agent that utilization of the present invention is newly developed, a kind of volume fracturing transformation crack water-blocking construction method is provided, by displacement control and multistage injection mode, residue environmental pollution after the on-the-spot dosing of minimizing plugging agent, convenient and quick construction, reduce network fracture spaces size limits the requirement of plugging agent consumption simultaneously, expand plugging agent use temperature scope, there is certain water blockoff selectivity, complete shutoff volume fracturing transformation network crack water exit can be realized once, the improved water blockoff demand of recovery well volume fracturing can be met.
After volume fracturing transformation provided by the invention crack water-blocking construction method can solve volume fracturing transformation effectively, network fracture development causes plugging agent consumption greatly and the problem of plugging agent shrink ageing failure, expand the temperature range of water blockoff reservoir applications, extend the validity period of recovery well water blockoff, reduce the water ratio in recovery well volume fracturing later stage, can improve the recovery ratio of reservoir.The application of this invention has broad prospects, and the application of this invention will further promote the development of volume fracturing technology at low permeability oil field, finally improves the recovery ratio of reservoir in low-permeability oilfields.
Embodiment 1
This example provides a kind of volume fracturing transformation crack plugging agent, as preferably, the consisting of of each compositions in weight percentage: fluid rubber 40%, solvent 26.8%, nano particle 15%, polyvinyl alcohol (PVA) swollen resin particle 15%, linking agent 2%, initiator 1% and modified polyvinyl alcohol fabric 0.2%.
Wherein, described fluid rubber is the mixture that contains two kinds of components, and by weight percentage, two kinds of components are 40% carboxy terminated polybutadiene fluid rubber and 60% terminal hydroxyl polybutadiene liquid rubber.One of main component using fluid rubber as plugging agent, the use range of plugging agent can be expanded, meet the construction requirement of differing temps reservoir, and the height of formation water salinity not affect plugging agent performance, under reservoir conditions, plugging strength is larger, and water blockoff selectivity is high.
Wherein, described solvent is mixed solvent, and mixed solvent is the mixture of N,N-dimethylacetamide and dimethyl sulfoxide (DMSO).Wherein, every kind of component is 50% by weight percentage.
Wherein, described nano particle is nano-calcium carbonate.The particle diameter of described PVA swollen resin particle is 600 orders.Adding of nano-calcium carbonate and PVA swollen resin particle, can increase plugging agent integral formulation intensity, improves the shut-off capacity of plugging agent, does not affect integral formulation expansion character in reservoir network crack simultaneously.
Wherein, described linking agent is iso-cyanuric acid triallyl ester.Described initiator is that massfraction is 7% the peroxysuccinic acid aqueous solution.The use of linking agent and initiator, can make the intensity of plugging agent higher, and expansion character is better, regulates crack shutoff by expansion, reduces because adhesive power reduces water blockoff and loses efficacy, and extends plugging agent action time.
Further, adopt above-mentioned volume fracturing transformation crack plugging agent to carry out plug water construction, constructional method comprises the steps, per-cent is all weight percentage described in each step:
1) with truck-mounted blender, 40% fluid rubber and 26.8% solvent are sucked in mulling pond, stir emery wheel with truck-mounted blender and add 15% nano-calcium carbonate and 15%PVA swollen resin particle, add 2% linking agent with truck-mounted blender proportioning pump again, in mulling pond, manually add 1% initiator and 0.2% modified polyvinyl alcohol fabric, by even mixing of materials described in this step, obtain plugging agent;
2) plugging agent that adopts truck-mounted blender prepared by step 1) is pumped to cementing truck, with 100L/min discharge capacity, plugging agent is injected to stratum through cementing truck;
3) in stratum, inject 30m again
3spacer slug (the total consumption of plugging agent 50%).Described spacer slug is 0.5% clay stabilizer, 0.5% cleanup additive, 1% ammonium chloride by weight percentage, 0.3% hydroxypropyl guanidine that glue, the mixture of 0.3% organic borate cross-linker and 97.4% water composition.In this step, clay stabilizer is G511-NWJ clay stabilizer; Cleanup additive is G517-XZ cleanup additive; Organic borate cross-linker is G501-YJ organic borate cross-linker; Wherein, G511-NWJ clay stabilizer, G517-XZ cleanup additive, G501-YJ organic borate cross-linker are drilling engineering and technological research institute of Chuan Qing drilling project company limited independent research product.
4) in stratum, inject 10m again
3gel breaker; Described gel breaker is the mixture of 6% hydrogen peroxide and 94% water by weight percentage.
5) finally inject 112m
3as displacing liquid, (the injection volume of described displacing liquid is the summation that pit shaft oil pipe internal volume and volume fracturing transformation in early stage add the volume of 2 times of propping agent quantity to clear water, because every a bite volume fracturing well adds the scale difference that sand is transformed, fracture spaces is also different accordingly, so will design according to concrete well situation, add sand amount 50 sides to set volume fracturing in earlier stage, well depth 3000m calculates), and operational discharge capacity is increased to 700L/min, after construction finishes, close well head 24 hours, can realize the once shutoff completely of volume fracturing transformation network crack water exit.
Embodiment 2
This example provides a kind of volume fracturing transformation crack plugging agent, as preferably, the consisting of of each compositions in weight percentage: fluid rubber 60%, solvent 20%, nano particle 8%, polyvinyl alcohol (PVA) swollen resin particle 8%, linking agent 3%, initiator 0.9% and modified polyvinyl alcohol fabric 0.1%.
Wherein, described fluid rubber is the mixture that contains two kinds of components, and by weight percentage, two kinds of components are 20% carboxy terminated polybutadiene fluid rubber and 80% polyprene fluid rubber.One of main component using fluid rubber as plugging agent, the use range of plugging agent can be expanded, meet the construction requirement of differing temps reservoir, and the height of formation water salinity not affect plugging agent performance, under reservoir conditions, plugging strength is larger, and water blockoff selectivity is high.
Wherein, described solvent is mixed solvent, by weight percentage, mixed solvent consist of 30%N, dinethylformamide and 70%N, N-N,N-DIMETHYLACETAMIDE.
Wherein, described nano particle is nano-calcium carbonate.The particle diameter of described PVA swollen resin particle is 500 orders.Adding of nano-calcium carbonate and PVA swollen resin particle, can increase plugging agent integral formulation intensity, improves the shut-off capacity of plugging agent, does not affect integral formulation expansion character in reservoir network crack simultaneously.
Wherein, described linking agent is iso-cyanuric acid triallyl ester.Described initiator is that massfraction is 7% the peroxide of glutaric acid aqueous solution.The use of linking agent and initiator, can make the intensity of plugging agent higher, and expansion character is better, regulates crack shutoff by expansion, reduces because adhesive power reduces water blockoff and loses efficacy, and extends plugging agent action time.
Further, adopt above-mentioned volume fracturing transformation crack plugging agent to carry out plug water construction, constructional method comprises the steps, per-cent is all weight percentage described in each step:
1) with truck-mounted blender, 60% fluid rubber and 20% solvent are sucked in mulling pond, stir emery wheel with truck-mounted blender and add 8% nano-calcium carbonate and 8%PVA swollen resin particle, add 3% linking agent with truck-mounted blender proportioning pump again, in mulling pond, manually add 0.9% initiator and 0.1% modified polyvinyl alcohol fabric, by even mixing of materials described in this step, obtain plugging agent;
2) plugging agent that adopts truck-mounted blender prepared by step 1) is pumped to cementing truck, with 300L/min discharge capacity, plugging agent is injected to stratum through cementing truck;
3) in stratum, inject 40m again
3spacer slug (the total consumption of plugging agent 80%).Described spacer slug is 0.8% clay stabilizer, 0.8% cleanup additive, 2% ammonium chloride by weight percentage, 0.5% hydroxypropyl guanidine that glue, the mixture of 0.5% organic borate cross-linker and 95.4% water composition.In this step, clay stabilizer is G511-NWJ clay stabilizer; Cleanup additive is G517-XZ cleanup additive; Organic borate cross-linker is G501-YJ organic borate cross-linker; Wherein, G511-NWJ clay stabilizer, G517-XZ cleanup additive, G501-YJ organic borate cross-linker are drilling engineering and technological research institute of Chuan Qing drilling project company limited independent research product.
4) in stratum, inject 7m again
3gel breaker; Described gel breaker is the mixture of 8% hydrogen peroxide and 92% water by weight percentage.
5) finally inject 166m
3as displacing liquid, (the injection volume of described displacing liquid is the summation that pit shaft oil pipe internal volume and volume fracturing transformation in early stage add the volume of 2 times of propping agent quantity to clear water, because every a bite volume fracturing well adds the scale difference that sand is transformed, fracture spaces is also different accordingly, so will design according to concrete well situation, add sand amount 80 sides to set volume fracturing in earlier stage, well depth 2000m calculates), and operational discharge capacity is increased to 500L/min, after construction finishes, close well head 24 hours, can realize the once shutoff completely of volume fracturing transformation network crack water exit.
Embodiment 3
This example provides a kind of volume fracturing transformation crack plugging agent, as preferably, the consisting of of each compositions in weight percentage: fluid rubber 50%, solvent 25%, nano particle 11%, polyvinyl alcohol (PVA) swollen resin particle 11%, linking agent 2.5%, initiator 0.45% and modified polyvinyl alcohol fabric 0.05%.
Wherein, described fluid rubber is the mixture that contains three kinds of components, and by weight percentage, three kinds of components are 10% carboxy terminated polybutadiene fluid rubber, 80% terminal hydroxyl polybutadiene liquid rubber and 10% polyprene fluid rubber.One of main component using fluid rubber as plugging agent, the use range of plugging agent can be expanded, meet the construction requirement of differing temps reservoir, and the height of formation water salinity not affect plugging agent performance, under reservoir conditions, plugging strength is larger, and water blockoff selectivity is high.
Wherein, described solvent is mixed solvent, by weight percentage, mixed solvent consist of 80%N, N-N,N-DIMETHYLACETAMIDE and 20% dimethyl sulfoxide (DMSO).
Wherein, described nano particle is nano-calcium carbonate.The particle diameter of described PVA swollen resin particle is 500 orders.Adding of nano-calcium carbonate and PVA swollen resin particle, can increase plugging agent integral formulation intensity, improves the shut-off capacity of plugging agent, does not affect integral formulation expansion character in reservoir network crack simultaneously.
Wherein, described linking agent is iso-cyanuric acid triallyl ester.The each compositions in weight percentage of described initiator is the mixture of 6% peroxysuccinic acid, 1% peroxide of glutaric acid and 93% water.The use of linking agent and initiator, can make the intensity of plugging agent higher, and expansion character is better, regulates crack shutoff by expansion, reduces because adhesive power reduces water blockoff and loses efficacy, and extends plugging agent action time.
Further, adopt above-mentioned volume fracturing transformation crack plugging agent to carry out plug water construction, constructional method comprises the steps, per-cent is all weight percentage described in each step:
1) with truck-mounted blender, 50% fluid rubber and 25% solvent are sucked in mulling pond, stir emery wheel with truck-mounted blender and add 11% nano-calcium carbonate and 11%PVA swollen resin particle, add 2.5% linking agent with truck-mounted blender proportioning pump again, in mulling pond, manually add 0.45% initiator and 0.05% modified polyvinyl alcohol fabric, by even mixing of materials described in this step, obtain plugging agent;
2) plugging agent that adopts truck-mounted blender prepared by step 1) is pumped to cementing truck, with 200L/min discharge capacity, plugging agent is injected to stratum through cementing truck;
3) in stratum, inject 38.5m again
3spacer slug (the total consumption of plugging agent 70%).Described spacer slug is 2% clay stabilizer, 1% cleanup additive, 1% ammonium chloride by weight percentage, 0.4% hydroxypropyl guanidine that glue, the mixture of 0.4% organic borate cross-linker and 95.2% water composition.In this step, clay stabilizer is G511-NWJ clay stabilizer; Cleanup additive is G517-XZ cleanup additive; Organic borate cross-linker is G501-YJ organic borate cross-linker; Wherein, G511-NWJ clay stabilizer, G517-XZ cleanup additive, G501-YJ organic borate cross-linker are drilling engineering and technological research institute of Chuan Qing drilling project company limited independent research product.
4) in stratum, inject 15m again
3gel breaker; Described gel breaker is the mixture of 5% hydrogen peroxide and 95% water by weight percentage.
5) finally inject 143m
3as displacing liquid, (the injection volume of described displacing liquid is the summation that pit shaft oil pipe internal volume and volume fracturing transformation in early stage add the volume of 2 times of propping agent quantity to clear water, because every a bite volume fracturing well adds the scale difference that sand is transformed, fracture spaces is also different accordingly, so will design according to concrete well situation, add sand amount 70 sides to set volume fracturing in earlier stage, well depth 1000m calculates), and operational discharge capacity is increased to 600L/min, after construction finishes, close well head 24 hours, can realize the once shutoff completely of volume fracturing transformation network crack water exit.
Above embodiments of the present invention are described, but the present invention is not limited to above-mentioned embodiment, in the ken that one skilled in the relevant art possesses, can also under the prerequisite that does not depart from aim of the present invention, makes a variety of changes.
Claims (12)
1. a volume fracturing transformation crack plugging agent, it is characterized in that comprising following component, the consisting of of each compositions in weight percentage: fluid rubber 40 ~ 60%, solvent 20 ~ 30%, nano particle 5 ~ 15%, swollen resin particle 5 ~ 15%, linking agent 1 ~ 3%, initiator 0.1 ~ 1% and fiber 0.01 ~ 0.2%.
2. volume fracturing transformation according to claim 1 crack plugging agent, is characterized in that: described fluid rubber is any in carboxy terminated polybutadiene fluid rubber, terminal hydroxyl polybutadiene liquid rubber, polyprene fluid rubber.
3. volume fracturing transformation according to claim 1 crack plugging agent, is characterized in that: described solvent is any in DMF, N,N-dimethylacetamide, dimethyl sulfoxide (DMSO).
4. volume fracturing transformation according to claim 1 crack plugging agent, is characterized in that: described nano particle is nano-calcium carbonate.
5. volume fracturing transformation according to claim 1 crack plugging agent, is characterized in that: described swollen resin particle is polyvinyl alcohol swollen resin particle, and the particle size range of this particle is 300～600 orders.
6. volume fracturing transformation according to claim 1 crack plugging agent, is characterized in that: described linking agent is iso-cyanuric acid triallyl ester.
7. volume fracturing transformation according to claim 1 crack plugging agent, is characterized in that: described initiator is any in peroxysuccinic acid, peroxide of glutaric acid.
8. volume fracturing transformation according to claim 1 crack plugging agent, is characterized in that: described fiber is modified polyvinyl alcohol fabric.
9. adopt volume fracturing claimed in claim 1 transformation crack plugging agent to carry out water-blocking construction method, it is characterized in that comprising the steps, per-cent is all weight percentage described in each step:
40 ~ 60% fluid rubbers and 20 ~ 30% solvents are sucked in mulling pond with truck-mounted blender, stir emery wheel with truck-mounted blender and add 5 ~ 15% nano particles and 5 ~ 15% swollen resin particles, add 1 ~ 3% linking agent with truck-mounted blender proportioning pump again, in mulling pond, manually add 0.1 ~ 1% initiator and 0.01 ~ 0.2% fiber, by even mixing of materials described in this step, obtain plugging agent;
The plugging agent that adopts truck-mounted blender prepared by step 1) is pumped to cementing truck, with 100 ~ 300L/min discharge capacity, plugging agent is injected to stratum through cementing truck;
In stratum, inject spacer slug again, the injection rate of described spacer slug is 50 ~ 80% of the total consumption of plugging agent;
In stratum, inject 5 ~ 15m again
3gel breaker;
Finally inject clear water as displacing liquid, and operational discharge capacity is increased to 500 ~ 700L/min, after construction finishes, close well head 24 hours, the injection volume of described displacing liquid is the summation that pit shaft oil pipe internal volume and volume fracturing transformation in early stage add the volume of 2 times of propping agent quantity.
10. volume fracturing transformation according to claim 9 crack water-blocking construction method, it is characterized in that, described spacer slug is made up of following component, and each weight percentages of components is: clay stabilizer 0.5 ~ 2%, cleanup additive 0.5 ~ 2%, ammonium chloride 0.5 ~ 2%, hydroxypropyl guanidine that glue 0.3 ~ 0.5%, organic borate cross-linker 0.2 ~ 0.5% and water 93.0-98.0%.
11. volume fracturing transformation according to claim 10 crack water-blocking construction methods, is characterized in that, described clay stabilizer is G511-NWJ clay stabilizer; Cleanup additive is G517-XZ cleanup additive; Organic borate cross-linker is G501-YJ organic borate cross-linker; Wherein, G511-NWJ clay stabilizer, G517-XZ cleanup additive, G501-YJ organic borate cross-linker are drilling engineering and technological research institute of Chuan Qing drilling project company limited independent research product.
12. volume fracturing transformation according to claim 9 crack water-blocking construction methods, is characterized in that, described gel breaker is 5 ~ 10% hydrogen peroxide that massfraction is.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410254211.8A CN104099074B (en) | 2014-06-10 | 2014-06-10 | Volume fracturing reconstruction crack plugging agent and water plugging construction method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410254211.8A CN104099074B (en) | 2014-06-10 | 2014-06-10 | Volume fracturing reconstruction crack plugging agent and water plugging construction method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104099074A true CN104099074A (en) | 2014-10-15 |
| CN104099074B CN104099074B (en) | 2017-02-15 |
Family
ID=51667626
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410254211.8A Active CN104099074B (en) | 2014-06-10 | 2014-06-10 | Volume fracturing reconstruction crack plugging agent and water plugging construction method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104099074B (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107287669A (en) * | 2016-04-12 | 2017-10-24 | 中国石油化工集团公司 | A kind of alkaline-resisting temperature resistance PVA fibers and application thereof |
| CN107287675A (en) * | 2016-04-12 | 2017-10-24 | 中国石油化工集团公司 | A kind of vinal and preparation method thereof |
| CN104405360B (en) * | 2014-10-27 | 2018-02-27 | 中石化胜利油田分公司采油工艺研究院 | A kind of fracturing process for improving fracturing fluid solid-carrying performance |
| CN109236274A (en) * | 2018-11-01 | 2019-01-18 | 中国石油天然气股份有限公司 | Well selection method for water plugging of high-water-content oil well |
| CN110500080A (en) * | 2019-09-20 | 2019-11-26 | 四川洁能锐思石油技术有限公司 | A kind of high permeability zone bottom water coning shuts down stifled dredge of well and adopts control comprehensive processing method |
| CN110724508A (en) * | 2018-07-16 | 2020-01-24 | 长江大学 | Fiber composite gel particle bridging agent for fractured reservoir and preparation method thereof |
| CN114017017A (en) * | 2021-11-11 | 2022-02-08 | 西南石油大学 | Multi-scale crack plugging condition evaluation and experiment method |
| CN114075431A (en) * | 2020-08-17 | 2022-02-22 | 中石化石油工程技术服务有限公司 | Weak cross-linked polymer for oil-based drilling fluid plugging and preparation method thereof |
| CN115109571A (en) * | 2022-05-23 | 2022-09-27 | 四川捷贝通能源科技有限公司 | Temperature-control phase-change water shutoff agent and preparation method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080028994A1 (en) * | 2006-08-07 | 2008-02-07 | Veronique Barlet-Gouedard | Geopolymer composition and application in oilfield industry |
| CN102557539A (en) * | 2011-12-27 | 2012-07-11 | 天津市宝坻区兴海盛橡胶加工厂 | High-performance rubber concrete |
| WO2012174527A2 (en) * | 2011-06-17 | 2012-12-20 | M-I L.L.C. | Composition of polybutadiene-based formula for downhole applications |
| CN102443383B (en) * | 2011-09-06 | 2013-04-24 | 中国石油天然气集团公司 | High-dehydration hardenable plugging sealing agent |
| CN103756659A (en) * | 2013-12-28 | 2014-04-30 | 北京国海能源技术研究院 | Flexible particle diverter and preparation method thereof |
-
2014
- 2014-06-10 CN CN201410254211.8A patent/CN104099074B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080028994A1 (en) * | 2006-08-07 | 2008-02-07 | Veronique Barlet-Gouedard | Geopolymer composition and application in oilfield industry |
| WO2012174527A2 (en) * | 2011-06-17 | 2012-12-20 | M-I L.L.C. | Composition of polybutadiene-based formula for downhole applications |
| CN103827252A (en) * | 2011-06-17 | 2014-05-28 | M-I有限公司 | Composition of polybutadiene-based formula for downhole applications |
| CN102443383B (en) * | 2011-09-06 | 2013-04-24 | 中国石油天然气集团公司 | High-dehydration hardenable plugging sealing agent |
| CN102557539A (en) * | 2011-12-27 | 2012-07-11 | 天津市宝坻区兴海盛橡胶加工厂 | High-performance rubber concrete |
| CN103756659A (en) * | 2013-12-28 | 2014-04-30 | 北京国海能源技术研究院 | Flexible particle diverter and preparation method thereof |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104405360B (en) * | 2014-10-27 | 2018-02-27 | 中石化胜利油田分公司采油工艺研究院 | A kind of fracturing process for improving fracturing fluid solid-carrying performance |
| CN107287669A (en) * | 2016-04-12 | 2017-10-24 | 中国石油化工集团公司 | A kind of alkaline-resisting temperature resistance PVA fibers and application thereof |
| CN107287675A (en) * | 2016-04-12 | 2017-10-24 | 中国石油化工集团公司 | A kind of vinal and preparation method thereof |
| CN110724508A (en) * | 2018-07-16 | 2020-01-24 | 长江大学 | Fiber composite gel particle bridging agent for fractured reservoir and preparation method thereof |
| CN109236274A (en) * | 2018-11-01 | 2019-01-18 | 中国石油天然气股份有限公司 | Well selection method for water plugging of high-water-content oil well |
| CN110500080A (en) * | 2019-09-20 | 2019-11-26 | 四川洁能锐思石油技术有限公司 | A kind of high permeability zone bottom water coning shuts down stifled dredge of well and adopts control comprehensive processing method |
| CN110500080B (en) * | 2019-09-20 | 2021-09-07 | 四川洁能锐思石油技术有限公司 | High-permeability bottoming water coning shut-in well plugging dredging production control comprehensive treatment method |
| CN114075431A (en) * | 2020-08-17 | 2022-02-22 | 中石化石油工程技术服务有限公司 | Weak cross-linked polymer for oil-based drilling fluid plugging and preparation method thereof |
| CN114075431B (en) * | 2020-08-17 | 2023-10-13 | 中石化石油工程技术服务有限公司 | Weak cross-linked polymer for plugging oil-based drilling fluid and preparation method thereof |
| CN114017017A (en) * | 2021-11-11 | 2022-02-08 | 西南石油大学 | Multi-scale crack plugging condition evaluation and experiment method |
| CN115109571A (en) * | 2022-05-23 | 2022-09-27 | 四川捷贝通能源科技有限公司 | Temperature-control phase-change water shutoff agent and preparation method thereof |
| CN115109571B (en) * | 2022-05-23 | 2023-10-24 | 四川捷贝通能源科技有限公司 | Temperature-control phase-change water shutoff agent and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104099074B (en) | 2017-02-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104099074A (en) | Volume fracturing reconstruction crack plugging agent and water plugging construction method | |
| CN106050213B (en) | A kind of sandstone reservoir low damage distributary acid method | |
| CN104629697B (en) | A kind of heatproof frozen glue | |
| CN102093864B (en) | Temporary plugging diverting agent for repeated fracturing of oil-water well and preparation method thereof | |
| CN102155209B (en) | Method for fracturing stratum by acidity viscoelastic fluid | |
| CN102562012B (en) | Method for improving recovery ratio of water-flooding developed common heavy oil reservoir | |
| CN106188403B (en) | A kind of anti-CO of high temperature and high salt oil deposit2Has channeling blocking agent and preparation method thereof | |
| CN105754569B (en) | Low-permeability oil reservoir water injection well pretreating agent and preparation method thereof | |
| CN102504777B (en) | Delaying cross-linking polymer hard-gel in-depth profile controlling agent and preparation method thereof | |
| CN110484229B (en) | Composite oil displacement system for low-permeability oil reservoir and preparation and application methods thereof | |
| CN111394086B (en) | Preparation method of environment-friendly water-saving fracturing fluid | |
| CN102071919A (en) | Oil-gas well fiber assisted water control fracturing method | |
| CN105888641A (en) | Carbon dioxide-anti-drag water compound fracturing method | |
| CN103184040A (en) | Stratum pre-crosslinked gel water shutoff agent | |
| CN114836184A (en) | Degradable temporary plugging agent for well repair of offshore large-leakage oil-water well and use method thereof | |
| CN105647505A (en) | Solution capable of preparing fracturing fluid by using high-salinity water and application thereof | |
| CA2922848A1 (en) | Carbonate based slurry fracturing using solid acid for unconventional reservoirs | |
| CN109915093A (en) | A kind of method that " stifled/tune/drive " integration improves oil recovery | |
| CN106958438B (en) | A kind of method for removing blockage of polymer flooding blocking well | |
| CN106634927A (en) | Authigenic acid-induced tackifying conrol system with oil washing effect and preparation method | |
| CN103980872A (en) | Environmental-friendly gel plugging agent applicable to low-temperature oil pool and applications of gel plugging agent | |
| CN106833588B (en) | Sulfur-fixing combustion-supporting high-temperature profile control agent and preparation method and application thereof | |
| CN102618232B (en) | Plugging agent for fractured-vuggy oil reservoir | |
| CN112324411A (en) | Loose sandstone heavy oil reservoir vertical well complex long-seam fracturing process | |
| CN108913115B (en) | Low-damage composite fracturing fluid and application method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20201119 Address after: 100007 Dongcheng District, Dongzhimen, China, North Street, No. 9 Oil Mansion, No. Patentee after: CHINA NATIONAL PETROLEUM Corp. Patentee after: CNPC CHUANQING DRILLING ENGINEERING Co.,Ltd. Address before: 710016 Shaanxi city of Xi'an province Weiyang District four road Fengcheng Changqing Technology Building Patentee before: CNPC CHUANQING DRILLING ENGINEERING COMPANY LIMITED ENGINEERING TECHNOLOGY Research Institute |