Method for improving highly argillaceous sandstone layer

A kind of muddy sandstone and reservoir technology, which is applied in the field of downhole operation and transformation of strata, can solve the problems of fracturing design regardless of formation conditions and pressure failure, so as to achieve the effect of increasing single well production, reducing construction pressure and improving stimulation effect

Inactive Publication Date: 2015-07-01
CHINA NAT PETROLEUM CORP CHUANQING DRILLING ENG CO LTD CHANGQING DOWNHOLE TECH CO
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Problems solved by technology

[0002] Hydraulic fracturing is a measure to increase production and injection of oil, gas and water wells. However, at present, the fracturing design of various oilfields still adopts conventional "empirical" pumping procedures regardless of formation conditions.
Since the pre-fluid volume of the conventional "empirical" pumping procedure accounts for about 20% of the sand-carrying fluid volume, the acid treatment fluid does not change according to the physical properties of the formation, resulting in the sandstone formation with high shale content being unable to be opened and only can be waived

Method used

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  • Method for improving highly argillaceous sandstone layer
  • Method for improving highly argillaceous sandstone layer
  • Method for improving highly argillaceous sandstone layer

Examples

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Effect test

Embodiment 1

[0016] Example 1, a method for transforming a high-shale sandstone layer. In the construction process, after sandblasting and perforating, the reservoir is firstly treated with an acid solution, and then the pre-fluid is injected and the sand plug is treated, and then the carrying fluid is injected. The sand liquid finally broke through the formation successfully. The acid solution includes HCL, HF, demulsifier, clay stabilizer, citric acid and corrosion inhibitor, and the mass percentage of each component is 10-12% HCL, 3.0-6.0% HF, 0.5% demulsifier, 0.3% clay stabilizer, 0.1% citric acid and 1.0% corrosion inhibitor, the rest is water.

[0017] In this embodiment, the acid solution is used to pretreat the reservoir in the well before the prefluid is injected, which effectively reduces the construction pressure, finally successfully breaks the formation, and improves the success rate of high-shale sandstone fracturing and the effect of reservoir stimulation.

Embodiment 2

[0018] Example 2. This example is to reform the high-shale sandstone layer of Well GP33-21. The physical property data of the first section of the well at 2368.0 m: the acoustic time difference is 209.75 μs / m, and the shale content is 23.33%.

[0019] During the construction of this example, after the perforation is completed, 20m of acid solution is injected twice. 3 Pretreatment, the mass percentage of each component of the acid solution: 12% HCl, 6.0% HF, 0.5% demulsifier (CF-5C, produced by Xi'an Changqing Chemical Petroleum Group Co., Ltd.), 0.3% clay stabilizer (COP-1 , produced by Xi'an Changqing Chemical Petroleum Group Co., Ltd.), 0.1% citric acid and 1.0% corrosion inhibitor (HJF-94, produced by Xi'an Changqing Chemical Petroleum Group Co., Ltd.), the rest is water, shut down the well for 2 hours. Front liquid volume 220m 3 , the volume ratio of the pre-fluid and the sand-carrying fluid is 120:100, and the sand concentration in the pre-fluid stage is 30kg / m 3 The s...

Embodiment 3

[0020] Example 3, this example is the reconstruction of the high shale sandstone layer in Well HP3-11, the physical property data of the first section of the well at 3176.0 and 3186.0m: the acoustic time difference is 205.57μs / m, and the shale content is 20.3%.

[0021] In the construction process of this embodiment, after the perforation is completed, 20m of acid solution is injected 3 Pretreatment, the mass percentage of each component of the acid solution: 10% HCl, 3.0% HF, 0.5% demulsifier (CF-5C, produced by Xi'an Changqing Chemical Petroleum Group Co., Ltd.), 0.3% clay stabilizer (COP-1 , produced by Xi'an Changqing Chemical Petroleum Group Co., Ltd.), 0.1% citric acid and 1.0% corrosion inhibitor (HJF-94, produced by Xi'an Changqing Chemical Petroleum Group Co., Ltd.), the rest is water, shut down the well for 2 hours. Prefluid volume 216.5m 3 , the volume ratio to the sand-carrying liquid is 100:100, and the sand concentration in the pre-fluid stage is 15-50kg / m 3 Th...

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Abstract

The invention relates to a method for improving a highly argillaceous sandstone layer. Firstly, an acid solution is used for preprocessing a reservoir stratum, then prepad fluid and sand-carrying fluid are injected, and sand plugging processing is carried out, wherein the acid solution comprises, by mass, 10-12% of HCL, 3.0-6.0% of HF, 0.5% of emulsion breaker, 0.3% of clay stabilizer, 0.1% of citric acid, 1.0% of corrosion inhibitor, and the balance water. The acid solution is used for preprocessing the reservoir stratum before the prepad fluid is injected, the construction pressure is effectively reduced, the fracturing success rate of the highly argillaceous sandstone and the reservoir stratum improvement effect are improved, the method has an obvious effect for improving the reservoir stratum of poor physical performance, and the yield of a single well is improved.

Description

technical field [0001] The invention relates to a method for transforming a stratum by downhole operation, in particular to a method for transforming a high-shale sandstone layer. Background technique [0002] Hydraulic fracturing is a measure to increase production and injection of oil, gas and water wells. However, at present, the fracturing design of various oil fields still adopts conventional "empirical" pumping procedures regardless of formation conditions. Since the pre-fluid volume of the conventional "empirical" pumping procedure accounts for about 20% of the sand-carrying fluid volume, the acid treatment fluid does not change according to the physical properties of the formation, resulting in the sandstone formation with high shale content being unable to be opened and only can be waived. Contents of the invention [0003] The purpose of the present invention is to provide a method for reforming high-shale sandstone formations, which is suitable for fracturing o...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): E21B43/267C09K8/80C09K8/74
CPCE21B43/267C09K8/74C09K8/80C09K2208/12C09K2208/32
Inventor 赵伟王祖文韩锐田荣生胡期旭李大维慎思强林涛陈诚闫育东段小军袁理生
Owner CHINA NAT PETROLEUM CORP CHUANQING DRILLING ENG CO LTD CHANGQING DOWNHOLE TECH CO
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