Liquid CO2 fracturing technology for shale gas well

A shale gas well, CO2 technology, applied in the direction of wellbore/well components, production fluid, earthwork drilling, etc., can solve the problems of large water consumption, environmental hazards, clay mineral expansion, dispersion migration, etc., to reduce environmental pollution Pollution degree, short production cycle, good practical effect

Active Publication Date: 2015-03-04
RES INST OF SHAANXI YANCHANG PETROLEUM GRP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, for the large-scale slickwater fracturing process of shale gas wells, on the one hand, it needs to consume a large amount of water resources, and at the same time, the fracturing fluid that flows back after fracturing needs to be purified, which is potentially harmful to the environment; on the other hand, shale gas reservoirs Contains a large amount of clay minerals, especially in continental shale gas reservoirs, the clay mineral content even exceeds 60%. When a large amount of water enters the reservoir, it will cause the clay minerals to expand, disperse and migrate, resulting in a decrease in permeability and blockage of pores. Affect the final effect of production increase transformation

Method used

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  • Liquid CO2 fracturing technology for shale gas well

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Shale gas well liquid CO 2 Fracturing process, it needs to be equipped with fracturing pump truck, closed sand mixing truck, CO 2 Booster pump truck, instrument truck, fracturing manifold truck, CO 2 Tanker and CO 2 For storage tanks, the fracturing manifold truck is equipped with low-pressure manifolds and high-pressure manifolds, and the instrument truck is equipped with monitoring instruments, which is characterized in that: the method is carried out according to the following steps:

[0035] Step 1, put some CO 2 Tanker and CO 2 Storage tanks are connected in parallel, and then sequentially connected with CO 2 The booster pump truck, the closed sand mixer truck, and the fracturing pump truck are connected, the fracturing pump truck is connected to the discharge pipeline at the wellhead, and the instrument truck is connected to the above-mentioned vehicles to monitor the working status; all vehicles pass through the fracturing manifold The low-pressure manifold ...

Embodiment 2

[0044] Taking Well X of Yanye as an example, the target interval is 1136 to 1201 meters deep, and the interval is the black shale of the Chang 7 member. The mud logging gas logging shows obvious, and there is no productivity after perforation.

[0045] The well uses liquid CO 2 No sand is used for fracturing, and the fracturing string is a 5.5-inch casing of J55 steel grade.

[0046]Before fracturing, mix 3.0 to 10.0% HCl, 0.5% drainage aid, 0.3% corrosion inhibitor, 0.2% iron ion stabilizer and the balance with water to prepare pre-acid treatment solution 10.0m 3 , the above ratio units are by weight. (The above raw materials are sold in the market)

[0047] Here, signal EL-11 is used as the drainage aid, N-553 as the corrosion inhibitor, and IRON-2066A as the iron ion stabilizer.

[0048] The fracturing construction is carried out according to the following steps:

[0049] Step 1, such as figure 1 As shown, prepare 4 SS2000 fracturing pump trucks, 1 closed sand mixing t...

Embodiment 3

[0057] Taking Well Yanye Y as an example, the target interval is 1,370 to 1,420 meters, and the interval is black shale in the Chang 7 Member. The mud logging gas logging shows obvious, and there is no productivity after perforation.

[0058] The well was completed with J55 steel grade 5.5-inch casing and liquid CO 2 Sand fracturing.

[0059] Preparation of pre-acid treatment fluid before fracturing 10.0m 3 , the formula is 6.0% HCl, 0.5% drainage aid, 0.3% corrosion inhibitor and 0.2% iron ion stabilizer, the balance is water, and the units of the above ratios are all by weight. (The above raw materials are sold in the market)

[0060] The fracturing construction is carried out according to the following steps:

[0061] Step 1, prepare 6 SS2000 fracturing pump trucks, 1 closed sand mixing pump truck, 1 closed sand mixing truck (volume 5m 3 ), 2 CO 2 Booster pump truck (single maximum displacement 4m 3 / min), 1 instrument car, 1 pressure manifold car, 10 CO 2 Tank car (...

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Abstract

The invention relates to the technical field of shale gas exploitation, in particular to a liquid CO2 fracturing technology for a shale gas well. When the liquid CO2 fracturing technology is constructed, a fracturing pump truck, a sealed fracturing blender truck, a CO2 boosting pump truck, a measuring truck, a fracturing pipeline truck, a CO2 tank vehicle and a CO2 storage tank need to be arranged; the fracturing pipeline truck is provided with a pressure manifold and a high pressure manifold; and the measuring truck is provided with a monitoring instrument. The liquid CO2 fracturing technology is characterized in that the liquid CO2 fracturing technology is executed according to six steps of placing fracturing equipment and construction vehicles, testing the pressure, processing pre-acid, constructing liquid CO2 fracturing, closing the well after carrying out fracturing and opening the well for gushing and carrying out flowback after carrying out fracturing. The liquid CO2 fracturing technology for the shale gas well implements high flowback speed and short operation period and basically has harmlessness to a shale gas reservoir stratum.

Description

technical field [0001] The invention relates to the technical field of shale gas exploitation, and is a shale gas well liquid CO 2 Fracturing process. Background technique [0002] Shale gas refers to the natural gas that mainly exists in the interlayers of dark mudstone, high-carbon mudstone, shale and silty rock in an adsorbed or free state. Different from conventional natural gas reservoirs, shale is not only the source rock for natural gas generation, but also the reservoir and caprock for accumulating and preserving natural gas. Due to the characteristics of low porosity and ultra-low permeability, almost all shale gas wells require fracturing to be exploited. At present, shale gas wells mainly use large-scale slickwater fracturing technology. The slickwater fracturing fluid used is mainly composed of clear water, clay stabilizer, surfactant, bactericide, drag reducer, etc., and the water consumption for single-stage fracturing is 2,000 cubic meters Above, for multi-...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): E21B43/267
Inventor 王香增高瑞民吴金桥梁小兵张军涛高志亮申峰
Owner RES INST OF SHAANXI YANCHANG PETROLEUM GRP
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