Acid fracturing process of oil gas well mining temperature control various mucic acid

A technology for viscous acid and oil and gas wells, which is applied in the direction of production fluid, chemical instruments and methods, earthwork drilling and production, etc., to achieve the effect of easy pumping and reducing the reaction rate of acid rock

Active Publication Date: 2009-01-28
PETROCHINA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The existing LCA acid liquid system is to add a metal cross-linking agent in the system. The metal cross-linking agent is characterized by cross-linking under the condition of pH value > 2, that is, it can only become viscous under the condition of residual acid. H in acid + The concentration is already very low, so this type of acid system is not an ideal retarding system, it is only a low fluid loss acid system

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] Example 1: An example of acid fracturing with temperature-controlled viscosities

[0043] Tazhong A well is a key exploration well deployed by Tarim Oilfield Company in 2005. A total of 10 barrels of cores were taken from the 5420.0-5483.58m section of the granular limestone section of the well, and the core was 45.94m, including: oil spots 0.75m, oil traces 3.78m, fluorescence 20.73m, and oil-free reservoirs 2.39m. The lithology is brown-gray oil-stained powder limestone, brown-gray oil-stained powder crystal limestone, gray-brown fluorescent powder crystal limestone, brown-gray oil-stained powder crystal limestone, brown-gray fluorescent powder crystal limestone, brown-gray fluorescent algae Limestone, brown-gray micrite, brown-gray fluorescent micrite, brown-gray micrite, brown-gray fluorescent micrite; logging interpretation porosity 0.2-2%, belonging to low porosity and low permeability type, Connectivity is poor. Comprehensive comparison shows that the physical ...

Embodiment 2

[0059] Example 2: An example of closed-acidification process for prefluid temperature-controlled variable visco-acid fracturing

[0060] Well B is a prospecting well of Tarim Oilfield Company. The reconstructed well section 5666.1-5681m is the marl-bearing section of the Lianglitage Formation, and a total of 15m / 4 layers of reservoirs are interpreted, with an average porosity of 2.2% and a fracture porosity of 0.012%.

[0061] The main idea of ​​the reservoir stimulation of this well is to find and connect the fracture or karst cave development zone in the far well zone, so as to obtain high and stable production of industrial oil and gas flow. The reservoir stimulation plan is designed as a pre-fluid temperature-controlled variable viscous acid fracturing + closed acidizing process. First, the pre-fluid jelly is used to press the formation to explore the fracture-cavity development zone, and then use the pre-fluid gel with good slowing performance and strong penetration abili...

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PUM

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Abstract

The invention relates to an acid fracturing method of a temperature-control and variable-viscosity acid in the exploitation of an oil-gas well, which comprises the steps that: a common chlorohydric acid pickling process is firstly used for removing the pollution of an embrasure; then, the temperature-control and variable-viscosity acid fracturing process, or an ahead-fluid temperature-control and variable-viscosity acid fracturing process, or a temperature-control and variable-viscosity acid fracturing enclosed acidizing process, or an ahead-fluid temperature-control and variable-viscosity acid fracturing enclosed acidizing process is adopted; the weight ratio of the components of the temperature-control and variable-viscosity acid are as follows: 100 portions of basic acid solution, 0.5 portion to 1.5 portions of the main agent of the temperature-control and variable-viscosity acid, 1 portion to 3 portions of a corrosion inhibitor of the temperature-control and variable-viscosity acid, 0.5 portion to 1 portion of an emulsion breaker, 0.5 portion to 1 portion of a ferric ion stabilizer and 0.5 portion to 1 portion of a high efficient discharge aiding agent; 2-percent KCL clear water is used for displacing the temperature-control and variable-viscosity acid into the stratum. The temperature-control and variable-viscosity acid is easily prepared on site, with low friction drag and strong pumpability, thereby being capable of being applied to high-discharge construction; under the high temperature condition of a storing layer, both the fresh acid and the residue acid have high viscosity, thus increasing the length of acid-etching cracks. After the construction is finished, the viscosity of the residue acid is reduced, which is beneficial to the back discharge of the residue acid.

Description

technical field [0001] The invention relates to a temperature-controlled variable-viscosity acid-acid fracturing method for controlling the fluid loss of acid fluid in fractures of carbonate rock reservoirs and the reaction rate of acid rock by controlling the viscosity of acid fluid in oil and gas exploitation. Background technique [0002] Acid fracturing technology is one of the effective methods for stimulation of oil and gas wells in carbonate reservoirs. The stimulation effect of acid fracturing in low-permeability carbonate reservoirs mainly depends on the length of acid-etched fractures and the conductivity of fractures. This depends on the performance of the acid system and the acid fracturing process. The acid fracturing process mainly depends on the performance of the equipment, and the performance of the acid system plays a key role. [0003] At present, low-permeability carbonate reservoir stimulation technologies at home and abroad mainly include acid fracturi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): E21B43/27C09K8/72
Inventor 周福建刘玉章张福祥熊春明杨贤友彭建新刘雄飞连胜江李向东陈芳钱春江杨建军
Owner PETROCHINA CO LTD
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