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Non-uniform etching acid liquid system and dolomite reservoir acid fracturing non-uniform etching method

A non-uniform, acid technology, applied in chemical instruments and methods, production fluids, earthwork drilling, etc., can solve problems such as poor stimulation effect of dolomite reservoirs, achieve simple raw materials and formulations, strong conductivity, corrosion resistance, etc. low rate effect

Pending Publication Date: 2022-02-01
PETROCHINA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Compared with limestone reservoirs, when limestone and dolomite reservoirs with similar reservoir conditions are subjected to the same scale of acid fracturing, the stimulation effect of dolomite reservoirs is often poor

Method used

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  • Non-uniform etching acid liquid system and dolomite reservoir acid fracturing non-uniform etching method
  • Non-uniform etching acid liquid system and dolomite reservoir acid fracturing non-uniform etching method
  • Non-uniform etching acid liquid system and dolomite reservoir acid fracturing non-uniform etching method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0060] This embodiment provides a non-uniform etching acid solution system, wherein the non-uniform etching acid solution system includes a hydrochloric acid solution and a thickened acid formed from hydrochloric acid and a thickening agent;

[0061] Taking the total weight of the hydrochloric acid solution as 100%, the concentration of hydrochloric acid is 20wt%, the concentration of Mannich base corrosion inhibitor is 3wt%, the concentration of citric acid is 1wt%, and the concentration of drainage aid is 0.5wt%; for water;

[0062] Based on the total weight of the thickening acid as 100%, the concentration of hydrochloric acid is 20wt%, the concentration of the thickener polyacrylamide is 0.2wt%, the concentration of Mannich base corrosion inhibitor is 3wt%, and the concentration of citric acid is 1wt%. %, the concentration of the drainage aid is 0.5wt%, and the balance is water;

[0063] Based on the total weight of the Mannich base corrosion inhibitor as 100%, it consist...

Embodiment 2

[0066] This embodiment provides a non-uniform etching acid solution system, wherein the non-uniform etching acid solution system includes a hydrochloric acid solution and a thickened acid formed from hydrochloric acid and a thickening agent;

[0067] Taking the total weight of the hydrochloric acid solution as 100%, the concentration of hydrochloric acid is 10wt%, the concentration of Mannich base corrosion inhibitor is 1wt%, the concentration of citric acid is 0.5wt%, and the concentration of drainage aid is 1wt%. for water;

[0068] Based on the total weight of the thickened acid as 100%, the concentration of hydrochloric acid is 10wt%, the concentration of the thickener polyacrylamide is 0.5wt%, the concentration of Mannich base corrosion inhibitor is 1wt%, and the concentration of citric acid is 0.5wt%. wt%, the concentration of the drainage aid is 1wt%, and the balance is water;

[0069] Based on the total weight of the Mannich base corrosion inhibitor as 100%, it consis...

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Abstract

The invention provides a non-uniform etching acid liquid system and a dolomite reservoir acid fracturing non-uniform etching method. The non-uniform etching acid liquid system comprises a hydrochloric acid solution and a thickening acid formed by hydrochloric acid and a thickening agent; based on the total weight of the hydrochloric acid solution being 100%, the concentration of hydrochloric acid is 5-25 wt%, and the balance is water; wherein the concentration of the hydrochloric acid is 5-25 wt%, the concentration of the thickening agent is 0.01-3 wt%, and the balance is water based on the total weight of the thickening acid being 100%. The non-uniform etching acid liquid system provided by the invention is low in corrosion rate, simple in raw materials and formula, economical and environment-friendly. According to the present invention, the thickening acid and the hydrochloric acid solution contained in the non-uniform etching acid liquid system are alternately injected into the dolomite reservoir according to the ratio, such that the coordinated compounding effect can be generated, the non-uniform etching acid liquid has strong acid etching fracture forming ability (the wide and long acid etching fracture can be well formed) on the dolomite reservoir, and the formed fracture has strong flow conductivity.

Description

technical field [0001] The invention relates to a non-uniform etching acid solution system and a method for acid-pressing non-uniform etching of dolomite reservoirs, belonging to the technical field of oil and gas field development. Background technique [0002] Acid fracturing is the main production stimulation measure for carbonate rock reservoirs. The method is to use acid liquid to open fractures in the formation to form acid-etched fractures with a certain conductivity, so as to communicate the wellbore and the reservoir and improve the productivity of oil and gas wells. At present, the acid system used in acid fracturing of carbonate rock reservoirs is developed based on reservoirs with limestone components above 95%. When the rock component dolomite content in the reservoir exceeds 75%, conventional limestone is used Reservoir acid fracturing fluid has poor stimulation effect. From the perspective of acid rock reaction mechanism, limestone reservoirs and dolomite res...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K8/74E21B43/26E21B43/22
CPCC09K8/74E21B43/26E21B43/16
Inventor 晏军齐宁赫安乐徐志鹏崔明月陈国彬梁冲潘林李艺恬
Owner PETROCHINA CO LTD