Even acid distribution method for acidification of heterogeneous storage layer

A heterogeneous reservoir and uniform technology, applied in the direction of earthwork drilling, production fluid, wellbore/well components, etc., can solve the problems of frequent accidents, high cost, and laborious, etc., to improve permeability, avoid time-consuming, avoid The effect of large acid leakage

Inactive Publication Date: 2016-03-16
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The use of layered acidification is not only time-consuming, laborious and costly, but also requires some on-site devices and special equipment, and is prone to frequent accidents

Method used

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  • Even acid distribution method for acidification of heterogeneous storage layer

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] The method proceeds as follows:

[0018] a. After running the acidizing string in the wellbore to the bottom of oil layer 1, circulate the high-permeability layer acidizing fluid containing flocculent temporary plugging materials to the middle of oil layer 2, then close the casing gate 7, and continue injecting into oil layers 1 and 2 ; The fluid for acidizing the hyperpermeable layer containing flocculent temporary plugging material is to take 0.8m according to the oil layer 1,2 per meter 3 For emulsified acid, add 0.5 tons of temporary plugging agent per meter of plugging layer into the emulsified acid, and mix well to obtain the acidification solution for hyperpermeable layer containing flocculent temporary plugging material;

[0019] b. When the pump pressure rises by 3MPa, control the displacement of the pump truck and inject 2.2m of emulsified acid required for acidification of the low-permeability layer according to 1 and 2 per meter of oil layer 3 ;

[0020] c...

Embodiment 2

[0024] The method proceeds as follows:

[0025] a. After running the acidizing string in the wellbore to the bottom of oil layer 1, circulate the high-permeability layer acidizing fluid containing flocculent temporary plugging materials to the middle of oil layer 2, then close the casing gate 7, and continue injecting into oil layers 1 and 2 ; The fluid used for acidizing the hyperpermeable layer containing flocculent temporary plugging material is to take 1.2m according to the oil layer 1,2 per meter 3 For emulsified acid, add 0.3 tons of temporary plugging agent per meter of plugging layer into the emulsified acid, and mix well to obtain the acidification solution for hyperpermeable layer containing flocculent temporary plugging material;

[0026] b. When the pump pressure rises by 5MPa, control the displacement of the pump truck and inject 1.8m of emulsified acid required for acidification of the low-permeability layer according to 1 and 2 per meter of oil layer 3 ;

[00...

Embodiment 4

[0038] Micellar acid is used to replace emulsifying acid, and the others are the same as in Examples 1-3.

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Abstract

The invention provides an even acid distribution method for acidification of a heterogeneous storage layer. The method comprises the following steps that a, after an acidification tubular column is tripped into a an oil layer bottom boundary in a well hole, high-permeation layer acidification liquid containing flocculent temporary plug materials is circulated to the middle portion of an oil layer, then a casing pipe gate is closed, the high-permeation layer acidification liquid is continuously injected into the oil layer, and the high-permeation layer acidification liquid containing the flocculent temporary plug materials is obtained by taking 0.8-1.2 m<3> of acid liquid from every meter of oil layer, adding 0.3-0.5 ton of temporary plug agent in the acid liquid on every meter of plug layer and then carrying out even mixing; b, when the pump pressure rises by 3-5 MPa, the pump car displacement is controlled, and 1.8-2.2 m<3> of acid liquid needed by low-permeation layer acidification is injected into every meter of oil layer; c, a pump is shut down for a reaction for 30-60 min; d, an oil pipe gate is opened for spraying, and residual acid is removed; and e, the oil pipe gate is opened, well washing liquid is pumped from the casing pipe gate, and a well drum is cleaned up. The problem that losses of acid liquid in conventional acidification are large is solved, and the acidification effect is effectively improved. Meanwhile, no special device or equipment is needed, and the defects that layering acidification wastes time, the cost is high, the process is complex, and accidents are likely to happen are overcome.

Description

Technical field: [0001] The invention relates to a method for acidizing heterogeneous reservoirs, in particular to a method for evenly distributing acid. Background technique: [0002] Acidizing is one of the important measures for oil and gas wells to be put into production and increase production, and water injection wells to remove plugging. Conventional acidizing for heterogeneous reservoirs not only cannot unblock severely damaged layers well, but will increase the difference in vertical permeability. This is mainly due to the fact that the natural trend of flow follows the principle of least resistance. The acid liquid enters the zone with the highest permeability and the least damage first, and little or no acid may enter the low-permeability zone or seriously damaged layer that needs plugging removal. The use of layered acidification is not only time-consuming, labor-intensive, and expensive, but also requires some on-site devices and special equipment, and is pron...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): E21B43/22
Inventor 党娟华陈利霞宋志东张金秋朱硕沛杨胜利肖驰俊杜宝坛成梅华薛刚张君宋菲
Owner CHINA PETROLEUM & CHEM CORP
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