Evaluation method of acid fracturing effect of carbonate rock

An evaluation method and carbonate rock technology, which can be used in earth-moving drilling, production fluids, wellbore/well components, etc., and can solve the problems of strong randomness of acid reaction and difficult to accurately predict the conductivity of acid-etched fractures.

Active Publication Date: 2017-09-22
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
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AI Technical Summary

Problems solved by technology

However, in the actual construction process, due to the strong randomness of acid acid reaction, it is difficult to accurately predict the conductivity of acid-etched fractures, so the evaluation results have certain limitations

Method used

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  • Evaluation method of acid fracturing effect of carbonate rock
  • Evaluation method of acid fracturing effect of carbonate rock
  • Evaluation method of acid fracturing effect of carbonate rock

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] 1. Core sample and acid solution preparation

[0040] The core of the target carbonate rock is cut into several rectangles with semicircular arcs at both ends, and the size is 152.4 cm long x 50.8 cm wide x 25.4 cm thick. The surface of the prepared core sample was photographed and obtained as follows: figure 2 Photos shown. Then, a 3D topography scan was performed with a three-dimensional surface topography instrument ST400, and the arithmetic mean value of the surface roughness of all scanning positions was taken as the average surface roughness Sa of the core sample.

[0041] A certain acid liquid commonly used in an oil field was used as the standard acid liquid, and acid liquids with three formulations of Jiao 2000, Jiao 3000, and Jiao 4000 were selected as the acid liquids to be tested.

[0042] 2. Acid etching

[0043] Coat the contact walls between the core sample and the API diversion chamber with silica gel to prevent the acid from flowing out from both si...

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Abstract

The invention provides an evaluation method of an acid fracturing effect of carbonate rock. The method comprises the following steps of performing appearance scanning on a rock core sample to obtain the initial surface roughness degree, performing acid etching treatment on the rock core sample by using acid liquid to be tested; performing appearance scanning again to obtain the surface roughness degree after acid etching after the acid etching treatment is completed, working out the surface roughness degree difference value of the surface roughness degree of the rock core sample after the acid etching and the initial surface roughness degree, and comparing the obtained surface roughness difference value with a threshold value so as to evaluate the acid fracturing effect of the acid liquid to be tested. The acid fracturing effect is evaluated through the appearance features of the surface of the rock core sample before and after the acid etching, so that the data reference and theoretical basis can be provided for the subsequent acid liquid screening, acidification fracturing design and optimization and carbonate rock acidification yield increase record recognition.

Description

technical field [0001] The invention relates to the field of oil and gas field development, in particular to an evaluation method for the acid fracturing effect of carbonate rocks. Background technique [0002] Acid fracturing is an effective stimulation measure to stimulate carbonate reservoirs. In the process of acid fracturing, when the preposition fluid or acid treatment fluid is operated with an injection displacement greater than the formation can accept, the pressure near the wellbore increases. If a certain pressure is maintained, the fracture will continue to extend, and with the injection of acid, acid-rock reaction will occur, and the acid will unevenly etch the formation fracture wall. If the design is proper, after the surface construction pressure is removed, the fracture will not close under the formation pressure, and the uneven etching channel with a certain conductivity makes the formation fluid flow into the bottom of the well relatively easily. If a non...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): E21B43/27E21B49/00
CPCE21B43/26E21B49/00
Inventor 周健蒋廷学姚奕明张旭东徐胜强吴峙颖
Owner CHINA PETROLEUM & CHEM CORP
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