Fracture monitoring method by CT scan for hydraulic fracture initiation and propagation of large-scale volcanic rocks

Abstract

The invention provides a method for carrying out fracture CT (Computed Tomography) scanning and monitoring on initiation and extension of a large-size volcanic hydraulic fracture, which belongs to the field of volcanic gas reservoir and fracturing during oil and gas field development. The method is characterized in that CT scanning is respectively carried out on a rock sample of a volcanic before and after a hydraulic fracture physical modeling fracture test, and the monitoring on the large-size volcanic hydraulic fracture and intuitive analysis on a fracture initiation and extension rule of the hydraulic fracture can be realized through comparing changes of the rock sample before and after the test. According to the method provided by the invention, a fracture initiation and extension process of each scanning cross-section fracture can be clearly and intuitively reflected under the situations of different primary stress differences before and after fracturing, rock pore, development degree of a natural fracture and discharge capacity and viscosity of a fracturing liquid, and an important role is played in researching a fracturing fracture initiation and extension mechanism which adapt to characteristics of multiple fractures and fractured-vuggy reservoir of the volcanic.

Description

technical field [0001] The invention belongs to the field of fracturing of volcanic rock gas reservoirs in the development of oil and gas fields, and in particular relates to a large-size volcanic rock hydraulic fracture initiation and expansion CT scanning crack monitoring method, which is applicable to both large-size rock samples and small-size rock samples, but The experimental results obtained by simulated pressure experiments on large-scale rock samples are closer to reality, and the shape of hydraulic fractures obtained by large-scale rock samples is clearer. Background technique [0002] At present, in some oil and gas fields of Sinopec, such as the Songnan Gas Field of the Northeast Branch, the Tarim Basin of the Northwest Branch, the Dongying Sag of the Shengli Oilfield, and the Jiyang Sag of the Huimin Sag. Volcanic rock oil and gas fields have been discovered in the Min Sag, the Permian System in the Tarim Basin of Northwest Branch, and the Dongtai Depression in ...

AI Technical Summary

Problems solved by technology

This method has two disadvantages: one is that in the process of splitting, the original cracks are bound to be destroyed, or new cracks are formed on the basis of the original cracks, which greatly affects the accuracy of the experimental results

Second, in terms of multi-fracture observation, the conventional observation method after fracturing is to split the sample along the main fracture. As a result, only the main fracture surface can be observed, while the development of other fractures is destroyed.

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