Method and device for determining fracture zone in rock stratum

Abstract

The invention discloses a method and device for determining a fracture zone in a rock stratum. The method comprises the following steps that a pressure sensor for acquiring pressure information of a fracturing fluid is arranged at a perforation section corresponding to a fracturing string; the fracturing string is filled up with the fracturing fluid, and then the fracturing fluid is injected at apredetermined displacement, and pressure build-up is carried out on a well bottom through formation fracture pressure to form a first artificial fracture section; a current first pressure curve section is acquired by using the pressure sensor; the fracturing fluid is injected continuously at the predetermined displacement so that the first artificial fracture section can extend forwards; a currentsecond pressure curve section is acquired by using the pressure sensor; and when the loss rate of fracturing fluid is greater than the injection rate and the current pressure obtained by the pressuresensor suddenly drops, it means that the first artificial fracture section communicates with the fracture zone. By means of the method and the device, the fracture zone in the rock stratum can be accurately and effectively identified, so that the requirements of oil field exploration and development can be well met.

Description

technical field [0001] The invention relates to the technical field of petroleum engineering, in particular to a method and a device for determining a broken zone in a rock formation. Background technique [0002] Fracture zones are bands of rock disrupted by haphazard cracks and fissures. Fracture zone data is a special geological body, and its structure is relatively complex. Generally, when the fractured zone is outcropped on the surface, it is easier to identify; but when the fractured zone is located underground, it is difficult to be identified, which causes many potential problems in the exploration and development of oilfields. Specifically, since the composition, thickness, and physical properties of some fracture zones will directly affect the extension mode of artificial fractures and the development of remaining oil, the identification and description of fracture zones has become a scientific and practical problem that needs to be solved urgently. difficult iss...

AI Technical Summary

Problems solved by technology

Among them, the fractured zone logging identification has a high recognition rate for the fractured zone, and can effectively identify open fractures and breccia zones, but the identification accuracy of calcite-filled fractures is not enough

In addition, the seismic identification of the fracture zone can obtain the overall spatial distribution of the fracture zone in the rock formation, but due to the limitation of the resolution of seismic data, it is difficult to identify a single small fracture zone

[0004] On the whole, there is still a lack of an effective method for identifying fractured zones in rock formations, so as to better meet the needs of oilfield exploration and development

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