Acid fracturing method for complex fractures in carbonate reservoir

Abstract

The invention discloses an acid fracturing method for complex fractures in a carbonate reservoir. The method comprises the following steps: determining the type of complex fracture morphology requiredfor communicating an oil-gas reservoir body according to the engineering geological condition of the region where the target well hole is located and the state of the oil-gas reservoir body, whereinthe type of the complex fracture morphology comprises one of a near-well reticular joint, a single main fracture and a far-well reticular joint, a plurality of main fractures and a far-well reticularjoint; and implementing corresponding acid-pressure strategies aiming at the complex fractures with different forms so as to form artificial fractures at different positions around the well, thereby communicating the oil and gas reservoirs in the target well hole area. The method can form a complex artificial fracture system, achieve the purpose of fracturing a plurality of oil gas reservoirs around the well by single fracturing, and increase the oil gas production degree around the well.

Description

Technical field [0001] The invention relates to the technical field of oil reservoir engineering, in particular to an acid fracturing method for complex fractures in carbonate reservoirs, which is used to increase the number and probability of communication between oil and gas reservoirs around the well and increase oil and gas production. Degree. Background technique [0002] Fractures and karst caves are the main oil and gas storage spaces and flow channels for carbonate reservoirs. The structure of the fractures and caves is complex, the development is discontinuous, and the heterogeneity is strong. It is difficult to predict the distribution of effective reservoirs in space. Due to the complexity of the distribution of fractures and caves, the limitations of detection technology, and the deviations in the precise control of the borehole trajectory during the drilling process, it is difficult for some target reservoirs to be directly connected through the borehole during the m...

AI Technical Summary

Problems solved by technology

Due to the complexity of the distribution of fractures and caves, the limitation of detection technology, and the deviation in the precise control of the wellbore trajectory during the drilling process, it is difficult for some target reservoirs to be directly connected through the wellbore during the production process.

At the same time, natural fractures are developed in the reservoir. During the fracturing completion process, conventional fracturing is dominated by a single main fracture, and its expansion path is difficult to control. The fractures tend to communicate with fracture-vuggy reservoirs in the direction of the horizontal maximum in-situ stress. Reservoirs are difficult to communicate, the effective communication rate is limited, the technical requirements for deep transformation are high, and it is difficult to stabilize production

In addition, with the expansion of oilfield development blocks, the development degree of reservoirs is getting worse and worse, and the communication rate of fractured-vuggy reservoirs and the average single well productivity are gradually decreasing, which seriously restricts the efficient development of this type of reservoirs.

[0003] Aiming at the exploitation of carbonate reservoirs, various scientific research institutes have carried out active exploration and research, but there are few technical methods related to the communication of oil and gas reservoirs in different complex fracture forms of carbonate reservoirs

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