Method for controlling fracturing of multiple fractures of oil and gas field with natural micro-fracture-developed reservoir stratum

Abstract

The invention provides a method for controlling fracturing of multiple fractures of an oil and gas field with a natural micro-fracture-developed reservoir stratum. By adopting the early high-sand-ratio powdery ceramsite proppant slug technique, a few ceramsites are injected by a high-sand-ratio proppant slug at a prepad fluid stage to plug natural fractures of the reservoir stratum, and therefore, the generation of the multiple fractures is effectively controlled and reduced, and the construction success rate and the post-fracturing effective rate are improved. With the high-sand-ratio proppant slug entering the stratum, all cracks of which the crack width is smaller are plugged. New multiple fractures during the extension process of a major fracture are plugged by a low-sand-ratio proppant slug at middle and later periods. After the high-sand-ratio proppant slug is added, as proved by fitting construction net pressure, the natural micro-fractures are largely plugged, and the pressure of the reservoir stratum slightly rises. As the multiple fractures are effectively controlled, the construction pressure is stable, and the goal that the multiple fractures are controlled to form the major fracture is achieved. Proved by a test in Yao Ying Tai oil field of Jilin province, the fracturing method for controlling multiple fractures of the oil and gas field with the natural micro-fracture-developed reservoir stratum has the advantages that the implementation is simple, the application is convenient, and the multiple fractures are effectively controlled, and is suitable for being applied to the reform of the natural micro-fracture-developed reservoir stratum.

Description

technical field [0001] The invention relates to a new method for oil-gas field reservoir reformation, in particular to an oil-gas field controlled multi-fracture fracturing method for reservoirs with well-developed natural micro-fractures. Background technique [0002] At present, the view that multiple fractures exist in the fracturing process of oil and gas fields has been widely recognized. With the development of complex lithology such as marl, basalt, and volcanic rock, and the increasingly complex wellbore conditions, the existence of multiple fractures in the fracturing process of oil and gas fields has become a major obstacle to the development of fracturing stimulation measures. The current method of controlling multiple fractures is mainly to use slug reducer. Commonly used filter reducers and plugging agents include silt, combined ceramsite, oil-soluble plugging agents, emulsion fluid loss control agents and rubber plugs. However, ordinary stepped slugs are gener...

AI Technical Summary

Problems solved by technology

The traditional slug drop filter is to add powder pottery with a sand liquid volume ratio of 4-6% when the preflush is 20-30 cubic meters. Because the crack width is large, many cracks cannot be effectively blocked.

This technical method is not very effective in sealing multiple cracks, and it is easy to shorten the length of the main crack and narrow the width of the crack, resulting in a gradual increase in construction pressure and increased construction difficulty.

This method of adding sand is likely to cause screenout problems during the migration of proppant inside the fracture.

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