Re-fracturing method for oil, gas and water wells

Abstract

The invention provides a re-fracturing method for oil, gas and water wells and belongs to the field of oil and gas exploration. The method comprises steps of preparing: ensuring a downhole casing of a fracturing section of an oil, gas and water well is in normal operating state; sealing: sealing at least part of old fractures in the oil, gas and water well; re-fracturing: re-fracturing the oil, gas and water well at the fracturing section to generate new fractures. The method forms a sealing and fracturing technique, old fractures are sealed in long time or preferably temporarily sealed through a determination device and a sealing agent, and new fractures are then made by pressing in other directions of a formation by a hydraulic fracturing process so as to reform a reservoir.

Description

Technical field [0001] The invention relates to the field of oil and gas exploitation, in particular to a method for repeated fracturing of oil and gas wells. Background technique [0002] Due to the poor physical properties of the reservoir, the production of oil wells in low-permeability oil and gas reservoirs is usually low, and due to the complex pore structure and abnormal seepage state, the development characteristics of their oil fields are very different from those of medium-high permeability oil reservoirs, even in comparison. A qualitative change has taken place. [0003] The development of low-permeability oil fields has the following basic characteristics: (1) The natural productivity of oil wells is low, and it has industrial production value after fracturing; (2) The seepage law does not follow Darcy's law and has a starting pressure gradient; (3) Natural energy is small, Pressure and production decline rapidly, and the primary recovery rate is low; (4) The fluid pro...

AI Technical Summary

Problems solved by technology

[0006] For oil, gas, and water wells after hydraulic fracturing, due to the limitation of fracturing technology, materials, equipment and tools, the scale is not small, the selection of materials is improper, and the power of equipment is limited, etc., the conductivity of hydraulic fractures will be greatly reduced. , thus gradually losing its effect; some of them failed to effectively maintain their conductivity due to improper well layer selection or operational reasons; at the same time, after long-term development, major oil and gas fields have entered the development stage of medium and high water cut periods, and the high and stable production more and more difficult

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