Composite plugging material for well drilling and application thereof

Abstract

The invention provides a composite plugging material for well drilling and application thereof, belonging to the field of plugging technologies for oil and gas field exploration and development. The composite plugging material for well drilling comprises the following components in parts by weight: 1-2 parts of fibers, 50-70 parts of an inorganic silicon material, 15-35 parts of an elastic material and 13-14 parts of a tough material, wherein the elastic material is elastic graphite. According to the composite plugging material for well drilling, the inorganic silicon material and the tough material are used, so the composite plugging material for well drilling forms a plugging slug with certain strength under certain pressure, thereby realizing plugging; and when the elastic graphite is located in a crack, pressure generated by continuous opening-closing of the crack can be effectively resisted, so the plugging slug is not damaged, and re-leakage is avoided. In addition, the compositeplugging material for well drilling is suitable for water-based drilling fluids and oil-based drilling fluids, and is wide in application range.

Description

technical field [0001] The invention relates to the technical field of plugging in oil and gas field exploration and development, in particular to a composite plugging material for drilling and its application. Background technique [0002] Lost circulation is a common problem in the drilling process. It not only greatly increases the operating cost, but also increases the uncontrollable factors of drilling operations, which may lead to downhole complex accidents such as well collapse and blowout. This has higher requirements on the efficiency of drilling plugging technology. At present, the reasons for the failure of plugging mainly include the following points: 1) The strength of plugging materials is insufficient, such as commonly used plugging materials such as walnut shells, which are often crushed by pressure during the plugging process, resulting in failure to play a pressure-bearing role. 2) At present, SCT (Stress Cage Theory) stress cage theory is mostly used to g...

AI Technical Summary

Problems solved by technology

At present, the reasons for the failure of plugging mainly include the following points: 1) The strength of plugging materials is insufficient, such as commonly used plugging materials such as walnut shells, which are often crushed by pressure during the plugging process, resulting in failure to play a pressure-bearing role. 2) At present, SCT (Stress Cage Theory) stress cage theory is mostly used to guide the plugging construction, which directly manifests as the phenomenon of door sealing, usually because the particle size of the plugging material is designed with a single large particle as the core. Mainly, when encountering the swabbing effect in the follow-up construction, it is easy to cause regurgitation of the plugged part, resulting in re-leakage; 3) At present, some theories of plugging the center and tip of the fracture have been gradually accepted and applied by people, but the success rate It is also not ideal, especially when encountering induced fracture leakage, the fracture often produces a breathing effect during the drilling process, and the opening and closing actions occur repeatedly. If the plugging material is not well selected, it will be squeezed out of the fracture and regurgitation will occur lead to relapse

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