Leak stopping mud bearing high pressure and used for fractured leakage

Abstract

The invention provides a leak stopping mud bearing high pressure and used for fractured leakage. The leak stopping mud comprises base mud, asphalt, an impervious filtrate loss reducer for a drilling fluid and a petroleum drilling well, a leak stopping fiber, a cross-linking tackifier and a high-strength propping agent. The leak stopping mud is composed of, by weight, 2 to 4% of sulfonated asphalt, 3 to 5% of the impervious filtrate loss reducer for the drilling fluid and the petroleum drilling well, 3 to 5% of the leak stopping fiber, 2 to 5% of the cross-linking tackifier and 3 to 7% of the high-strength propping agent, with the balance being the base mud, wherein the base mud is 4-7% bentonite mud. The leak stopping mud has a good leak stopping effect on fractured leakage of a complex gas field and can effectively improve stratal bearing capability, widen a drilling fluid safe density window and reduce repetitive leakage of plugging layers.

Description

technical field [0001] The invention relates to the field of plugging slurry for drilling fluid loss, in particular to a high-pressure plugging slurry for fractured leakage. Background technique [0002] Lost circulation is a common problem in the drilling process, which may cause downhole complex situations and major accidents such as well collapse, pipe sticking, and blowout. At present, the commonly used methods of plugging are mainly bridging plugging and chemical plugging. Bridging plugging is characterized by low cost and wide application, but its plugging success rate is low. The reason is that the bridging plugging material itself has poor deformability during the plugging process, and it is slightly larger than the pores and cracks of the leaking layer or is in contact with the pores of the leaking layer. Particles that do not match the shape of the cracks are not easy to enter, forming accumulations on the surface of the leakage layer, and do not penetrate in...

AI Technical Summary

Problems solved by technology

Chemical plugging has a good plugging effect on malignant leakage, but the chemical plugging reaction is more intense, the construction is complicated, and the risk is higher

[0003] At present, the pressure bearing capacity of most lost circulation agents is not high. When drilling in formations with high formation pore pressure, narrow safe density window, and multiple sets of pressure systems in the same open-hole section, the pressure balance is extremely difficult to adjust, which may easily cause leakage formations. Repeated leakage brings great difficulties to construction and seriously affects the progress and speed of exploration and development