Pressure-bearing plugging agent for offshore drilling fluid and application method thereof

Abstract

The invention discloses a pressure bearable plugging agent for a marine drilling fluid and an application method therefor. The pressure bearable plugging agent consists of the following components in parts by weight: 10-20 parts of bauxite powder,10-20 parts of sodium soil, 20-35 parts of coal ash, 20-25 parts of wood fiber powder, 10-15 parts of composite salt-resistant polymer, 10-25 parts of furfural residue powder, and 0.5-1 parts of a crosslinking agent. When in use, 15-25 kg per cubic meter of a pressure bearable plugging agent is added to well drilling mud, then a drilling operation is performed; the pressure bearable plugging agent can greatly improve permeability resistance performance of drilling fluid, so that the drilling fluid and filtrate fluid of the drilling fluid are stooped from infiltrating into a deep portion of an oil-gas layer, thereby realizing near zero fluid loss drilling, and thus basically solving a pollution problem caused by the oil-gas layer in drilling engineering. Meanwhile, as the membrane structure is formed on a shallow surface of a permeable layer, and does not permeate the deep portion of the oil-gas layer; when there is a counter pressure in a wellbore, the plugging agent can be removed by itself; and a recovery value of permeability may be above 90%, thereby effectively protecting an oil-gas layer.

Description

technical field [0001] The invention relates to the technical field of petroleum production and development, in particular to a temporary plugging agent for preventing drilling fluid from leaking into oil layers in offshore drilling engineering. Background technique [0002] Oil development starts with drilling, which is the most basic procedure of exploration and development. A new oil field needs to be drilled for many oil wells and water injection wells, and the development adjustment of an old oil field also requires drilling more oil wells. Drilling engineering requires drilling fluid, and the performance of drilling fluid not only has a major impact on the quality of drilling engineering, but also plays a key role in the protection of oil layers. [0003] Drilling fluid loss will occur when the following situations are encountered during the drilling process: 1. Oil and gas layers with special properties, such as large pores and fractured oil and gas layers; 2. Oil and...

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Problems solved by technology

[0006] The purpose of the present invention is to address the defects in the prior art, to provide a pressure-bearing plugging agent for marine drilling fluid with good leakage prevention performance and its application method, so as to solve the problem of drilling fluid leakage in offshore drilling engineering and the problems caused by drilling. Pollution of Oil and Gas Reservoirs Caused by Liquid Leakage

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