Oil-based plugging agent and preparation method thereof

Abstract

The invention discloses an oil-based plugging agent. The oil-based plugging agent comprises a sheet-like material, a flexible material, an elastic material and a rigid material; the fineness of the sheet-like material is less than 5 mm; the average length of the flexible material is 5-10 mm; the grain fineness of the elastic material is 0.5-5 mm; the grain fineness of the rigid material is 1-3 mm;and the weight ratio of the sheet-like material to the flexible material to the elastic material to the rigid material is (1-2):(2-3):(1-3):(0.5-1). The oil-based plugging agent disclosed by the invention has the advantage that plugging effects of microcracks, micropores and medium cracks can be improved. The oil-based plugging agent can plug cracks with different widths of 3 mm and below by being added to an oil base drilling fluid, and the pressure bearing reaches 7 MPa, and the leakage is reduced by 70%.

Description

technical field [0001] The invention relates to the technical field of chemical product manufacturing, in particular to an oil-based leak stoppage agent suitable for oil-based drilling fluid and a preparation method thereof. Background technique [0002] In the development of deep shale gas, the buried depth of the reservoir is greater than 3,500 meters, and the formation pressure coefficient increases from 1.45-1.50 to 1.60-1.80. Due to the development of micro-fractures in the formation, the degree of formation fragmentation increases, and the pressure-bearing capacity of the formation needs to be further improved. , in order to improve the cementing quality and prevent the cement slurry from leaking during the cementing process, it is necessary to further improve the pressure bearing capacity of the formation. Pressure endurance. At present, the plugging materials under pressure in China generally use conventional water-based plugging materials such as walnut shells and ...

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Problems solved by technology

At present, the plugging materials under pressure in China generally use conventional water-based plugging materials such as walnut shells and sawdust, etc., which are highly hydrophilic and easy to expand in the oil-based drilling fluid environment, deteriorate, degrade, and have poor plugging effect durability. Moreover, the compatibility with oil-based drilling fluid is poor, and effective plugging cannot be formed, which has a great impact on the rheological properties of oil-based drilling fluid

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