Method for managing annulus pressure of four-spud-in deep well

Abstract

The invention discloses a method for managing the annulus pressure of a four-spud-in deep well. The method includes the following steps that S1, a borehole is drilled in the surface layer by 70-80 m,and a marine riser is put down and fixed; S2, during first spud-in, a drill is taken out after the borehole is drilled to the position 600-700 m below the pulp surface, a first spud-in casing pipe isput down, and cement paste is injected into annulus gaps, and returns to the pulp surface; S3, during second spud-in, the drill is taken out after the borehole is drilled to the position 1,500-1,700 mbelow the pulp surface, a second spud-in casing pipe string is put down, the cement paste is injected into the annulus, and the top is controlled to the position 30-50 m below a suspender; S4, duringthird spud-in, the drill is taken out after the drill drills into a target layer, a third spud-in casing pipe is put down, a well mouth is installed, the cement paste is injected into the annulus, and cement first pulp returns to the position 110 m below a first spud-in casing pipe shoe; the annulus above the first pulp is filled with nitrogen, and the segment length of spacer fluid between the first pulp and tail pulp is 220-230 m; S5, during fourth spud-in, the drill is taken out after the borehole is drilled to the target layer, a tail pipe string is put down, the tail pipe string is suspended on the position 150 m above a third spud-in casing pipe shoe, the cement paste is injected, and next operation is executed after the cement paste is solidified. The problem that pressure is easily generated in the annulus of the four-spud-in deep well is solved.

Description

technical field [0001] The invention belongs to the technical field of drilling engineering of resources such as oil and natural gas, and in particular relates to a method for managing the annular space pressure of quarto sub-deep water wells. Background technique [0002] At present, many oil and gas wells at home and abroad have serious annulus pressure phenomenon. On land or offshore platforms with shallow water depth, it is relatively easy to manage the annulus pressure; On the bottom of the seabed with a water depth of one meter, it is difficult to deal with the problem of annular pressure. Therefore, it is necessary to manage well during the drilling process to avoid the problem of annular pressure after the drilling operation is completed. [0003] The traditional annulus pressure management of sub-quaternary deepwater wells is usually: (1) the surface layer is sealed with the full annulus, and the cement slurry is returned to the mud surface; The cement slurry is re...

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Problems solved by technology

[0005] The purpose of the present invention is to avoid the deficiencies in the prior art and provide a method for managing the annulus pressure in the sub-quaternary deep-water wells, so as to solve the problem that the sub-quaternary deep-water wells are likely to cause pressure in the annulus

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