Wellhead assembly bottom connecting device for shortening surface-drilling working time

Abstract

The invention discloses a wellhead assembly bottom connecting device for shortening surface-drilling working time, comprising a standard base assembly, a surface casing spindle hanger, an adapter joint and a wellhead assembly. A sealing unit with the outside diameter equal to the outer diameter of a surface casing is arranged at the upper end of the surface casing spindle hanger, extends to a lower inner cavity of the wellhead assembly, and is hermetically connected with the inner wall of the lower cavity of the wellhead assembly through a sealing device; a connecting unit is arranged below the surface casing spindle hanger and is in threaded connection with the adapter joint; a locking bolt connected with the upper end of the surface casing spindle hanger is arranged at the lower end of the adapter joint; a plurality of connecting bolts are arranged at the bottom of the wellhead assembly, and the adapter joint is connected with the wellhead assembly detachably through the connecting bolts. The wellhead assembly bottom connecting device has the advantages of saving time for cleaning the sealing surface, simplifying assembling of the wellhead device, shortening time for drilling andwell completion work and improving field operation efficiency.

Description

technical field [0001] The invention relates to the technical field of oil drilling and production, in particular to a bottom connecting device of a wellhead device used for shortening the drilling operation time of a first opening. Background technique [0002] At present, the connection methods between wellhead devices and surface casings at home and abroad basically adopt three types: threaded bottom connection, inverted slip bottom connection and welded bottom connection. [0003] The threaded bottom connection is that the bottom of the wellhead device and the surface casing are directly connected by casing threads. This bottom connection method has the following three disadvantages. First, the threaded connection method is complicated, and the casing hydraulic caliper cannot clamp the wellhead device to tighten the surface casing. Turn the wellhead device to the specified torque and tighten it on the surface casing. Second, the cementing operation is complex and requi...

AI Technical Summary

Problems solved by technology

This bottom connection method has the following three disadvantages. First, the threaded connection tightening method is complicated. The casing hydraulic caliper cannot clamp the wellhead device and tighten it to the surface casing. Turn wellhead to specified torque and tighten to surface casing

The second is that the cementing operation is complex and requires a special cementing tool. The lower end of the tool is connected to the drill pipe short and the sealing plug, and then cement is injected from the inside of the drill pipe to prevent the cement from adhering to the inner hole of the casing head. Each sealing surface

The third is that the bottom connection method cannot realize emergency connection. When the surface casing is stuck and lowered to a specified depth, it cannot be directly converted from the threaded bottom connection to the emergency slip connection.

The bottom connection can only be carried out after the surface casing is completely cemented, and a series of operations such as casing cutting and grinding are required, which increases the drilling operation time and reduces work efficiency. See image 3

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