Fastening method and device for oil production wellhead bolts

Abstract

The invention discloses a tightening method for a wellhead bolt of oil extraction well and a device thereof, and relates to the technical field of oil gas development. The method comprises the following steps that, a workover rig hydraulic system is connected with a multi-port hydraulic power balance distribution device; two hydraulic transmission pipelines are connected to each hydraulic terminalof the multi-port hydraulic power balance distribution device, and the hydraulic transmission pipelines are connected with hydraulic control wrenches separately; bolts and nuts are assembled on assembled flanges of a wellhead; the hydraulic control wrenches are installed on the bolts of the wellhead, and the number of the bolts is matched with the number of the hydraulic control wrenches; and themulti-port hydraulic power balance distribution device is controlled to enable hydraulic pressure to be transmitted to the hydraulic control wrenches, and meanwhile, the nuts on the flanges of the wellhead are tightened by the hydraulic control wrenches. According to the tightening method, the oil wellhead bolts can be tightened at the same time.

Description

technical field [0001] The invention relates to the technical field of oil and gas development, in particular to a method and device for fastening oil wellhead bolts. Background technique [0002] Oil production wellhead is the most common oil production equipment in the field of oil field production. Generally, there are two types of connections between various parts of the oil production wellhead. The first is the clamp slip connection, and the second is the flange connection. The first type of clamp connection is to use special slips and slip screws, but because the slips only have two or four holes, the force is not balanced, so it is basically no longer used in the field. The second type of flange connection is widely used in the field, that is, the outer diameter of the flange is 380mm, and there are 12 screw holes on the upper part, with a steel ring in the middle, and M46 bolts are used to connect the two flanges to achieve sealing. effect. [0003] At present, 12 ...

AI Technical Summary

Problems solved by technology

Due to the existence of flammable and explosive substances such as flammable gas, hydrogen sulfide, and crude oil at the wellhead of oil production, electric tools cannot be used in all operations, so the above installation and fastening operations are manual operations

But there are following problems in on-the-spot construction: one, the wellhead bolts are all artificially smashed tightly with a wrench and an iron hammer one by one

The above operations will cause the bolts to be unbalanced in the axial direction, that is, when the screws are tightened one by one, there will often be a problem of large gaps on one side of the steel ring, which may lead to accidents such as natural gas or crude oil leakage, and even worse. Well Control Danger

2. The bolts are not fastened diagonally together during routine operations on site. The bolts at each flange connection are completed one by one, which requires repeated operations for 12 times. One operation well requires 4 operations before repairing and after completion. connection, a total of 48 bolts, labor-intensive

3. Diagonal screws were not tightened at the same time during the on-site construction. On the surface, it seems that the force is balanced. In fact, the flange after the completion of the well is likely to be biased at one end, but it cannot be accurately judged by the naked eye on site.

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