Down-in type marginal oil field underwater drilling basal disc for drilling ship and manufacture and installation method

Abstract

The invention discloses a running type underwater drilling template of a drilling ship in a marginal oil-gas field, which comprises a main body framework and an accessory of the drilling template, wherein the main body framework is a rectangular framework body consisting of horizontal rods and vertical rods which are fixed together; the main body framework is provided with a vertical well hole sleeve two sides of which are fixed with pile pipe sleeves; and slanting knightheads are arranged in the rectangular frameworks which are formed between the horizontal rods and between the horizontal rods and the vertical rods. A method for manufacturing and mounting the underwater drilling template comprises the following steps: (1) manufacturing the underwater drilling template from both the upper part and the lower part simultaneously, and then welding the upper part and the lower part together; and (2) using a hoisting device to be connected with a cutting sleeve device on the top of the underwater drilling template and a lifting lug so as to hoist the underwater drilling template into water, wherein the convergence points of a hoisting rope in the hoisting device after the hoisting rope is straightened up are always positioned on the plumb line of the underwater drilling template so that the underwater drilling template is always kept in a horizontal state to get to the preset place on the sea floor. The underwater drilling template has the advantages of stable structure, reasonable stress, and lightened weight; the method for manufacturing the underwater drilling template can shorten the construction period; and the method for mounting the underwater drilling template is safe, smooth and convenient, requires fewer resources, and has low cost.

Description

technical field [0001] The invention relates to an underwater drilling template used in marginal oil and gas field development operations and a manufacturing and installing method thereof. Background technique [0002] With the expansion of offshore oil and gas development operations year by year, the demand for underwater drilling templates is increasing. The underwater template is a kind of equipment used in offshore oil drilling operations. It is placed at the wellhead of the seabed and mainly serves as a guide. Drilling tools, undertaking underwater wellhead devices and underwater blowout preventer groups, pre-drilling production wells according to the well spacing arranged on the underwater template, and using the guide piles on the template for docking and positioning of the jacket, etc. Subsea drilling templates with porous holes generally have 2 x 2 specifications, 2 x 3 specifications, 3 x 3 specifications, 3 x 4 specifications or even larger templates, and the weig...

AI Technical Summary

Problems solved by technology

Due to the large volume and weight of the underwater drilling template, for safety reasons, the underwater drilling template needs to be kept horizontal during the hoisting process, but due to the requirements of actual operations, the structure of the underwater drilling template usually cannot be designed to be symmetrical , the center of gravity of the underwater drilling template is not on the center of the underwater drilling template. Therefore, when the underwater drilling template is hoisted, in order to keep the underwater drilling template horizontal, wire ropes with different lengths must be used so that the wire rope is pulled The converging point after the straight line is above the underwater drilling template. At this time, the connection line between the converging point of the steel wire rope and the underwater drilling template is the heavy vertical line of the template. Therefore, it is difficult to determine the length of each steel wire rope. If the length of each steel wire rope is not suitable, during the hoisting process, the subsea drilling base plate will be tilted, and in severe cases, the force of a certain steel wire rope will exceed its bearing capacity. range, causing the wire rope to break, leading to safety accidents

In addition, after the underwater drilling template enters the water, due to the buoyancy of the underwater drilling template, the center of gravity of the underwater drilling template will shift compared with the center of gravity in the air, resulting in The lower drilling template maintains a horizontal balance in the air but tilts after entering the water

In addition, during the hoisting process of the underwater drilling template in the water, due to the action of the ocean current, the underwater drilling template has a large sway in the water, it is difficult to control the balance and stability of the underwater drilling template, and the underwater drilling template is increased. Difficulty in azimuth adjustment and positioning of drilling template

In the hoisting project of the existing underwater drilling template, the connection between the hoisting tool and the underwater drilling template is only through the flexible connection of the wire rope, which cannot exert force on the underwater drilling template well, and cannot be used well. Maintain balance and stability of the underwater drilling template, and perform position, azimuth adjustment and positioning underwater

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