SU1521825A1 - Method of setting an ice-resistant offshore foundation for drilling survey and production wells - Google Patents

Abstract

FIELD OF THE INVENTION The invention relates to hydraulic engineering. The purpose of the invention is to increase efficiency by reducing the cost of construction and operation of technical means for the development of the shelf. The base is assembled afloat from sections that differ in the height of the bead by their ballasting, turning and re-ballasting of the piles formed from the casing-direction and the casing-conductor, the piles are lowered using standard drilling equipment. The column-direction is installed in a pre-drilled well and cement, after which a conductor column is installed coaxially. The method allows more flexible use of the expensive section carrying technological and ship equipment in various areas of the shallow shelf without increasing the number of sizes of such sections, as well as more fully using the drilling equipment. 3 il.

Description

The invention relates to hydraulic construction, in particular to submersible structures for drilling field and exploration wells on the shallow shelf.

The aim of the invention is to increase efficiency by reducing the cost of construction and operation of technical equipment for the development of the slot.

FIG. 1 shows a displacement base mounted and fixed on the ground with the help of piles; in fig. 2 - the section carrying the drilling equipment, side view; in fig. 3 - the same, top view.

The method is carried out as follows ./

Sections 1-3 of the displacement base, selected by composition and number depending on the operating depths in the drilling area, and platform 4, which carries drilling equipment, are delivered to

the area of drilling in a displacement position, or in some other way, and form of them displacement base and ice-resistant submersible structure as a whole.

Sections 1-3, standardized in terms of dimensions and docking surfaces, are ballastised, tilted by 90 to a position suitable for docking, and joined to each other. At the same time, the docking is facilitated by the self-centering shape of the docking surface of the sections.

After docking, re-ballasting of sections I-3 assembled into the displacement base is made, reoriented to the position preceding docking.

Subsequent ballasting gives the base a negative buoyancy and is immersed on the seabed.

Platform 4 winds afloat into position above the submerged base, ballast

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Flush and heat up before landing on it;

 The drilling rig 5 is moved to extreme locations over the drilling shaft 6 and through the sk, the mine shafts 7, passing through sections 1-3 and platform 4, are made for drilling wells to a depth that depends on the characteristics of the soil.

; With the help of a drilling tower 5, the first casing-direction 8 is lowered with the end of the bottom at the level of sea Kciro, followed by fixing it to He, the ground by cementing with standard equipment for drilling and casing trutb

i The second conductor casing 9 y {: is stopped with termination on the deck for the period of drilling operations, and is also dismantled with the help of a derrick before leaving the drill.

I Assemble of two casing strings 8 and 9 form a pile, the lower part of which — direction 8 remains in the ground after the structure is removed from the drilling point, i.e., is a consumable material, and the upper one - jig 9 is used repeatedly.

The dismantling of the structure is carried out in reverse order.

The applied principle of the composite water-bearing base allows more expensive use of the expensive section. Carrying technological and ship equipment, in various areas of the shallow water shelf, without increasing the number of types (() sizes of such sections. This leads to a reduction) of capital expenditures on creation (Means for the development of the shelf.

The use of standard materials and standard drilling equipment for drilling a well cluster to build a pile base allows freeing stationary equipment for installing removable piles to reduce the cost of construction, both by reducing equipment costs and by better utilization of useful volumes and areas. .

Claims (1)

Invention Formula A method of installing an offshore ice-resistant base for drilling field and exploration wells, including immersing the base on the seabed and fixing it on the bottom with piles, characterized by so that, in order to increase efficiency by reducing the cost of building and operating the technical means for the development of the shelf, the foundation is formed afloat from separate sections, for which they are turned into a vertical position with ballasting, they are joined to the vertical position and rebalanced sections in a horizontal position, after which the base is immersed at the bottom by receiving additional ballast, the platform with standard drilling equipment is brought to the base, and the ballasting is immersed Before joining with the base, and with the help of standard drilling equipment, piles formed of concentrically connected casing - columns-directions and columns-conductors are lowered through vertical shafts passing coaxially through the platform and the base, for which the well is drilled. the number of mines is installed in the well casing-direction with the end at the bottom of the sea, cement them in the ground, then install the casing-conductor with the end on the platform. srig.2 fig.Z