RU2392171C2 - Method for development of hydrocarbon deposits on super-shallow shelf (sea depth = 1,1-1,3 m) - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: floating structure is composed of two serially manufactured bodies of metal moorages for large military ships equipped with serial devices. The bodies are connected above the water level with a bridge. Mounted on the floating structure are a serial drilling facility MBK-125, a drilling fluid circulation system, a power plant, a positioning system. The structure is brought to the drilling place, dropped onto the ground accepting water ballast and fixed with the help of pile devices. One performs well drilling; after its completion the structure is lifted and transported to another place.

EFFECT: possibility to develop deposits at depths specified (1,1-1,3 m).

2 dwg

Description

The invention relates to a method for mining in shallow water.

The main ways of creating a floating drilling complex for hydrocarbon production in extreme shallow water are known due to a set of measures:

- reduce draft;

- ensuring its mobility for approaching in shallow water;

- statement on the ground;

- reliable fixing on the ground;

- removal from the ground;

- the ability to maneuver to perform tasks directly at the drilling point.

At the Obsky-1 floating drilling complex, designed for drilling exploratory wells, these tasks are solved by dividing the complex into two components:

I - floating submersible drilling rig (PPBU), designed for drilling exploratory oil and gas wells at sea depths from 4 to 10 meters;

II - a floating base for integrated drilling support, designed to ensure the functioning of the control system and the residence of staff (www.gazprom.ru/child/gazf100.shtml).

The installation of SSBFs on the ground is ensured by the use of ballast water and the use of a skirt with a height of up to 500 mm in the construction of the bottom (Abstracts of the International Conference RAO-01, p. 441, 2001, St. Petersburg).

The present invention is directed to solving a set of tasks for the development of hydrocarbon deposits on a shallow shelf, for example, the Northern Caspian with a sea depth of 1.1-1.3 meters.

In order to obtain low draft, two mass-produced hulls of metal berths (already existing) 8 are used for large warships and equipped with retractable pile devices.

Pontoons are connected above the water level by a bridge 7 located along the longitudinal generatrix of the buildings, forming a single structure with sliding support devices 3 at the corners. On the bridge, on a special portal 2, a serial mobile drilling rig of the MBK-125 type is installed (tower 1 in the drawing), which under normal conditions is based on a car chassis.

To ensure drilling at a given depth, blocks of serial mechanisms 5 are additionally installed on the pontoons, which ensure the preparation and circulation of the drilling fluid, and an energy installation (power station 6), which ensures the operation of the circulation system mechanisms.

When setting to the drilling point (wellhead 9), ballast water is taken into the ballast tanks 4, the structure is lowered to the ground and stopped by the lowering retractable pile devices 3 of the pontoons located at the corners of the structures and pressed into the ground by an electric drive, thereby ensuring immobility during drilling.

In order to combat sea pollution in the pontoon hull, tanks are provided for draining leaks 10. After drilling is completed, leaks are diverted to the supply vessel.

To prevent flooding during a storm, mechanisms are installed on elevated foundations 11.

After drilling, the retractable pile devices are lifted using, if necessary, a soil erosion system, ballast water is pumped out, the structure floats up and is towed to a new drilling point.

The height of the bridge connecting the pontoons ensures the passage of the structure over the constructed and plugged well and does not require underwater welding, and to ensure the strength of the complex, the hulls of the metal berths are connected along the longitudinal generatrix of the hulls.

The rig is supplied with consumables, pipes and tools, as well as personnel are changed using shallow vessels.

The facility is equipped with a positioning system, which should provide:

- accuracy of setting the platform to the drilling operating point;

- removing the platform from the operating point by moving it, at which the wellhead remains constantly between the pontoons of the body under the bridge, which has a clearance relative to the water level.

Claims (1)

A method for developing hydrocarbon deposits, mainly liquid and gaseous, on a super shallow shelf at a sea depth of 1.1-1.3 m, in which a floating technological structure with a serial drilling rig installed on it, blocks of the circulation system mechanisms for preparing and circulating the drilling fluid, a power plant (power plant), sliding pile devices and a positioning system are lowered to the ground, taking water ballast from the side, and the well is drilled depth, and after the drilling process is completed, the structure is lifted and transferred to the next drilling site, characterized in that the technological structure building consists of two mass-produced hulls of metal berths for large military ships connected by a bridge located above the water level along the longitudinal generatrix of the hulls, this uses pile devices located at the corners of the structure and pressed into the ground to secure the structure when drilling using an electric drive, drilling of a well The installed depth is carried out by the MBK-125 serial mobile drilling rig, mounted on a bridge on an elevated portal, using additionally installed blocks of the circulation system mechanisms, the drilling products are discharged to the leakage drain tank, and after the structure has been lifted, it is transferred to the next drilling location using the positioning system .