Offshore thick oil heat injection and oil extraction pipe column and method

Abstract

The invention relates to an offshore thick oil heat injection and oil extraction pipe column and method. A sand control screen pipe is divided into a heat injection cavity and an oil extraction cavity; check valves are mounted at the tops of the heat injection cavity and the oil extraction cavity; the sand control screen pipe is connected with an oil layer casing; a center pipe column can be repeatedly put down; an oil pipe is connected with an electric submersible pump set, and is connected to ground power supply equipment through a cable; and an underground safety valve is mounted in the oil pipe, and is connected to a ground hydraulic supply device through a hydraulic control pipeline. In a heat injection phase, after a heat medium is injected from the center pipe column, the check valve allowing flowing into the screen pipe is opened, the check valve allowing flowing out of the screen pipe is closed, and the heat medium flows into an oil pool storage layer through the heat injection cavity; and in an oil extraction phase, the check valve allowing flowing out of the screen pipe is opened, the check valve allowing flowing into the screen pipe is closed, and an oil pool fluid flows into the oil extraction cavity from an oil pool. The pipe column reduces the washout influence on the sand control screen pipe from the two-way flowing and the temperature change, reduces the damage of the sand control screen pipe from the heat extraction operation, and prolongs the service life of an oil well.

Description

technical field [0001] The invention relates to an offshore heavy oil heat injection and oil recovery pipe string and a method thereof. Background technique [0002] Thermal huff and puff oil recovery is the leading technology in the development of heavy oil fields. Due to the shallow burial of heavy oil reservoirs, relatively loose reservoirs and easy sand production, it is necessary to use sand control screens for well completion. In the process of thermal stimulation, heat medium such as steam flows from the wellbore to the reservoir through the sand control screen in the heat injection stage, and the reservoir fluid flows from the reservoir to the wellbore through the sand control screen in the oil production stage. The two stages of production are subject to erosion in different directions, which will accelerate the destruction of the sand control screen. At the same time, due to the large temperature changes in the two stages of heat injection and oil production, the...

AI Technical Summary

Problems solved by technology

[0003] The failure of the sand control screen will cause the screen to lose its sand-retaining function, resulting in sand production in the oil well and shutdown. Usually, overhaul operations or re-sidetracking are used to solve the problem of sand production, and the later investment costs are very high.

Images