Packer for high-temp thermal recovery

Abstract

A packer for high-temp steam recovery of high-viscosity petroleum is composed of upper joint, special corrugated pipe, central pipe, expanding head and its internal and external sealing rings and external sleeve, nozzle and its fixed retainer ring, hydraulic valve and its sealing ring and restoration spring, and lower joint. Its advantages include high reliability and high temp resistance (450 deg.C).

Description

(1) Technical field [0001] The invention relates to a thermal recovery packer, which is a downhole tool suitable for steam huffing and puffing or steam flooding in high-viscosity oilfields to exploit heavy oil, and belongs to the technical field of petroleum exploitation. (2) Background technology [0002] Steam stimulation and steam flooding are effective technical methods for heavy oil recovery. The thermal recovery packer is an important component of the steam injection string. It prevents high-temperature steam from entering the annular space composed of casing and heat-insulating pipe, thereby reducing heat loss in the wellbore, improving the dryness of bottom-hole steam, and protecting the oil layer. The role of casing. At present, the relatively successful heat-expandable metal thermal recovery packers used under high temperature conditions of 300°C to 450°C rely on the support of the liner to form an initial seal. After steam injection for a period of time, the oute...

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Problems solved by technology

At present, the relatively successful heat-expandable metal thermal recovery packers used under high temperature conditions of 300°C to 450°C rely on the support of the liner to form an initial seal. After steam injection for a period of time, the outer surface of the heat-expandable A permanent seal is formed on the casing wall of the steam well. As the heat insulation tube is heated and elongated, a relative movement occurs between the outer surface of the thermal expansion body and the inner wall of the oil well casing. During the movement, the outer surface of the thermal expansion body is worn, and the Gaps are formed between casings, making it difficult to ensure their sealing performance

Especially when the seal is severely worn, its sealing performance is almost lost, and the high-temperature steam injected into the heat-insulating pipe with a temperature of 300°C to 450°C will directly enter the casing cavity of the oil well, causing the casing to bend due to heat, and eventually the casing pipe waste, causing huge economic losses

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