An overpressure protection method for an underwater methanol injection system

By installing dual safety release valves at the methanol injection pump outlet and controlling the isolation valve, the problem of overpressure during methanol injection in subsea production gas fields was solved, achieving overpressure protection and safe operation of the equipment, reducing the design pressure of the cross-connection pipe, and expanding the application range.

CN116255114BActive Publication Date: 2026-06-16OFFSHORE OIL ENG CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
OFFSHORE OIL ENG CO LTD
Filing Date
2023-02-27
Publication Date
2026-06-16

AI Technical Summary

⚠Technical Problem

After the underwater gas field is shut down, the methanol injection pressure exceeds the design pressure of the cross-connector, causing equipment damage and environmental pollution. Existing technologies are not effective in protecting against overpressure.

⚗Method used

First and second safety release valves are installed at the outlet of the methanol injection pump and controlled by isolation valves to provide overpressure protection for the wellbore and cross-connection respectively, with different release values ​​set to prevent overpressure.

🎯Benefits of technology

It achieves overpressure protection for methanol replacement operations of subsea wellheads and crossovers, avoiding equipment damage and environmental pollution, reducing the design pressure requirements of crossovers, and expanding the application scope.

✦ Generated by Eureka AI based on patent content.

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Abstract

The application discloses a kind of underwater methanol injection system overpressure protection method, it is related to marine engineering technical field, it is applicable to the wellbore of underwater Christmas tree and jumper pipe methanol replacement, comprising the following steps: S1: methanol replacement equipment is set in downstream support platform, the methanol replacement equipment includes methanol injection pump;S2: according to the pressure estimation of wellbore and jumper pipe and set the discharge pressure of above-mentioned methanol injection pump;S3: first safety relief valve PSV and second safety relief valve PSV are set in the outlet of above-mentioned methanol injection pump, and isolation valve is set in the inlet of first safety relief valve PSV and second safety relief valve PSV;S4: the overpressure protection of wellbore or jumper pipe methanol replacement operating condition is carried out by switching above-mentioned isolation valve;Double safety relief valve PSV design can be set different pressure release value for the replacement operation of underwater Christmas tree and jumper pipe, overpressure protection is carried out by isolation valve, meet the overpressure protection needs of methanol replacement operation of different design pressure system equipment underwater.
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