Skid-mounted bradenhead gas four-tower separation recovery device and method thereof

Abstract

The invention claims a skid-mounted bradenhead gas four-tower separation recovery device and a method thereof; the device comprises a methane rectifying tower, an ethane rectifying tower, a propane rectifying tower and a heavy-component rectifying tower which are communicated with each other, wherein the methane rectifying tower is used for receiving gas components of the bradenhead gas which is desulfurized, cleaned, compressed and refrigerated to obtain methane with a purity of at least 95% at the tower top, and inputting tower bottom discharge material to the ethane rectifying tower; ethane with a purity of at least 95% is obtained at the tower top, and the discharged materials from the tower bottom are input to the propane rectifying tower; propane with a purity of at least 90% is obtained at the tower top, and the discharged materials from the tower bottom are input to the heavy-component rectifying tower; and butane with a purity of at least 90% is obtained at the tower top, and light oil with a purity of at least 90% at the tower bottom. Based on different components and contents of bradenhead gas, the bradenhead gas is separated and recovered with liquid-nitrogen low-temperature rectifying method; the whole device is skid-mounted; the separation recovery efficiency is relatively higher; and four types of products of dry gases (methane and ethane), liquefied gases (propane and butane) and light oil (C5+) can be obtained finally.

Description

technical field [0001] The invention relates to a wellhead gas separation and recovery device and method, more specifically, to a skid-mounted wellhead gas four-tower separation and recovery device and method. Background technique [0002] Wellhead gas mainly refers to associated gas at small stations, remote wells, and scattered low-yield gas wells in remote areas that are not suitable for building gas pipelines, and also includes flare gas at oil and gas gathering and processing stations. Due to the development difficulties such as low output and rapid pressure drop, this part of wellhead gas is exploited by conventional natural gas treatment technology, and the project investment and operation costs are high, which is uneconomical. [0003] At present, wellhead gas recovery is an economical and environmentally friendly technology, and its marketization process is accelerating. Various scientific research institutes and companies have also developed different processes. It...

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Problems solved by technology

The recovery of natural gas or associated gas carried out in many domestic oil fields is mainly for the recovery of liquid hydrocarbons, namely LPG, and the average recovery rate of propane is less than 60%.

At present, it is very difficult to achieve high-efficiency separation and recovery of wellhead gas on skid-mounted devices in China.

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