Oilfield associated gas comprehensive utilization method

Abstract

The invention provides an oilfield associated gas comprehensive utilization method, which comprises three sections of condensate oil preparation, hydrocarbon separation and product extraction, and adopts a step-by-step pressurizing liquefaction product separation and step-by-step drying dehydration method for oilfield associated gas. According to step-by-step pressurizing liquefaction, componentsabove C2 can be separated by first -stage pressurization, CO2 and methane are separated through two-stage pressurization, and liquefied methane gas is subjected to three-stage pressurization to produce an LNG product. And step-by-step drying dehydration is conducted, after most C5 and components above C5 are separated from the associated gas coming from an inlet gathering and transportation pipeline through pressurization dehydration, the associated gas is subjected to first-stage dehydration drying to the dew point of -100 DEG C, the C2, components above C2 and CO2 are separated out, and finally natural gas liquefaction is conducted after the associated gas is subjected to third-stage dehydration drying to the dew point of -180 DEG C. The process energy consumption is reduced to the maximum extent, product diversification can be achieved, product transportation is not limited by surrounding conditions of an oil field, high environmental protection benefits and economic benefits are achieved, and comprehensive and efficient utilization of the oil field associated gas is achieved.

Description

technical field [0001] The invention belongs to the technical field of oilfield gas recovery and separation, and in particular relates to a comprehensive utilization method of oilfield associated gas. Background technique [0002] Oilfield associated gas, also known as oilfield gas, is a gas that escapes from oil wells. Its main components are low molecular alkanes such as methane (C1) and ethane (C2), and a certain amount of propane (C3), butane alkanes (C4) and pentanes (C5) and above heavy components (C5+), and acid gases such as H 2 S and CO 2 , the acid gas concentration varies in different oilfields. [0003] Such as figure 1 As shown, the typical route of the existing oilfield associated gas recovery technology can be summarized as follows: the wellhead associated gas enters the pressurization unit after pretreatment to remove sand and water; the condensate produced during the pressurization process enters the heavy hydrocarbon stabilization unit, and the produced ...

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Problems solved by technology

[0009] 2. The normal pressure boiling point of the lean gas after the separation of heavy hydrocarbons in the above process is too low, for example, the normal pressure boiling point of C1 is about -160°C, so it is difficult to liquefy or transport under high pressure, and its lean gas products are restricted by the surrounding power plants or long-distance pipeline network Or CNG tanker, transportation is difficult

[0010] 3. When the CO contained in the oilfield associated gas 2 H 2 In case of S, when the alcohol amine absorption method or membrane separation or pressure swing adsorption deacidification is used, the H in the acid gas produced 2 S concentration is too low for sulfur treatment by Claus process

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