Development method of offshore small-scale gas reservoir

Abstract

The invention discloses a development method of an offshore small-scale gas reservoir. The method is characterized by comprising the following steps of: (A) selecting a developed gas field production gas reservoir, and selecting a small-scale gas reservoir to be developed, which is suitable to be developed by adopting the method, in the gas field or around the gas field; (B) selecting a proper offshore position for a drilling ship for taking the place, and establishing an artificial natural gas migration channel between a gas reservoir sand body of the developed gas field production gas reservoir and a small-scale gas reservoir through well drilling and well completion so as to develop the small-scale gas reservoir; and (C) developing the gas reservoir by utilizing a production platform of the developed gas field production gas reservoir or an underwater production system, wherein natural gas in the small-scale gas reservoir enters the gas reservoir sand body of the developed gas field production gas reservoir through the artificial natural gas migration channel under the action of pressure difference, flows to a production well of the production platform or the underwater production system by taking the gas reservoir sand body as a conduction layer and finally flows out of the production well of the production platform or the underwater production system so as to realize the development to the small-scale gas reservoir. According to the development method, through establishing the artificial natural gas migration channel, the traditional development platform or the underwater production system is sufficiently utilized so as to shorten the development period and reduce the investment cost.

Description

Technical field [0001] The invention relates to a method for developing natural gas, in particular to a method for developing a small-scale offshore gas reservoir. Background technique [0002] Small-scale gas reservoirs refer to small-scale gas reservoirs with only 250 to 2.5 billion cubic meters of recoverable reserves. The existing offshore gas field and small-scale gas reservoir development methods are all developed by drilling production wells using conventional offshore production platforms or underwater production systems. Under normal circumstances, for small-scale gas reservoirs, due to the small recoverable gas volume and relatively high investment in drilling and completion, if a well slot is installed outside the existing production platform or an underwater wellhead is added to the existing underwater production system, it will further increase Investment, and new production platform or underwater production system engineering investment is higher, resulting in ...

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Problems solved by technology

The above-mentioned development methods have the following disadvantages: 1. The drilling and development of new production platforms or underwater production systems, from the construction of new production platforms or underwater production systems to production, has a long cycle and large investment, and it is difficult to realize the drilling in or around the developed offshore gas fields. The economical and effective development of small-scale gas reservoirs will also cause the existing well pattern and existing production facilities of the developed gas field production platform or underwater production system to be unusable; 2. There are no remaining well slots or water wells on the developed gas field production platform When there are no remaining subsea wellheads in the lower production system, and it is impossible to add well slots or increase subsea wellheads, or the drilling and development directly from the established production platform or subsea production system cannot be realized due to economic and technical reasons, small-scale gas The stored reserves will not be available, and the country's precious natural gas resources will be wasted

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