A new type of well pattern structure and method for heavy oil development in incineration reservoirs

Abstract

The invention discloses a novel in-situ combustion thick oil development well net structure and method. Two horizontal double-branch herringbone wells are used as production wells; two straight wellsare arranged above the middle of the two horizontal branched herringbone wells and are used as a gas injection well; two exhaust wells are respectively arranged above the outer side of the two horizontal double-branch herringbone wells. Each horizontal double-branch herringbone well comprises a vertical section and a horizontal section; a lateral branch is arranged in the horizontal section position. The two horizontal herringbone wells are in parallel arrangement; the two gas injection straight wells and four exhaust wells are parallel to the horizontal double-branch herringbone wells. The invention provides the arrangement of the branch well in the lateral direction of the horizontal double-branch herringbone wells, so that the area of the production well covering an oil reservoir can beincreased to a greater degree; meanwhile, the relative distance is precisely designed; the heat loss can be effectively reduced; the combusted gas and the nitrogen gas in the air can be exhausted byusing the exhaust well; the condition that a conventional in-situ combustion well network easily generates the gas over-covering phenomenon can be relieved; the thick oil reservoir yield is improved.

Description

technical field [0001] The invention relates to the technical field of oil and gas field development, in particular to a well pattern structure using four-branch fishbone wells as production wells and a row of vertical wells as injection wells. Background technique [0002] In-situ combustion, also known as fire flooding, or in-situ combustion, is a heavy oil thermal recovery technology with great potential, which belongs to thermal recovery technology. It uses partial cracking products of the oil layer itself as fuel, continuously burns to generate heat, and realizes intralayer combustion, so as to push formation crude oil from gas injection wells to production wells, and achieve the purpose of improving oil recovery. Fire flooding technology is accompanied by complex heat transfer, mass transfer process and physical and chemical changes, and has multiple recovery mechanisms such as steam flooding, hot water flooding, and flue gas flooding. The oil displacement efficiency ...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is: there is no exhaust well, once the combustion front breaks through from the horizontal well section, a large amount of crude oil in the area not affected by the combustion zone will not be recovered, forming a dead oil zone

Therefore, although this technology can improve the longitudinal sweep coefficient of fire flooding, it also faces the risk of a large-scale dead oil zone formed by the combustion front breaking through from the horizontal well.

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