A Method for Evaluation of Water Injection Development Effect in Fracture-vuggy Reservoirs

Abstract

The invention provides a fracture-vug type oil reservoir water-flooding development effect evaluation method. The fracture-vug type oil reservoir water-flooding development effect evaluation method comprises the steps that fracture-vug units to be evaluated are divided into a plurality of injection and production well sets; the well control coefficient of each injection and production well set is calculated, and the well control effect interval of each well set is determined combined with a corresponding preset well control coefficient index; the water-flooding recovery efficiency and the oil exchange rate of per ton water of each injection and production well set are calculated, and the development effect interval of each well set is determined combined with a corresponding preset development coefficient index; the cumulative water content and the water storage rate of each injection and production well set are calculated, the judging that whether water channeling exists or not is performed according to the cumulative water content, a water storage effect interval is determined combined with a preset water storage rate index; the non-dimensional flexible yield ratio, the single reservoir pressure drop and the artificial water-flooding index of each injection and production well set are calculated, the natural energy interval of each well set is determined combined with a corresponding preset natural energy index, a water-flooding effect interval is determined combined with a preset artificial water-flooding index. The fracture-cavern type oil reservoir water-flooding development effect evaluation method fully reflects the water injection effect of the injection and production well sets and the reason of achieving the effects, and therefore the foundation and the basis and the pertinence of the provided adjustment measure are better achieved.

Description

technical field [0001] The invention relates to the technical field of water injection development of fracture-cavity reservoirs, in particular to a method for evaluating the effect of water injection development of fracture-cavity reservoirs. Background technique [0002] At present, there are many disadvantages in the water injection development technology of reservoirs. For example, most blocks of Tahe fractured-cavity carbonate reservoirs have implemented water injection to replace oil and fracture-cavity unit water injection development, and achieved good results. The yield is only 13%-15%. The water cut in some injection-production units has risen seriously, and it is gradually becoming more difficult to stabilize oil production and control water. It is necessary to continue to deepen the water injection work and take appropriate adjustment measures to increase production and efficiency of old wells and improve reservoir recovery. yield. Therefore, it is necessary to ...

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Problems solved by technology

[0004] However, because fractured-cavity reservoirs are different from conventional sandstone reservoirs, the space of reservoirs is discretely distributed, and there are large differences in the size and shape of fractures and caves in different parts. Reservoir not applicable

However, the research on water injection development of fractured-vuggy reservoirs mainly focuses on the research on water injection methods based on experience, lack of research on the evaluation of water injection effect, and the research on the evaluation of water injection effect is quite difficult, which is manifested in the following aspects: ( 1) The distribution of reservoirs and the relationship between injection and production in fractured-vuggy units are complex, and it is difficult to effectively determine or divide the injection-production well group, and the injection-production well group is taken as the basic research object; (2) The internal connectivity of reservoirs in different injection-production well groups is complicated , The matching relationship of fracture-cavity well patterns is various, and the natural energy sources are different; (3) The production dynamics of different injection-production well groups are highly individualized and poor in comparability; (4) The existing water injection development decision-making only relies on past experience and lacks effective theories (5) Currently there is no technical method system for the evaluation of water injection development effects in fractured-cavity reservoirs, resulting in the inability to carry out water injection adjustments and lack of guidance for the formulation of follow-up adjustment measures

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