Determining method for distance of well-drain and length of pressure break of low penetration oil reservoir artificial fracture

Abstract

The invention provides a determining method for a distance of well-drain and the length of a pressure break of low penetration oil reservoir artificial fracture. The determining method comprises the following steps of first, establishing a well yield formula under a non-darcy flow condition, second, establishing water drive sweeping efficiency calculating formula of different well patterns under the non-darcy flow condition, third, drawing matching plates of different well distances, well-drain distances and pressure-break lengths of a target oil reservoir based on the water drive sweeping efficiency calculating formula, and fourth, evaluating a reservoir stratum use condition of the reservoir stratum, optimizing the well-drain distance and optimizing the matching pressure-break length according to the matching plates of the different well distances, well-drain distances and pressure-break lengths in the third step. Optimized combination between pressure-break half length and the well-drain distance can be achieved when water drive sweeping efficiency and economic and rational well-drain distance of the target oil reservoir are determined; and the method requires less parameters, quick calculation and strong application.

Description

technical field [0001] The invention relates to the technical field of oilfield development, in particular to a method for determining the fracture length and well row spacing of artificial fractures in low-permeability reservoirs. Background technique [0002] The low-permeability reservoirs in the Shengli Oilfield are rich in resources, but the quality of the reservoirs is poor (large burial depth, poor reservoir physical properties, small pore throats, and thinner reservoir thickness), which presents a situation of low single well productivity and low water injection capacity. Artificial fracturing method to improve single well productivity and injection capacity. However, in the process of water injection development, due to the lack of a systematic adaptation and optimization method for artificial fractures and well spacing, the development effect is limited to varying degrees. For example, Shengli Oilfield has carried out water injection development tests in low-perme...

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Problems solved by technology

[0002] The low-permeability reservoirs in the Shengli Oilfield are rich in resources, but the quality of the reservoirs is poor (large burial depth, poor reservoir physical properties, small pore throats, and thinner reservoir thickness), which presents a situation of low single well productivity and low water injection capacity. Artificial fracturing method to improve single well productivity and injection capacity

However, in the process of water injection development, due to the lack of a systematic adaptation and optimization method for artificial fractures and well spacing, the development effect is limited to varying degrees

For example, Shengli Oilfield has carried out water injection development tests in low-permeability beach-bar sand reservoirs such as Liang 4 Block, Liang 8 Block, and Fan 144. However, due to the poor matching between artificial fractures, well spacing and rejection, the oil wells are slow to produce results after water injection. The efficiency is only 52%, the degree of effective use is low, and the development effect is poor

In the past, the optimization of artificial fracture adaptation was mainly based on empirical judgment, which was highly subjective and lacked clear, reliable and scientific operation steps.

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