Longitudinally superposed developing two-strata oil reservoir well pattern, and arrangement method of two-strata oil reservoir well pattern

Abstract

The embodiment of the invention discloses a longitudinally superposed developing two-strata oil reservoir well pattern, and an arrangement method of the two-strata oil reservoir well pattern. The method comprises the following steps: firstly determining the longitudinal development strata of the oil reservoir and the rational well distance, and determining the well spacing of a basic well pattern and the well spacing of a middle transitional well pattern according to the longitudinal development layer coefficient. According to the longitudinally superposed developing two-strata oil reservoir, the well spacing of the basic well pattern is 2L, after being encrypted once, the well spacing of a middle transitional well pattern is square root of 2 times L; after being encrypted twice, two superposed well patterns with a well spacing of square root of 2 times L are formed; the well spacing of the superposed well pattern after alternative strata development is L; the evolution process of the well spacing is as follows: 2L to 2 times square root of 2 L to L; the conversion middle process of a well pattern with a well spacing of square root of 2 times L; in the same drilling speed, well placement uniformity coefficient and reserve control speed are increased; the well spacing is encrypted in the alternation of well patterns; each well pattern can realize order development to each strata; the utilization ratio of the well patterns is improved; and meanwhile, the oil reservoir is uniformly used, so that the method is in favor of increasing accumulated oil production of an oil field and improving the recovery ratio; and interlayer interference generated by extracting oil in multiple oil layers of longitudinal series of strata is avoided.

Description

technical field [0001] The invention relates to the design of oilfield development deployment and adjustment schemes, in particular to a vertically superimposed and developed two-layer oil reservoir well pattern and a deployment method thereof. Background technique [0002] At present, three well pattern deployment methods are usually adopted for the water flooding development of vertically superimposed multi-layer reservoirs with a single oil layer thickness of more than 4m and crude oil viscosity lower than 10000mPa.s: one is to deploy a well pattern for each set of layers A set of well patterns (wells with different formations at the same location and the same well site) are independently developed. The second is to use a set of well patterns to develop layer by layer. The third is to use a set of well patterns to jointly mine all vertical formations. [0003] Most of the well pattern deployment and adjustment methods used in oilfield development are reverse nine-point me...

AI Technical Summary

Problems solved by technology

For vertically superimposed multiple layers, a set of well pattern is commonly used to recover layer by layer, and all wells are drilled to the lowest layer of the reservoir. The disadvantage is that the production layer is single, and multiple oil layers in the vertical direction cannot be used at the same time. , the oil recovery rate is low, and the development efficiency is low; another commonly used method is multi-layer commingled production, the disadvantage is that it does not consider the difference between vertical layers, which leads to interlayer channeling and interference, which affects the development effect; Multiple wells are drilled in the well site, and each set of layers has a separate well pattern, such as figure 2 As shown, it is a schematic diagram of a set of well pattern intensification and adjustment method deployed in the same well site for each set of vertically stacked multi-layer reservoirs in the prior art, where (a) is the reverse nine-point basic well pattern; (b) is Inverse nine-point infill well pattern; (c) five-point infill well pattern

The development wells of each set of strata are only drilled to the corresponding development target layer, the disadvantage is that the number of wells drilled is twice that of the previous two well layout methods, the investment cost is high, and it is not economical

[0004] It can be seen that in the process of developing vertically superimposed multi-layered reservoirs with the above three well layout methods, the vertical layers cannot be taken into account at the same time. Well pattern development has many limitations such as too many wells drilled, large investment, low utilization rate of well pattern, poor economic benefits, etc.

Images