关键词: 低渗透油藏, 整体压裂, 井网优化, 不规则井网, 数值模拟

Abstract:

A new well pattern design model was built that can be applied to not only normal but also complicated fault-block low permeability reservoirs, the largest sweep area of fracturing and the highest recovery were target parameters for the optimization design by the model, and the effect of the irregular aligned fracture orientation on the well pattern design was fully considered. A reservoir numerical simulation was applied to optimizing parameters of fracturing wells by mean of selecting a well pattern allocation scheme that combined various factors together, such as higher degree of reserve recovery, higher average crude output of individual wells, and lower composite water cut of reservoirs. Consequently, an optimum scheme combined by well-pattern types and fracture parameters that fitted the reality of reservoirs was obtained. Moreover, effects of the maximum horizontal principal stress orientation of strata and the single-well elliptical drainage area on the well pattern design were systematically studied. The research focused firstly on both the irregular well pattern and an integral fracturing development plan for complicated fault-block low permeability reservoirs, which further improved the design concept of integral fracturing development plans for low permeability reservoirs. This approach had been successfully applied to the integral fracturing development plan for Block A(a normal low-permeability reservoir) in the Daqing Oilfield and some complicated fault-block reservoirs in the Bohai Bay Basin, and a better production benefit was gained from the both. Therefore, this approach is of instructive significance in promoting the design level of integral development plans for low permeability reservoirs.

Key words: low permeability reservoir, integral hydraulic fracturing, well pattern optimization, irregular well pattern, numerical simulation