Research On Well Layout And Development Optimization Of Volcanic Reservoirs In Xinjiang

The fractured volcanic reservoirs have the characteristics of extremely low matrix permeability,complex lithologic and facies,development of natural fractures,development of edge water in some blocks,and large longitudinal thickness of oil layers.Due to the repeated tectonic movement during the hydrocarbon accumulation process,a large number of natural cracks are developed,which leads to water's breakthroug in the process of water injection development.Reasonable well layout and development methods are particularly important.In this paper,the control radius of fractured volcanic reservoirs is analyzed theoretically.The relationship between cross-flow coefficient,elastic energy storage ratio and well control radius is studied respectively.The seepage radius of fracture seepage stage is analyzed from the perspective of theoretical formula and estimated its size,which providing data support for well network deployment.At the same time,the best vertical well spacing and horizontal well spacing are calculated from the economic limit,and draw the corresponding plate.Secondly,the development effects of vertical and horizontal wells are evaluated for different crack inclination angles,and thus getting guidance about well type and well spacing selection in volcanic reservoirs.Different volcanic reservoirs have different natural energy sizes,so different volcanic reservoirs adopt different development methods.At present,water flooding and natural energy depletion are two main development methods.For water injection development reservoirs,water-driven three-dimensional injection-production structure is firstly selected.On this basis,different development well patterns were designed,and then the optimization of the three-dimensional injection-production well pattern was carried out,and the parameters of the well spacing and row spacing of the well pattern were optimized.For natural energy development reservoirs,reasonable vertical well pattern is more important,and compared with the development effect of vertical horizontal well combination well pattern,the final development results show that the former is better.Finally,the actual block numerical simulation of the volcanic reservoir in the CH-478 well area near the crater phase was carried out,and three different development plans were designed.Among them,the development of the first plan was the best.By combining the previous deployment methods and development optimization research,the development effect was improved and the reference for the actual development design.