A Study On Optimized Combination Between Well Pattern And Hydraulic Fracture System In ZJ60 Block

The economic and high efficient development of reservoir with low permeability has to use hydraulic fracture technology. Because a piece of support fracture with certain orientation, length, conductivity will be formed in formations after hydraulic fracturing, and some characteristics different from general reservoirs (without hydraulic fracturing) will appear in the course of production. Length of fractures, conductivity and orientation will alter porous flow mode, drainage areas and swept efficiency in wellbore areas and ultimately affect oil well production and recovery. If we can reasonably lay out well pattern of low permeability and make it match up with hydraulic fractures, and will achieve good fracture action of enhancing production. Otherwise, unmodified development contradictions will appear in the late development stage and limit development level of low permeability. Therefore, the author took Jingan low permeability oilfield as example and studied optimized combination between well patterns and hydraulic fracture systems in this paper. Based on full understanding of reservoir characteristics and stress orientation and applying many methods such as numerical simulation .fracture simulation ,and economic evaluation, this paper studied the influences of optimized combinations between three types of well pattern and different hydraulic fracture systems, namely square well pattern of inverse nine spots, modified well pattern of inverse nine spots and rectangle well pattern, on oil well production, water-cut, recovery andeconomic benefits, and discussed the distribution of pressure field and saturation field, analyzed adaptability between well patterns and hydraulic fractures. The results are presented as follows.1. Based on domestic present development situation of low permeability oilfield, we formulated a new concept of optimized combination between well patterns and hydraulic fractures. That is hydraulic fractures affects must be considered when laying out reservoir development scheme, and hydraulic fractures must match up with well pattern, and then we can enhance well productivity as possible.2. We simulated the changes of production, recovery percent, net cash with time under the different combination conditions, and analyzed different combinations advantages and disadvantages, namely the combinations of three types of well pattern with different hydraulic fractures. (Square well pattern of nine spots, modified nine spots well pattern and rectangle well pattern). By study ,we find that the rectangle well pattern along fracture favorable orientation is suited for Changqing oilfield and break the accustomed model of inverse nine spots well pattern in development of low permeability.3. We studied the distribution of pressure field and saturation field under different well patterns ,and discussed1 profound reasons why rectangle well pattern is fit for low permeability reservoirs.4. The study on optimized combination between well pattern and hydraulic fracture systems provide a new idea and method for economic development of unemployed reserve and some study conclusions can offer basis for development management of low permeability oilfields.