Low Permeability Reservoir Reasonable Well Density Study

The question of determination of rational pattern size is a hot and long-term discussion topic in oil-field development area. Regardless of has began or before the official investment development, all must carry on the proof to the pattern size. The pattern size relates directly to the well spacing to the oil reservoir water drive controlling degree and the water drive recovery, thus it affects on the development effect of oil reservoirs directly, at the same time it is also very important to the oil field economic efficiency. If the rational pattern size to the common and high permeability oil reservoirs is the significant matter of principle, then regarding the low permeability oil reservoirs,it will say that the pattern size is the success or failure matter crucial question.As for the low permeability oil reservoirs, its essential feature is which owns the start-up pressure gradient, its controlled area is smaller than by far the conventional high permeability oil reservoirs, namely between oil wells and injection wells, between oil wells and oil wells, if the pattern size deployment is unrational, it will arisen massively by-passed oil area in which pouring water cannot affects to and the oil well cannot be produced , even could cause that the oil well's production large scale to drop continued, but the corresponding injection wells stratum infiltration capacity drops suddenly, addition to the plane and hangs anisotropic, the light with the macroscopic empirical formula calculating the pattern size is by far insufficient, Because obtains based on the Shirr formula union economic analysis computation, the pattern size not necessarily conforms to the low permeability oil reservoirs' actual situation, also not necessarily conforms to the one which can satisfy the rational development needs.First of all, using the rational pattern size of low permeability oil reservoirs first must resolve the contradiction -"high-injection pressure and low-production pressure ", but on the other hand the pattern size based the empirical formula by which water drive recovery and the pattern size relations established only can be used under the technical limit pattern size support, and it says that the rational well pattern density is the one which can obtain the high recovery ratio and the economic efficiency as far as possible, according...