THE PRODUCTIVITY OF WELL PATTERN WITH HORIZONTAL WELLS AND VERTICAL WELLS

摘要

The calculation of productivity and the choice of well pattern of mixed horizontal and vertical wells were discussed in this paper. Because the naturall drainage areas of horizontal wells are oval rather than circular, rectangular drainage well patterns should be adopted. Using pseudo 3-di-mensional method and conformal transformation, the potential function of a row of horizontal wells was deduced. Using this function and the superposition principle, an analytical solution of the productivity for the rectangular mixed well pattern was given. Quantitative means for defining the shapes of the optimum pattern were developed in this paper by introducing two dimensionless parameters, the shape factor and dimensionless length of horizontal well. The formula for productvity was used to optimize the mixed well patterns. The curves of the optimized shape factor against dimensionless length of horizontal well were drawn. The results show that the pattern area and formation thickness have no effect on the optimal shape factors and can be applied to the design of development for oil fields.