Abstract:

During the development of reservoir with edge water, even if the water didn’t break through at the bottom of the horizontal well, the edge water incursion still influences the productivity of horizontal well. Based on the three- dimensional seepage field model of horizontal well, this paper divided the three-dimensional seepage field into two two-dimensional seepage field which are called internal seepage field and external seepage field respectively, used the methods of transformation of coordinates and conformal mapping to obtain the productivity formulas of the two two-dimensional seepage field, eventually got the new productivity formula of horizontal well considering the edge water incursion according to the principle of equivalent filtration resistance. Practical example shows that result calculated by new formula has small absolute and relative error with actual output, which indicates that the new formula is of high accuracy and good practicability. Sensitivity analysis demonstrates that productivity of horizontal well in consideration of edge water incursion is lower than that with no consideration of edge water incursion. Meanwhile, as the increasing of edge water incursion distance, the productivity of horizontal well decreased to a great extent with short horizontal section, while if the horizontal well length is long enough, the effect can be neglected. This study can provide a new solution to predict the productivity of horizontal wells during edge water incursion.

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