Abstract:

Due to factors like gravity, laminar flow of oil, gas and water occurs in horizontal wells, which completely differs from the traditional vertical or slant wells.When applied to horizontal wells, the traditional fluid production profile interpretation method often produces errors.Thus it is imminent to create a new interpretation method for horizontal wells, so as to improve its interpretation accuracy and to enhance oil recovery. In this paper, we first analyzed the existing interpretation methods, and then describe the experimental results of horizontal well flow pattern mechanism.Our test data showed that the flow pattern remains constant when the tilt angle and the fluid parameters in each phase of the horizontal wells are the same.Yet a slight change in the inclined angle has great impact on the flow pattern.Therefore, we proposed an equal-tilt-angle interpretation model to calculate the flow rates of each phases in horizontal wells, designed an inversion algorithm, and programmed the model for calculation of fluid production of each layer.Comparative analysis with logging data from 22 wells showed that the error is less than 7.8% for single phase flow interpretation, less than 9.8% for multi phase flow interpretation, and less than 9.68% for total flow interpretation.Experimental results show that this interpretation method can improve the interpretation accuracy of fluid production profile in horizontal wells, and meet the requirements of engineering applications.

Key words: equal-tilt-angle, production profile, horizontal well, production logging interpretation