Application of Odeh and Babu strategies for determination of flow periods in a horizontal well in a bounded reservoir

Abstract

A bounded reservoir in the first instance possesses the double potential of transient and boundary dominated effects of flow on a production well. In a horizontal well, as in the vertical well, the transient flow period occurs during the early life of the well at which time the reservoir boundary has no effect on the well performance. In the later life of the well, near or at the boundaries, a number of flow periods develop, with special effects of the reservoir on the well performance. Many methods have been used to predict or identify the flow periods in a well. For horizontal wells in particular, Odeh and Babu techniques have suggested a strategy for achieving flow periods identification for a horizontal well in a bounded reservoir. In the strategy, only major flow periods occasioned by effects of the individual boundaries are predicted. The transition periods are not clearly identified. In this work, all the flow periods, including the number of transition periods, are identified for several cases of reservoir external boundaries and horizontal well designs. Results show that a mandatory infinite-acting (radial flow period) initiates any flow in all cases of reservoir geometry, boundaries and well designs. Furthermore, there can be as many as five major flow periods and four transition flow periods for an isotropic reservoir case considered throughout the study. The number of flow periods are affected by the reservoir boundaries, geometry and wellbore design. Again, results further show that the number of successive flow period increases with horizontal well length as dictated by wellbore radius.