The paper discusses several issues related to the interpretation of transient pressure tests on horizontal wells. Horizontal well type curves incorporating the effects of wellbore storage and skin are used to aid in the diagnosis of and estimation of parameters from test data. Issues addressed in this study include the identification of flow regimes. validity of Horner graphs. and analysis of multirate tests. An example interpretation is discussed to illustrate concepts.
It is shown that for other than the most ideal situation, the early radial flow behavior will not be evident. In tests with short flow or buildup periods, it is possible for wellbore storage and skin effects to mask both the early radial and linear flow periods. Where early radial flow is present, it is shown that as long as flow length is very long compared to shutin time, a Horner plot may be used to compute formation parameters.
In the general case. type curve matching procedures provide adequate means for estimating the desired parameters from the well test.