Document Type : Regular Article


1 Metu-Northern Cyprus Campus

2 The University of Technology, Baghdad, Iraq


This paper focuses an insight on the impact of well spacing on the performance of oil and gas reservoirs depleted by multiple horizontal wellbores distributed parallelly or radially in rectangular and circular drainage areas. The objective is to develop an integrated approach for predicting the pressure, flow regimes, flow rate, cumulative production behavior, and estimating the transient and stabilized pseudo-steady state productivity index. The motivation is eliminating the uncertainties in predicting these key parameters that are importantly used in the development plans of the reservoirs.

The outcomes of this study can be summarized in the following points: 1) Well spacing does have a significant influence on the performance of all reservoir configurations, however, it is not seen at early production time while it is very clearly observed at late production time. 2) The impact of well spacing on radially distributed wellbores at circular drainage areas is more than parallelly and radially distributed wellbores in rectangular reservoirs. 3) The well spacing causes a well interference that could be characterized by developing a new flow regime called early pseudo-steady state flow that is typically followed by a transient state flow regime. 4) The well interference could be seen early when the well spacing is narrow. It could be observed during intermediate production time. 5) The pressure drop and the productivity index may change significantly after the well interference more than before.