Interpretation of the Skin Factor for Predicting the Perforation-Induced Formation Damage in Reservoirs

Abstract

This study has established that permeability is decreased in the range of 30%-75% due to the implement of the conventional method of perforation by shooting (PS) technique compared to the openhole completion. As a result, a new perforation technique called perforation by drilling (PD) has been proposed in this paper. To simulate a perforated completion, cylindrical sand samples (0.0572 m OD) with varying strength and porosity were prepared. These samples were perforated (0.0136 m ID) by the PS, PD and Casting techniques. Perforations created by the Casting techniques are considered the ideal openhole perforation tunnel. An important measure of flow efficiency or productivity of perforation completions can be referred to as skin factor (s). In this paper, the performance of the PS, PD, and Casting technique was measured in terms of skin factor. Experimental results show that the s in the PD and PS techniques is 0.20 and 17 respectively, for the ratio of rd/rp is 1.5. Thus, in terms of inflow efficiency the PD technique is superior compared to the PS technique.