A COMPARATIVE STUDY OF PACKER INSTALLATIONS IN VERTICAL AND DEVIATED COMPLEX WELLS

The challenges of poor packer design, installation, performance, monitoring and evaluation increases from vertical to deviated wells due to complexity of the reservoirs and well completion method used. Non-availability of effective nodal analysis correlation with recent innovative packer installation designs leads to most technical failures. Non availability of accurate information such as number of packers, wellbore and reservoir characteristic behaviors triggers production uncertainties in vertical and deviated wells, and increases tendency for work-over operations. It also increases the cost of operations due to down-time and raises questions about the poor quality of installation design. The aim of this study is to investigate the impact of oil production due to different packer installation designs in vertical and deviated wells in a multilayered oil reservoir system in the Niger Delta using Schlumberger PIPESIM. The objectives are to design two (2) vertical and two (2) deviated well completion schematic models for a triple-layered oil reservoir network using single and multiple packer installations, to predict the different operating points of oil production rates and reservoir pressure using nodal analysis simulation sensitivities of all case studies, to carry out comparative sensitivity analysis and predict mathematical correlations of operating points as functions of the different case studies. The method used was to design four (4) case studies of vertical and deviated multi-layered oil well completion schematic systems using single and multiple packer installations at different reservoir thicknesses of 120ft, 168ft and 123ft for the upper, middle and bottom layers. These data were inputted and simulated with the PIPESIM software. Results of comparative sensitivity analysis of all models shows that the flow rates and reservoir pressures reduced for all well completion with vertical well simulations but increased for the horizontal wells. The maximum flow rate and pressure was obtained for case D with the deviated multilayered single packer installation design with approximate values of 14,937.70STB/day at 3,564.22psia. This shows that single packer installations are much favourable for either the deviated and/or vertical well. The predicted flow rate (Q) and pressure (P) models as function of the case studies (C) are; = . − . + +. and = .−.+.+. both with square regression coefficients of = . The major finding in this study is the technical observation that single packer installation designs in vertical and deviated wells increases oil production. This reason makes this research an appropriate technical evaluation resource, which will greatly enhance well completion design modeling even for more complicated wells, reduce down times and perhaps saves cost. It is recommended that further studies be done in economic analysis and technical evaluation of more complex wells to improve oil performance evaluation