Next-Generation Production Control Aids Multiple Dipping Sandstone Reservoirs
Authors: Wilson Adam 
Published: February 2015

This article, written by Editorial Manager Adam Wilson, contains highlights of paper SPE 145854, ’Implementation of Next-Generation Intelligent Downhole Production Control in Multiple Dipping Sandstone Reservoirs, Offshore East Malaysia,’ by J.H. Chris Chen, SPE, N.M. Azrul, B.M. Farris, K.Z. NurHazrina, M.K.M. Aminuddin, and M.Y. Saiful Anuar, Petronas Carigali, and K.F. Gordon Goh, SPE, K.S. Premjit Kaur, T.K. Darren Luke, and A. Eddep, Schlumberger, prepared for the 2011 SPE Asia Pacific Oil and Gas Conference and Exhibition, Jakarta, 20-23 September. The paper has not been peer reviewed.

A next-generation intelligent-completions system was implemented successfully in a complicated, highly dipping, multilayered sandstone reservoir with commingled production. In this multizonal production solution, the conventional surface-controllable downhole zonal flow-control valves are now integrated with data-surveillance gauges, intelligent sensors, and isolation packers into one completion joint, compared with the previous multijoints system (i.e., splicing of up to three joints per zone required conventionally). This single modulated joint system has reduced installation time substantially compared with conventional intelligent-completions installations. The risk of surface completions makeup damage before running in hole is also greatly reduced with fewer connecting components.

Introduction

The S field offshore East Malaysia consists of multiple dipping heterogeneous sandstone reservoirs with unconsolidated formation (Fig. 1). These multi-stacked reservoirs have an overall 40-m-thick oil column with margin-al oil initially in place (OIIP). A large gas cap (i.e., twice the OIIP equivalent) also exists.

Because horizontal wells are recognized as one of the more productive development options in exposing wellbore to maximum reservoir con-tact and drainage area for recovery economics, the decision was made to drill 14 horizontal wells for the first batch of field development. This development option has reduced the number of well counts significantly while maximizing reservoir-drainage points, thus making the project economics for developing this marginal field greatly improved.

Two of the 14 horizontal producer wells in this marginal field have been screened to apply the modular integrated-intelligent-completions system (IICS) to actively control and permanently monitor zonal inflow for optimal production.

Developing a Thin-Oil-Rim Field Intelligently

The downhole active-flow-control-solution application in the horizontal well was one of the selected strategies to complete wells in these complicated geology structures while enabling zonal-contribution adjustment and future zonal selectivity. This is an intelligent alternative zonal management option compared with the other passive version of the inflow-control-device applications in the same field. Out of the eight commingling producers analyzed, two oil producers (i.e., Well-A1 and Well-A2) were selected as potential candidates for the intelligent-completions design. The significant zonal-reservoir-deliverability contrasts for Well-A1 and Well-A2 proved suitable for an initial zonal-influx balancing and later reactive inflow solution.