How Malfunctioning Completion Accessories Affect Well Performance Offshore Saudi Arabia

Abstract

To overcome horizontal well reservoir and production challenges, inflow control devices are adopted as the optimal completion method in many parts of the world.  The main industry drivers for adopting inflow control device completions include balancing inflow along the well, delaying water and gas breakthrough, controlling water and sand production, and providing a cost-effective reservoir completion solution to meet the majority of the reservoir challenges. In offshore Saudi Arabia, inflow control devices have been used successfully in fulfilling these objectives. The downhole completion efficiency is evaluated using multiphase production logging tools.

Many completion accessories can be run with inflow control device completion strings, these include isolation packers, liner hangers, setting tools, end-of-completion string plugs and valves. All of these accessories may affect the well’s production performance. New challenges arise when one of these accessories, such as the end-of-completion valve or isolating packers malfunction and develop a leak; thus, affecting the inflow control device completion performance. A major failure can result from such a malfunction, including fluid drainage from the toe section, sand production, early water breakthrough and water coning.

This paper presents two field examples in which multiphase production logging profiles of horizontal wells are used to evaluate the inflow control device completion performance and detect any completion-accessory malfunction. Multiple sensitivity simulation runs — supported by multiphase production logging results — facilitate optimizing the inflow control device completed well performance. This integrated approach is used to recommend solutions or remedial actions to overcome sub-optimal well completion performance. Also, the approach provides a comprehensive understanding of the reservoir results that should be considered in planning future completion and workover strategies.

Introduction

Hydrocarbon demands continue to drive production, particularly among assets in offshore reservoirs. Horizontal wells produce fluids by nonuniform inflow due to reservoir permeability/pressure variations along laterals, frictional effects along the wellbore, and sand production. The nonuniform inflow promotes early water/gas breakthrough. These wells are completed  using inflow control devices (ICDs) with screens to optimize the well performance and overcome the main field challenges, namely formation damage during drilling by better cleanup processes, pressure loss due to heel-to-toe friction, and sand control.