First Design of Inflow Control Devices Completion in Offshore Khafji Field Sandstone Reservoir: Challenges and Application
Authors: Moawad Taha Mousrafa , Salah Mohamed , Al-dhafeeri Abdullah , Mohammed Tawakol Ibrahim , Abd Elfattah Mahmoud Mohamed 
Published: June 2014

First application of Inflow Control Devices (ICDs) completion is implemented in long openhole section with an average permeability of 3000 md sandstone-reservoir in offshore Khafji field. This work illustrates the best evaluation to design and to select the process for using ICD in long openhole section of 1,900 ft.

The present paper discusses the challenges which faced to install the first ICD completion focusing on reservoir/production challenges including heel-to-toe effect, uneven drainage across horizontal section, early water breakthrough from high permeability intervals, water coning / fingering, sand production and hole stability issues. The second challenge category includes drilling fluid selection with heavy weight drilling mud due to hole stability issues and chemical treatment process.

Cleaning of water -base mud filter cake at ICD completion by using a treatment fluid that will attach to the mud cake to be lifted up in order to disperse all the mud particles passing through the screen will be discussed in this work. The treatment combines chelating agent and enzyme breaker; such treatments ensure removal of both polymer components and CaCO3 bridging particles in the mud filter cake as single step. Laboratory test results and fluid preparation will be discussed in details later.

The initial well testing result showed a successful completion deployment of ICD in a long openhole section to TD with high production rate and zero water cut. Well production performance will be compared with offset wells to evaluate ICD completion value in terms of reservoir and production optimization.

Introduction

ICD completion technology has been widely used in oil fields with high rate of success worldwide during the last decade. This technology added a great value in terms of balance horizontal intervals fluid influx, delay water breakthrough and control water production for heterogeneous reservoirs (1–13).

The main purpose of installing ICD completion is to provide an uniform inflow influx profile across the target zones through restriction the high permeability flow zones which enable low reservoir quality zones to produce more; this way minimize the contrast in fluid influx profile and balance the flow. ICD has deployed in oil wells especially in long horizontal or lateral wells as openhole completion aimed at distributing flow rate from intervals evenly. The inflow rate can be varied to its completion length based on the heterogeneity of the reservoir and the frictional pressure. The oil recovery and sweep efficiency might negatively affected by the variations in inflow rate across well horizontal section. The reservoir heterogeneity plays a substantial role in designing the ICD corresponding to the inflow rate and the productivity index to the well characteristics. Therefore, the flow distribution around the wellbore can be substantially affected by reservoir properties heterogeneity (permeability, reservoir pressure, fluid saturation, ….); well production target rate, and frictional pressure (14–22).