Intelligent Well Completions Performance and Reliability in the Northern Fields of Saudi Aramco
Authors: Al-Shammari Hatem H. 
Published: March 2015

Intelligent wells have become one of the best-in-class practices in the northern fields of Saudi Aramco with 153 intelligent wells equipped with downhole valve systems completed over the past 10 years. Different service suppliers approached the principle of producing through intelligent wells with their unique actuation mechanism and valve design. Therefore, many trail tests and piloting had been carried out prior to the mass installation of any system to ensure its reliability, functionality and operational suitability. Subsequently, the experiences gained from the operation of the installed intelligent wells over the past decade provided a whole new perspective into their operability, applicability and added value.

This paper reflects on the experiences gained from the operation and maintenance of the installed intelligent wells through:Comparison between the performance of different downhole valve's actuation mechanisms used in the northern fields of Saudi Arabia with provision of their pros and cons.Identification of their operational impact and suitability for a specific application environment.Illustration of their components and the overall system's reliability with logged surface and subsurface failures along with their impact on the well performance.Suggestions to select the most appropriate intelligent well system to withstand normal as well as harsh environments while serving the production objectives.

The paper also provides valuable recommendations to alleviate the operational and maintenance issues often encountered during the actuation of downhole valves.

Introduction

Once the horizontal well concept was introduced to the oil and gas industry, a new era of placing the hydrocarbon producers had begun. It mainly helped in mitigating and delaying the production of undesirable fluids. Moreover, limited logistics such as those in an offshore environment, and the need for further reduction in development cost led to drilling and producing through multilateral horizontal wells. Consequently, the placement of laterals in different reservoirs or even the same reservoir imposed a new challenge as it exposes each lateral to different reservoir conditions. These conditions, such as significant variation in reservoir pressures, zonal productivities, gas and water fractions, and permeability, disturb the contribution balance between the laterals of a multilateral well1. There was no telling how these laterals would interact or affect each other once on production, especially in the case of breakthrough of undesirable fluids. This triggered producing through intelligent wells equipped with downhole valves, which allowed different laterals to produce in harmony. The downhole valves of an intelligent well are located at the entry of each lateral to the production tubing. This enables opening or closing the flow at each entry. On top of that, each downhole valve can be designed with the feature of producing at different predetermined choke positions since simply having a downhole valve that just can be either opened or closed (binary valve) would serve a very limited purpose. These downhole valves of an intelligent well are more commonly known as inflow control valves (ICVs). These ICVs are operated from the surface by means of cables that are strapped and run on the outside of the tubing to form the downhole ICV to the surface panel.