A Case Study on the Effect of Production Segmentation Completion Technique PSCT and Inflow Control Devices ICD on the Optimization of Horizontal Well Performance

Alshmakhy, Ahmed (ADNOC) | Abdalla, Ruaa (ADNOC Onshore)



Horizontal wells have been drilled extensively in recent years where several challenges have been faced such as increased cost, short well life, limited accessibility, uneven stimulation, less productivity and water production. Although similar issues encountered in all reservoirs, tight reservoirs impose extra difficulty given their complexity and inherited limited productivity. In order to optimize flow profile and extend the life of horizontal wells, several techniques were implemented including Production Segmentation Completion Technique (PSCT) and Inflow Control Devices (ICDs).

Initially, a single well simulation study was conducted to determine and evaluate the effectiveness of using a dual completion string and ICDs in a horizontal well with open hole across a carbonate reservoir which generally suffering from rapid increase of water-cut due to high drawdown around heel. A review of literature and internal well cases were conducted to highlight the heel to toe effect and early water breakthrough issues.

As a result a novel multi-zones completion technique was proposed and implemented, this design comprises running a lower completion (LC) as isolation string and an upper dual completion, the hole heel will produce from the open hole (OH)-LC annulus through the short string (SS) and the toe will produce through LC through the long string (LS) stung-into LC. This design provided a method to choose the most appropriate horizontal section and demonstrated the value of having dual completions in terms of oil gain and water management as well as improved accessibility. This approach is then compared with the option of utilizing ICDs as a sophisticated method to control flow and manage production from different compartments of the openhole.

Field results supported the success of segmented completion project providing future opportunity to optimize the production configuration of horizontal wells. Thus, reducing number of wells and increasing production. Execution of this project increased production by about 1.3x versus single completion well, accessing deeper horizontal areas, with an optimized cost in addition to saving time. On the other side, inflow control devices were used extensively in industry with a large chance of success when planned well. On the simulation model, ICDs were added and different sensitivities were tried to decide on the best configuration.

Implementation of such optimization tools in early stages may be crucial to mitigate potential well issues that are difficult to cure later in well life. This complex and high profile project was executed against a background of limited time frame and resources. Project team demonstrated ability to adapt and succeed when presented by a truly unique challenge. A comparison study was essential to decide on best approach. To date, PSTC technique is the first to be implemented in UAE and the Middle East.