A Novel Approach for Production Stimulation through Chemical Applications in A Saudi Arabian Offshore field
Authors: Balto Abdulelah A. , Qahtani Hassan B. , Sukkar Luai 
Published: March 2015

This paper includes a discussion of a progressive approach and recent practices to stimulate wells in one of Saudi offshore fields. A chemical treatment pilot aimed for production enhancement was recently conducted and proven successful in an offshore environment while recognizing merits associated, including fluid placement optimization in terms of logistics and time beside treatment effectiveness. Implementation of such practices has increased chemical treatment success rate, enhanced well production performance, reduced cost and improved operational HSE practices.

The recent chemical treatment applications and practices were the outcome of five years of dedicated search and collaboration with service companies to find the most effective chemical recipes and their deployment method. The campaign was initially piloted in three different wells completed with inflow control devices wrapped with premium screens, using three different chemical applications while utilizing a distributed temperature sensing (DTS) technology for the first time in an offshore field to evaluate treatment effictiveness.

Initially, three wells were completed in high permeable and contrasted sandstone layers. Those wells are completed with sandstone screen completions coupled with inflow control devices to control sand production while providing a degree of production management across the producing lateral. The completion practice prior to the pilot did not allow an efficient cleanup due to HSE and operational considerations. Extensive technical, operational and economical evaluations were conducted to ascertain the best chemical recipe, fluid placement technique, equipment and applications used to ensure the proper treatment exposure to the damaged zone for better production output results.

Horizontal completion practices have changed; hence new challenges have arisen to consider for instance the best contemporary placement technique used for treating fluids in different type of horizontal completions. Long horizontal sandstone producing laterals in the past, which used to be completed as cased and perforated are being completed as open hole laterals with inflow control devices coupled with screens where the fluid placement technique must vary to account for best and uniform treatment coverage. This paper will include the pilot results and recognized merits. Offshore production engineering insights will be also shared in this paper.

Introduction

The first chemical treatment experience in offshore sandstone fields in Saudi was in 2005 with a limited success especially in "S" oil producing field. Search for better recipe resulted in identifying three chemicals; M1, M2 and M3. The chemicals were tested extensively by a specialized formation damage laboratory. Moreover, a further search for excellence with Inflow control devices manufacturers revealed that bullheading of such chemicals at high rates in wells with screens will have a better chemical distribution along the producing compartments. To complement this unique approach, effective logging while bullheading was achieved by a distributed temperature sensing coiled tubing (DTS-CT string) string to show the zonal chemical placement and identify any thief zone. This cutting edge technology, which was used previously in Saudi Arabia has led to a significant chemical consumption optimization that is being recognized as an international record with outstanding results. From the three treated wells in the "S" field, the bullheading technique was confirmed by the DTS-CT as superior to pumping through conventional coiled tubing in wells completed with inflow control devices.