Open Cell Matrix Polymer (OCMP) Filter Solution for Through Tubing Remedial Sand Control - A Case Study of Malaysian Oilfield

Background The South Furious field is located about 220 km NE of Labuan Island on the North Sabah continental shelf in water depths of between 60 and 200 ft. The field is comprised of two culminations separated by a large displacement fault. The western culmination was discovered in 1974. The eastern culmination was discovered in 1975. Reservoir type is Estuarine and Coastal/Alluvial Plain sandstones Mid Miocene Stage IVA. The field is comprised of thick successions of thin, heterogenous, interbedded sands and shales with complex faulting and uncertainties around well by well correlation. The main hydrocarbon interval depth is between 1,500 to 4,900ft-TVDSS. The field has gone through seven development stages since the first oil production in 1979. The initial understanding was that reservoir sands shallower than 3,000ft TVDSS required downhole sand control. Downhole sand control application has evolved due to lessons learned from previous stages of development. The method selected was primarily based on the formation sand properties according to criteria as per industry standard and also based on learning from historical sand control performance. Initial completion design was cased hole gravel pack (CH-GP) for shallow reservoir sands (above 3000 ft TVDSS) and cased and perforated for deeper reservoir sands (below 3000 ft TVDSS). In one of the subsequent developments, due to cost optimization, the completion design was changed to cased hole with expandable sand screens (CH-ESS) for shallow reservoir sands and cased and perforated for deeper reservoir sands. With more wells in production, it came to be understood that the entire reservoir required sand control and not just the shallow reservoir sands. Consequently, the following development changed completion design to CH-ESS for all perforation intervals. Due to hot spotting issues, most of the ESS in the shallow reservoir sands failed and caused severe sand production to surface and accumulation in the tubing and casing. Most of the shallower production zones were shut in entirely to control sand production. This is the type of completion that will be discussed further for application of OCMP filter for remedial through tubing sand control. Completion designs for more recent developments were changed to open hole with ESS (OH-ESS) and then later changed again to open hole with standalone screen (OH-SAS) for cost optimization and based on the failures observed in the CH-ESS sand control. Open hole with SAS seems the most cost-effective sand control solution for new wells for this field, however many legacy wells require remedial through tubing sand control which can be installed through well intervention to avoid costly well workovers as the field production continues to decline.