Conforming Production Logging Tool with High-Resolution Electrical Imager in Carbonate Reservoir

Abstract

Abstract This paper presents results from integration of Production Logging Tool (PLT) data with image facies interpretation from high-resolution electrical images in a horizontal producer well in Kuwait. The Minagish Oolite Formation is a carbonate reservoir in the Umm-Gudair field which is characterised by packstone to grainstone with oolitic rich facies. Integration of fluid contribution along the producer hole from PLT measurement with image facies from electrical image logs will support completion strategy optimization. A PLT was deployed in horizontal producer well of 6.125 inch (bit size) with coil tubing, when both flowing as well as shut-in conditions with choke size (128+128)/64″. Liquid rate from PLT 2981 Barel fluid per day (BPD) was in agreement with surface Portable Gas Oil Ratio (PGOR) test rate (2975 BPD). During drilling, high-resolution of electrical image was acquired. The electrical image has range of conductive (darker) and resistive (brighter) features, where conductive image shows porosity such as vugs and resistive image shows less pore space such as cemented patches in carbonates. Based on PLT measurement, entire producer section was divided into six intervals, as below Interval A has 800 feet and interval E has 150 feet with production rate 56 BPD.Interval B has 300 feet which contributes 80 BPD.Interval C contributes 100 BPD and has 75 feet lateral section.Interval D has 300 feet lateral and contributes 92 BPD.Interval F contributes maximum liquid of 2590 BPD from 1350 feet interval. On integrating PLT and facies analysis result, it was found interval F which gave highest liquid rate of 2590 BPD has higher statistics of conductive features. Second highest production rate coming from interval C is also showing high amount of conductive image. Low production rate interval E shows lower statistics of conductive features. Image analysis shows interval C and interval F having resistive patches, dominant moldic porosity and nodular limestone. Low production rate intervals are characterized by facies of clean massive limestone with less secondary porosity. Facies analysis was exercised using electrical image log to characterize the reservoir. Identified image facies were mottled, bioclastic, vuggy, nodular, and clean to argillaceous limestone. Facies analysis based on conductive and resistive features from high-resolution electrical image has relationship with production rate from PLT. The study concludes that electrical image can be used to optimize completion design and hence to optimize production rate.