Degradable Particulate-Diverter Technology Diverts Acid in High-Water-Cut Reservoir

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 228528, “Application of an Innovative Degradable Particulate-Diverter Technology for Effective Acid Diversion in High-Water-Cut, High-Permeability-Contrast Reservoirs: A Case Study From Offshore Malaysia,” by Muhamad R. Bacho, SPE, Saurabh Anand, SPE, and Haydn B. Sinanan, SPE, Petronas, et al. The paper has not been peer-reviewed. _ This paper presents the application of degradable particulate-diverter technology to improve oil production by effectively diverting stimulation treatment fluids away from high-water-cut, high-permeability, high-temperature producing intervals or zones. This paper presents the application of degradable-particulate-diverter (DPD) technology, an engineered pill system consisting of proprietary degradable particles suspended in a viscoelastic carrier fluid, to improve oil production by effectively diverting stimulation-treatment fluids away from high-water-cut, high-permeability, high-temperature producing intervals or zones. The DPD technology was deployed to achieve temporary zonal isolation in high-water-cut intervals without the need for mechanical isolation tools or coiled tubing intervention. Case Study: Field A (Well 1 and Well 2) Candidate Selection and Analysis. The aim of the evaluation process was to identify well-demonstrated declining productivity combined with high water cut caused by preferential flow through high-permeability water-producing intervals from Zone I, where diversion could improve acid placement into oil-producing intervals significantly. The same high-permeability intervals of Zone I also could be found at the adjacent water injectors. Both Well 1 and Well 2 were producing at water cuts exceeding 80%, with a marked decline in oil rate despite sustained total liquid production. Production-logging tools (PLT) revealed that the lower sections of the completed intervals were contributing disproportionately high volumes of water. In Well 1, more than 90% of the total fluid production originated from a single high-permeability interval at the lower section of the reservoir. In Well 2, high-permeability streaks identified at the lower section of the reservoir were suspected to be dominated by water production. Openhole log data indicated significant heterogeneity within the targeted sandstone sequences. Permeability in the water-producing intervals was estimated to be an order of magnitude higher than in adjacent oil-producing intervals, creating an extreme mobility ratio during acid injection. Porosity distribution was relatively uniform, suggesting that the permeability contrast was primarily the result of differences in grain sorting, degree of consolidation, and presence of fines.