نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشگاه صنعتی امیرکبیر (پلی تکنیک تهران)، دانشکده مهندسی نفت
2 دانشگاه صنعتی امیرکبیر
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Well completion fluids are crucial for the successful completion and workover of oil and gas wells, particularly in challenging reservoirs characterized by high temperatures, high pressures, and low permeability. The primary objective of this study is to investigate and evaluate the formation damage inflicted by two novel packer fluids: one phosphate-based and the other nitrate-based. In this research, two high-density completion fluids have been used. The first fluid is the phosphate based fluid with a density of 114 pcf and the next fluid is the nitrate based fluid, which has reached a density greater than 95 pcf by the addition of solvents. This research has conducted various formation damage tests, including assessments of wettability alteration, clay swelling, compatibility of the packer fluid with reservoir fluids, and fluid invasion into the plug (coreflood). The experimental results reveal that compatibility assessments of the fluids indicate no emulsion formation with crude oil and condensates for all fluids tested. However, in the evaluation of formation water compatibility with the phosphate-based fluid, a minor amount of precipitation was observed. Fluid invasion tests into carbonate and sandstone plugs for the phosphate-based fluid demonstrate that this fluid can cause 41.17% and 30.5% reduction in formation permeability, respectively. In contrast, fluid invasion tests into carbonate plugs for the nitrate-based fluid show that this fluid can cause 29.33% reduction in formation permeability, which is significantly less than that caused by other fluids such as drilling mud. Furthermore, the results from the clay swelling tests indicate that the clay swelling caused by both fluids is less than 5 milliliters per 2 grams of clay. Consequently, these fluids can be employed as packer fluids in oil and gas wells, enhancing efficiency and safety, particularly in challenging reservoirs with high temperatures, high pressures, and low permeability.
کلیدواژهها [English]
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