伊朗Y油田深井油套环空封隔液评价与优化研究

Evaluation and Optimization Study on Deep Well Completion Tubing Casing Annulus Packer Fluid in Y Oilfield of Iran

摘要:

伊朗Y油田主力产层F油层属于典型的高温、高压、高产、有腐蚀性流体产出的油田。为了保障该油田的长效、高效、安全生产，需要对完井工艺及管柱保护进行防腐研究。采取完井时下入带封隔器的完井管柱，并在封隔器之上的油套环空注入防腐封隔液；室内对引进的2种环空封隔液体系进行了互溶性、高温稳定性、杀菌性等基础理化性能及对井下管材的腐蚀性的实验及评价。评价结果表明,CaCl2型环空封隔液高温稳定性较差，浸泡腐蚀速率值高值为0.062 mm/a，电偶腐蚀速率值高值为0.078 mm/a，均大于设定的腐蚀速率值0.05 mm/a。而引进的NaCl KCl型环空封隔液高温稳定性较好，浸泡腐蚀速率值高值为0.014 mm/a，电偶腐蚀速率值高值为0.037 mm/a，均低于设定的腐蚀速率值0.05 mm/a。鉴于此情况，对引进的CaCl2型环空封隔液进行改进并优化设计，确定合适的CaCl2型环空封隔液体系。优化设计后的CaCl2型环空封隔液高温稳定性良好，浸泡腐蚀和电偶腐蚀速率值均低于设定的腐蚀速率值，综合性能达到了现场应用要求。

Abstract:

Freservoir in Y Oilfield is characterized with high temperature, high pressure and high yield with corrosive fluids. In order to ensure a long term, efficient and safe production, it is necessary to study the well completion technology and anticorrosion for string protection. The completion string with packer is run downhole, and the annulus between tubing and casing above packer is then filled with anticorrosion packer fluid. Two introduced annulus packer fluid systems are tested at lab to evaluate the physical and chemical properties of , high temperature stability, and the corrosion of pipe downhole. Test results show that CaCl2 annulus packer fluid has poor high temperature stability, the high values of immersion corrosion rate values and galvanic corrosion rate values are 0.062 mm/a and 0.078 mm/a respectively, larger than the set corrosion rate of 0.05 mm/a. While the introduced NaCl KCl annulus packer fluid has better high temperature stability with high values of immersion corrosion rate values and galvanic corrosion rate values 0.014 mm/a and 0.037 mm/a respectively, lower than the set corrosion rate of 0.05 mm/a. In view of this situation, the improvement and optimizing design are made on this introduced CaCl2 annulus packer fluid to determine the proper system. The optimizing designed CaCl2 annulus packer fluid shows good high temperature stability, the immersion corrosion and galvanic corrosion rate values are below the set corrosion rate, and the overall performance have reached the field application requirements.