同轴式双空心抽油杆下入深度设计方法

同轴式双空心抽油杆加热系统可有效解决高凝油井井筒易结蜡、稠油井产液黏度较高的问题,但考虑油井生产效率、开采成本及综合的经济效益,需要计算出最佳的抽油杆下入深度。以井口出油温度最优为目标,同轴式双空心抽油杆下入深度、循环水进口温度为约束条件,建立了井口出油温度C计算模型。利用该模型进行求解时,先用迭代法进行同轴式双空心抽油杆下入深度优化,然后在优化结果基础上进行抽油机载荷校核。建立的井口出油温度计算模型及同轴式双空心抽油杆下入深度确定方法,在现场13口油井进行了应用。结果表明,该方法避免了以前设计人员凭经验确定抽油杆下深的弊端,可靠性更高,且有效时率平均提高14.1百分点,既满足了生产需要又节省了油井开发成本。 

Determination Method for the Landing Depth of Coaxial Dual Hollow Rod

Coaxial hollow rod heating system is effective in solving the problem of wax deposition in borehole for high pour point oil well and high viscosity for heavy oil well.However,considering oil well production efficiency,cost and comprehensive economic benefit,it’s necessary to calculate the optimal landing depth of the sucker rod.Aiming at wellhead oil temperature optimum and taking sucker rod depth and circulating water inlet temperature as constraints,the wellhead oil temperature C(x,t)relation model was established.In the model,it first uses iterative method to optimize the landing depth of coaxial hollow rod and then checks the pumping load based on the optimization results.This model has been used in 13 oil wells instead of sucker rod depth estimation from experience.The effective rate increased by 14.1 percentage which meets the production needs and saves the cost of well development.