深层稠油减氧空气吞吐注气量确定方法研究

A Study on Optimized Method of Gas Injection Volume of the Oxygen-reduced Air Flooding in Deep Heavy Oil Reservior

鲁克沁油田减氧空气吞吐注气时一般采用笼统注气,没有相关优化注气量的明确方法,导致增油效果在不同类型单井之间有较大差异。为此,通过物模实验确定优势通道注气量,进行数值模拟并提出优势通道注气系数α、优势通道进气系数β的概念,结合优势通道体积优化注气量。通过模拟不同注气量吞吐时的换油率大小来验证优化结果是否正确,得到对实际现场应用的注气量有理论指导作用的优化计算公式。实验表明,最优注气量为0.20 PV,优势通道注气系数为0.8,表明有80%的气进入到优势通道中,优势通道进气系数为0.348,说明距生产井约1/3的井距范围为受效区域。经过注气量优化公式计算和数模验证,最优注气量为4.5×10^(5) m^(3)是合适充分的。优化方法结合减氧空气吞吐的增油机理与现场实际需求,对减氧空气吞吐注气量的相关设计具有一定的理论意义和现场应用价值。

Lukeqin Oilfield adopts general gas injection in oxygen-reduced air flooding.There is no established method for optimizing gas inj ection,which results in great differences in oil production increase effects between different types of single wells.The pore volume multiples of gas injection in the dominant channel are determined through physical model experiments;numerical simulation experiments are carried out to propose the concepts of the gas injection/inlet coefficientαandβin the dominant channel,which are combined with the volume of the dominant channel to optimize the throughput.By simulating the oil exchange rate during the throughput of different gas injection volumes to verify the optimization results,an optimization calculation formula with theoretical guidance for the actual gas injection volume in the field is obtained.The experiments show that the optimal gas injection pore volume multiple is 0.20 PV,and the gas injection coefficient a of the dominant channel is 0.8,indicating that 80%of the gas enters the dominant channel,and the gas inlet coefficient of the dominant channel is 0.348,indicating that 1/3 of the well spacing to the production well is the distance the affected area covers.After the calculation of the gas injection volume optimization formula and the verification of the digital model,we conclude that the optimal gas injection volume of 4.5×10^(5) m^(3) is adequate.The optimization method combines the oil increasing mechanism of oxygen-reduced air throughput with the actual demand in the field,and has certain theoretical significance and field application value for the related design of oxygen-reduced oxygen throughput.