CO_2吞吐法在低渗透油藏的试验

CO 2 stimulation test in low permeability reservoir

针对江苏油田低渗透复杂小断块油田，其油藏分散、储量少，形不成常规注采对应井网的特点，进行ＣＯ２吞吐，在保证气源的条件下，可与压裂增产法相媲美。通过ＣＯ２对江苏油田典型原油的作用研究，分析了ＣＯ２与原油的最小混相压力；提出了在长岩心物理模型上进行的吞吐试验，明确了ＣＯ２吞吐的主要机理。同时给出了用组分模型进行吞吐数值模拟研究的结果，确定了各影响因素的敏感性。结果表明，在具有丰富ＣＯ２资源的江苏油田，进行ＣＯ２单井吞吐来提高原油采收率是可行的。

Oil fields in Jiangsu have the features of low permeability, complicating, small fault blocks, dispered and little reserves, and coventional injection production pattern can not be formed in the oil fields. According to these, CO 2 stimulation,if with sufficient gas guarantee, would be as effective as fracturing. Through study of the effect of CO 2 on typical crude in Jiangsu, this paper analyses the minimum miscible pressure between CO 2 and crude oil, demonstrats that to carry out stimulation test with long core physical model, and definites the main mechanism of CO 2 stimulation. This paper also provides the result of stimulation numerical modelling carried out by compositional model, and determined the sensitivity of each influence factor. The result shows that oil fields in Jiangsu, which has plentiful CO 2 resources, it is feasible to enhance recovery factor by CO 2 stimulation in single well.