基于正交试验的低渗透油藏裂缝参数优化研究

Research on Optimization of Fracture Parameters of Low Permeability Reservoir Based on the Orthogonal Test

水平井压裂技术作为提高低渗透油气藏产量的一项重要技术已在各大油气田实现了高效产能。但在压裂过程中,各裂缝参数会对裂缝产能产生影响。对单一因素的考量只能实现在单方面的参数优化,无法获得最优的压裂方案。正交试验方法能够实现对多因素的综合考量,运用正交及数理统计方法可以设计出一定数量的正交试验方案,通过极差分析方法可以得到各因素的最优水平及对最终结果影响程度最大的因素。选取裂缝长度、裂缝条数、裂缝导流能力及裂缝方位角四个裂缝参数,每个参数设置四个参数水平,通过正交试验可以获得最优试验方案为:裂缝方位角75°、裂缝导流能力50μm^2·cm、裂缝条数4条、裂缝长度150 m。该试验方案在X油田M区块得到了明显的增产效果。

As an important technology to increase the production of low permeability reservoirs, the horizontal well fracturing technology has realized high efficient production capacity in many oil and gas fields. But in the process of fracturing, the fracture parameters can affect crack capacity. The consideration of single factor can only realize optimization of unilateral parameter, which can not get the optimal fracturing scheme. Orthogonal test method can realize the multifactor comprehensive consideration of various factors, a certain number of orthogonal test plan can be designed with the orthogonal and mathematical statistics method. The optimal level of various factors and the factor which has the biggest influence on final results can be achieved through the range analysis method. The four fracture parameters including length, number, diverting capacity, azimuth were chosen, and four parameter levels were set for each parameter. The optimal experiment scheme was achieved through orthogonal test： the azimuth 75°, the diverting capacity 50 μm2·cm, the number 4 and the length 150 m. The test plan has achieved obvious stimulation effect in M block of X oilfield.