松北致密油水平井体积压裂技术适应性分析

Adaptability analysis of volume fracturing technology of horizontal wells for tight oil reservoirs in Songbei basin

松北致密油储层非均质性强、横向不连续,同区块不同井钻遇差异大,常规增产改造方法无法实现储量的有效动用,且无法直接评价压裂参数与产能的相关规律。通过引入评价参数“无因次动用比”,利用不同区块水平井压裂数据开展适应性分析,评价不同压裂参数对压后产能的影响。结果表明,I类储层分段产能贡献比远高于II类储层,可达60%以上;小的裂缝间距更有利于储量动用,且单缝改造规模与累计产量呈较好的正相关性;体积压裂模式中凝胶压裂液模式(切割模式)效果优于大量滑溜水前置液+凝胶携砂压裂液模式(复杂缝网模式)。

The tight oil reservoir in the north of Songliao basin is characterized by strong heterogeneity and horizontal discontinuity.Different wells in the same block have different drilling experience,so it is impossible to directly evaluate the correlation between fracturing parameters and productivity.Therefore,the depth adaptability analysis is carried out to evaluate the impact of different fracturing parameters on post fracturing productivity.The"dimensionless production ratio"is introduced to analyze the influence of different spacing on productivity.The results show that the contribution ratio of segmented productivity of type Ⅰ reservoir is much higher than that of type Ⅱ reservoir,up to more than 60%.Small fracture spacing is more conducive to reserve production,and there is a good positive correlation between single fracture reconstruction scale and cumulative production.In the volume fracturing mode,the gel mode(cutting mode)is superior to that of a large number of slippery water plus gel sand carrying mode(complex seam network mode).