陆相沉积油层水平井水平段轨迹对产能及采收率影响的研究

我国油田多属陆相沉积，油层内或多或少地存在着薄厚不等的夹层或隔层，而且分布不均。对于无气顶底水的这类油层，研究了有隔层水平井产能下降的幅度，研究了与油层相交贯穿油层上下的大斜度水平井和平行油层水平井的产能和采收率。计算分析结果表明：①存在夹层、隔层的油层不适合打平行油层的水平井；②对含有夹层、隔层的油层，选择与油层相交贯穿油层上下的大斜度水平井，可有效地降低夹层、隔层对产能和采收率的负面影响；③当相交油层的水平井长度为平行油层水平井长度的１．１５倍时，无论油层有无夹层、隔层，其产能要大于或等于相应平行油层水平井的产能，而且采收率不会受夹层、隔层的影响；④对无气顶底水的陆相沉积油层，选择与油层相交的长度略长的水平井是稳妥的。图３参６（陈志宏摘）

A study on the effect of reasonable trajectory of horizontal wells to production capacity and recovery factor in continental oil reservoirs.

Most oil fields in China are continental deposits. In a continental oil reservoir without gas cap and aquifer, interbeds commonly exist which are not uniformly distributed. For this reservoir, the s studied production lose of a horizontal well, and also made production and recovery comparisons between a high angle horizontal well that penetrates through the oil formation and a horizontal well with horizontal section parallel to the oil formation. For this type of reservoir, the calculation results show: It is not suitable to drill horizontal well with horizontal section parallel to the oil formation. The high angle horizontal well that penetrates through the oil formation is better, which can effectively reduce the negative effect of interbeds. When the penetrationetration section. And recovery factor will not be effected by interbeds. It is the best choice to drill high angle horizontal well with a longer pen length of the high angle horizontal well is 1.15 times greater than the length of horizontal section, whatever there are interbeds in the reservoir or not, its production capacity is higher than or equals to the production capacity of horizontal well with horizontal section parallels to oil formation.