有效厚度比率在储层评价中的应用——以苏里格气田X区盒8段为例

在碎屑岩有效储层的研究中,仅靠砂体厚度不能全面地评价储层,因此,在苏里格气田X区的研究实例中,使用了有效厚度比率这个参数。该参数反应的是有效厚度在砂体厚度中的比率。研究表明,盒8下段,尤其是盒8下2段有效厚度比率O值较少,是较好的储层,而盒8上段则有大量井点系数值为0,并证实了砂体厚度不能代表储层质量。工区的有效厚度比率与砂体钻遇率正相关,但与砂体厚度线性关系不明显。有效厚度比率受沉积与成岩等作用的共同影响,而在x区,成岩作用是导致比率变化的主要因素,而影响比率的其它地质因素,则有待进一步研究。

Application of effective thickness ratio in reservoir evaluation --Taking He-8 formation in X block of Sulige gas field as an example

Since it is unable to evaluate the reservoir comprehensively only by the sand body thickness in the study of effective reservoir of clastic rocks, the effective thickness ratio which means the ratio of effective sandstone thickness in the whole thickness of the sandstone is used in the studies of X block in Sulige gas field. The researches show that lower He-8 formation, especially the second lower part of He-8 formation, is an excellent reservoir with fewer wells with the ratio value of 0, while the upper layer has a large number of wells of that. It is also proved that the reservoir quality cannot be represented by the sandstone thickness. The effective thickness ratio of the work area is positively correlated with the drilling catching rate, but has unconspicuous linear relation with the sandstone thickness. The effective thickness ratio is influenced by activities such as the sedimentation and the diagenesis, while the diagenesis is the main factor causing ratio changes in X block. The other geological factors influencing the ratio need further studies.