3D accurate description of igneous rocks in southern Bohai: A case study in BZ-X oilfield

Abstract

BZ-X oildield is located into the southern of Bohai Bay Basin. The igneous faces of BZ-X oilfield include volcanic conduit facies, overflow facies, eruption facies and intrusive facies. Igneous rock occupy reservoir space and influence the reserves calculation and well location decision, accurate description of igneous rock becomes an important part of the oil field reserves evaluation and oilfield development. In this paper, the new approach is put forward to make accurate description of igneous rock, which is integrated with forward modelling, geobody interpretation and multi-Z interpretation. By seismic forward modelling, the seismic response characteristics of different volcanic rock facies were analysed. By applying different seismic attributes, a geological feature can be better delineated and extracted as a geobody, we realize three-dimensional carving of overflow facies and intrusive facies by geobody interpretation. By multi-Z interpretation method, the body of volcanic conduit and eruption facies was curved accurately by 3D multi-Z interpretation based on the seismic response. Our method provides a new research thought about accurate description of igneous rock. It generates a more reliable geologic body and help to better adjust well position. The result of well drilling shows that our proposed approach is effective and applicable. Note: This paper was accepted into the Technical Program but was not presented at IMAGE 2021 in Denver, Colorado.