Analysis of Seismic Damage Zones: A Case Study of the Ordovician Formation in the Shunbei 5 Fault Zone, Tarim Basin, China

Zhan Zhao,Wenlong Ding,Ruiqiang Yang,Gang Zhao,Jingtao Liu

doi:10.3390/jmse9060630

Abstract

Fault damage zone has an important influence on subsurface fluid flow and petrophysical properties. Therefore, it is of great significance to study the characteristics of fault damage zone for oil and gas development of ultra-deep carbonate formation. This study uses seismic data and the derived variance attribute to identify two types of damage zones and analyze the spatial geometric characteristics of the damage zones. The results show that the type 1 damage zone is wider than the type 2 damage zone. The width of damage zones distributed on both sides of the Shunbei 5 fault core shows obvious asymmetry, and the damage zone width and throw conforms to the typical power-law distribution on the log-log plot. We discuss the factors affecting the width of the damage zone and its formation process. Finally, we discuss the influence of the damage zones on oil and gas exploration. It seems that the seismic variance attribute is a useful technique for characterizing the ultra-deep strike-slip fault damage zones.

Highlights

A large number of field observations have shown that the fault zone is mainly composed of a narrow fault core and wide damage zone (Figure 1) [1,2]
The fault core is usually composed of fault gouge and breccias
Because oil and gas are mainly distributed we mainly focus on the characteristics of the Ordovician fault damage zone

Summary

Introduction

A large number of field observations have shown that the fault zone is mainly composed of a narrow fault core and wide damage zone (Figure 1) [1,2]. The fault core is the place where the displacement of the fault is concentrated, and the stratigraphy has experienced strong structural deformation. The fault core is usually composed of fault gouge and breccias. The damage zone is immediately adjacent to the fault core and usually develops multiple groups of fractures and secondary faults [3,4]. The damage zone is the product of the formation rheology and displacement on faults. Due to the complex fracture network within damage zones, the geometry size and architecture of damage zones have a significant effect on the migrations, and accumulation of subsurface fluids [5,6]

Methods

Discussion

Conclusion