Fracture detection by using full azimuth P wave attributes

Abstract

A type of specific fractured hydrocarbon reservoir, a shale fractured reservoir, exists in the Shengli oilfield. Due to very small porosity of this type, low sensitivity to the variation of petrochemical property parameters, and strong anisotropy, it is very difficult to explore for them. So far, there is no set of mature methods for recognition of direction, distribution, and density of the fractures by an integrated analysis of geologic, geophysical, well log, drilling data, and etc. This paper presents a new method for acoustic impedance variation with azimuth (IPVA), based on existing fracture detection methods. Seismic acquisition, processing, and recognition techniques were developed for detecting directional vertical fractures using multi-azimuth P wave data in combination with the seismic and geological features of shale fractures in the Luojia area. The IPVA research is carried out for recognizing the distribution, strike, and density of fractures based on the study of velocity variation with azimuth (VVA) and amplitude variation with azimuth (AVA) for full azimuth P wave data at different CMP positions. Through practical application in the Luojia area, primary results have been obtained which verifies that the IPVA method provides good potential for quantitative detection of parallel, high angle, shale fractures.

Fracture Characterisation Using 3-D Seismic Reflection Data for Advanced Deep Geothermal Exploration in the Ne German Basin

“…Approaches considering Amplitude Variation with Offset or Azimuth (AVO, AVA respectively) as well as Velocity Variation with Azimuth (VVA) have widely been implemented for hydrocarbon exploration (e. g., Lynn et al, 1999;Hall and Kendall, 2003;Al-Marzoug et al, 2006;Lüschen et al, 2014;Aleardi et al, 2015;Schmelzbach et al, 2016), especially to identify fracture-induced anisotropy (Garotta, 1989;Alkhalifah et al, 1995;Craft et al, 1997;Li et al, 1999;Bakulin et al, 2000;Jenner et al, 2001;Shen et al, 2002;Shouli et al, 2007;Wang et al, 2007;Gray, 2007;Liu et al, 2014).…”