OpenPetro Suite Overview

OPS is an integrated geophysics and geology research software system which was developed by PST. The basic infrastructure and data management functions of this system are of great perfection. Up to now, the completed applications, which based on this system, include seismic attribute computation, fault imaging, reservoir fracture analysis, seismic spectral decomposition, random seismic inversion, etc.

Based on creative algorithms developed by PST’s talented geophysicists, the seismic geometric attributes in OPS are of high resolution. MPD spectral decomposition with high resolution can reflect more details of the reservoir distribution (especially thin reservoir).

For OPS we will develop more specialized packages, which include the seismic interpretation,seismic inversion, and geologic modeling.

Advanced Geometric Attributes

Usually the seismic curvature is acquired by scanning in an ellipsoik, which is low accuracy. In FracPM, restrained by angles, azimuths, scanning curved surfaces, we calculate geometry attributes by global optimization. The advanced geometric attributes are used to imaging faults or cracks of high resolution.

        The evolution of seismic geometric attributes

Scanning in ellipsoids;                        in curved surfaces

        Seismic stack section vs. its geometric attributes

        A geometric attribute time slice

        Geometric attribute time slice

Seismic Spectrum Decomposition

Seismic spectral decomposition includes short time Fourier transform, CWT wavelet transform, S transform, S transform and wavelet decomposition of MPD. Among them, the decomposition based on MPD has the highest resolution.

        Four algorithms of spectral decomposition

        30Hz of MPD decomposition

Fracture Research

Step 1 Seismic Curvature Calculation

Big-scale fractures, or faults can be identified directly by seismic geometric attributes. However, Small-scale fractures which contribute to the permeability of the reservoir can only be identified through the data from boreholes, such as FMI.

Step 2 Fracture Analysis

The fractures derived from FMI data can be grouped according to their azimuths and inclinations. Then the line densities, area densities and volume densities for each group will be computed.

Step 3 Fracture Density Prediction

The correlation analysis between borehole fracture density and seismic geometric attributes is made. Some sensitive attributes are selected to be constraining conditions. Then fracture density volume can be computed by extrapolation from well fracture density curve.

Step 4 Fracture Permeability Prediction

After acquiring the fracture density volume, with the fracture conductivity derived from well test data, OPS will be able to compute the fracture permeability.