Estimation of Reserves
Reliable estimation of hydrocarbon reserves-in-place with accuracy matching present international standards is impossible without preparation of detailed 3D geological field models that essentially must:
- Integrate all available geoscience and production data on the field.
- Use the knowledge base realized in a software system as modules and algorithms unique for the field.
- Be able to incorporate professional geological knowledge of the software system user.
The above principles are successfully implemented at CGE by deploying CGE-developed software systems DV-Geo and DV-SeisGeo as tools always enabling reliable and trustworthy estimation of HC reserves (DV-Geo is officially recommended by the GKZ State Commission on Reserves for use in estimating hydrocarbon reserves).
These two systems realize an effective technology with the following capabilities:
- creation of a geoscience and production data base with intuitive access to objects of concern in the knowledge domain
- dynamic display of initial and interpreted data as side-by-side images
- possibility of flexible planning of geological modeling operations by the user
- effective parameter selection for mapping algorithms regardless of the amounts and diversity of geoscience data involved and variety of problems addressed, thus permitting geologically plausible and high quality results
- use of effective algorithms and programs for 3D modeling enabling the user to achieve maximum match of the 3D model with geologist’s assumptions and initial data
- use of special unique algorithms permitting full consistency to be attained between 3D models and layer maps showing hydrocarbon reserves and detailed geological structure, which would provide sufficient grounds for experts at the GKZ State Commission on Reserves to approve the presented estimates
Technological chain involving the use of the DV family of software program packages is as follows:
- Creation of data base for and generalization of initial geoscience and production data including the results of regional geological surveys that provide knowledge about stratigraphy, tectonics, paleo-geomorphology, paleo-geography, lithology and facial characteristics of sedimentation in the region.
- Analysis and generalization of 2D/3D seismic data. Generation of a field structural-tectonic model.
- Preparation of petrophysical model, processing and interpretation of well logging data:
- review of core analysis data, analysis of lithological-petrographical, petrophysical and transmissibility-storage properties of reservoirs derived from cores and preparation of "core - core" crossplots
- obtaining relationships such as "core - log", "log - log " and "well-tests - logs", and validation of well logging data interpretation methodology
- processing and interpretation of well logging data, definition of main parameters of (terrigenous and carbonate) reservoirs
- Analysis of hydrodynamic investigations in wells.
- Generation of digital geological model:
- correlation of productive deposits and identification of facies zones
- preparation of basic model of the field
- location of fluid contact positions
- identification of reserves estimation prospects
- generation of digital 3D/2D geological models of productive beds
- Estimation of HC reserves-in-place:
- validation of physical-chemical properties of reservoir fluids
- validation of HC reserves estimation parameters and estimation of reserves-in-place (by layers, by identified zones and categories) according to the Russian classifications and classifications of SPE/WPC/AAPG
- comparison of the HC reserve figures, thus obtained, with those available at the RGF Russian Geological Archival Data Office
- estimation of associated product reserves
During 2002-2007, CGE completed 16 projects for estimation and express-reestimation of hydrocarbon reserves-in-place and recoverable reserves. The projects were submitted to and accepted with approval at the RF central and regional Commissions on Reserves.