Tag Query Results
1 Carbonate Reservoir Evaluation Workflow and Decision Matrix
Published: 31 Mar 2019, 5:28 p.m. Revised: 10 Apr 2019, 7:20 a.m.These pages provide a workflow for the systematic interpretation and evaluation of carbonate platforms. This is provided in the form of a decision matrix that can be used to:
- establish the presence, or not, of a carbonate platform
- appraise reservoir presence and the development potential of a discovered carbonate platform
- recommend cost-effective and scientifically robust methods to improve recovery from producing carbonate fields
The decision matrix should be used as a guideline by which carbonate platform presence, structure, stratal architecture and diagenetic overprint can be assessed. It is not intended that a full range of reservoir properties will be provided, but guidance will be given on the most appropriate reservoir analogues.
A summary of the workflow is provided here workflow.pdf
2 1 Frontier and Basin Exploration
Published: 31 Mar 2019, 5:30 p.m. Revised: 2 Jun 2023, 5:15 p.m.During basin-scale/frontier exploration, there is often uncertainty as to the presence, or not, of a carbonate platform or other carbonate strata in the subsurface. Often, poor quality seismic and an absence of local knowledge hinders confident identification and characterisation of carbonate strata. In the worst cases, structures are drilled and discovered to not be carbonate platforms, or indeed any form of potential reservoir (Burgess et al., 2013). It is possible to either fail to identify carbonate platforms, due to poor seismic data quality, or to incorrectly interpret positive structural features, eroded topographic features or palaeo-volcanic structures as carbonate platforms.
The focus of this workflow is on a) assessing the likelihood of carbonate presence and b) correctly mapping the size, distribution and geometry of the carbonate platform.
3 Stage 1 Structural Evaluation
Published: 21 Mar 2019, 2:32 p.m. Revised: 2 Apr 2019, 8:07 p.m.The rationale behind the workflow for this phase of reservoir evaluation is to refine estimates of in-place volumes and determine the reservoir recovery factor based on a range of potential recovery mechanisms. The workflow largely follows that defined for basin scale/frontier exploration, but assumes-
a) Prior analysis of basin formation mechanism, tectonostratigraphy and palaeo-plate reconstruction
b) A richer dataset, for example reprocessed seismic data, well data and/or more evolved analogue studies
c) A larger, more multi-disciplinary team, including petrophysicists, reservoir engineers and well & production engineers
4 Stage 2 Seismic interpretation of carbonate platforms
Published: 2 Apr 2019, 8 p.m. Revised: 2 Apr 2019, 8 p.m.This workflow resembles that used for frontier exploration, but assumes that the presence of a carbonate platform has been confirmed, data quality is higher and more well data is available for calibration. It also assumes that fault mapping has been refined.
5 Stage 3 Sedimentological and diagenetic interpretation of well data
Published: 2 Apr 2019, 8:05 p.m. Revised: 2 Apr 2019, 8:05 p.m.If core is available during appraisal, then it should be optimised for geological interpretation. It is expected that this will be conducted partly in parallel with core petrophysical analysis, although there is value in ensuring the routine core petrophysical data is used to select samples for petrographical anlaysis.