Geopressure is a critical property that must be understood to achieve success in your exploration and production efforts. SIGMA³ has assembled the finest team of pressure experts in the industry and offer superior solutions in geopressure that will enhance your exploration efforts and dramatically reduce your drilling and completion costs. Geopressure analysis is directly applicable to the following problems:
- Basin-Scale Modeling and Pressure Analysis
- Prospect-Scale Pressure Analysis
- Hydraulic Flow Analysis
- Hydrocarbon Migration and Maturation
- Lateral and Vertical Seal Analysis
- Pre-Drill Well Planning
- Wellbore Stability Analysis
- Real-Time Pressure Evaluation While Drilling
- Reservoir Specific Pressure Analysis (Centroid Analysis)
The analysis and prediction of pressure conditions in the subsurface ahead of the drill bit and while drilling is a critical aspect of the exploration process. Geopressure analysis uses geophysical data from seismic or logging sources to estimate the confining stress, pore pressure and other parameters that are critical to proper basin modeling, prospect analysis and well completion.
The workflow for accurate and robust geopressure analysis must include a high level of integration and expertise in seismic analysis, log analysis and well performance analysis. Our leading-edge geopressure experts provide robust solutions that can be easily integrated back into the interpreter workstation for use by the exploration team. SIGMA³ offers superior solutions in geopressure that will enhance your exploration efforts and dramatically reduce your drilling and completion costs.
- Basin-Scale Modeling & Prediction
- 3D Prospect-Scale Prediction
- Geopressure in Unloading Environments
- 3D Pre-Drill Prediction & Well Planning
- Post-Drill Analysis
Basin Scale Modeling & Prediction
Understanding the pressure regimes in sedimentary basins is a fundamental part of the exploration process. The pressure regime is a primary forcing agent in the maturation and migration of hydrocarbons, and their ultimate trapping in reservoirs that are reachable with the drill bit. SIGMA³ provides integrated geopressure analysis at the basin scale as part of our integrated interpretation services. Geopressure analysis at this scale usually uses 2D seismic data or 3D, if available, and any well information that is available for the basin. In cases where no well control is available, a qualitative assessment of the pressure regime using seismic velocities can still yield valuable insights into the hydraulic system of the basin, and can guide the explorationist to better judgment about the robustness of the petroleum system so that better economic assessments can be made for licensing rounds and regional exploration.
Prospect Scale Prediction
Understanding the hydrogeology and pressure regime of a prospect is critical to developing a clear picture of how fluids are migrating and being trapped in the prospect. Unfortunately, most prospects are developed without this critical information, which leads to a significantly larger number of dry holes in wildcat drilling. SIGMA³ uses prospect-scale pressure analysis as the next step in understanding the pressure regime of the basin as the exploration team refines its targets in preparation for drilling. Prospect scale pressure analysis is typically done on 3D data and uses dense velocity analysis and the REVEL™ process to obtain a detailed velocity structure that can be mapped into pressure using proprietary tools and expert knowledge. The result of such a pressure analysis is a detailed 3D pressure map of the subsurface that can be integrated with hydrogeologic flow modeling to determine the hydraulic behavior of the geological system, and better predict where hydrocarbons will migrate and be trapped, and whether regional and local seals will hold the hydrocarbon accumulations.
Geopressure Prediction in Unloading Environments
Pressure prediction is often performed in environments where multiple pressure mechanisms are active including unloading and secondary chemical compaction. In such environments, a more sophisticated methodology is required. SIGMA³ offers this methodology with our proprietary GEOPRESS™ 3D prediction tool. GEOPRESS has the capability to handle multi-mechanism calibration and apply these multiple calibrations using seismically mapped horizons to bound the top and base of each calibrated regime. The following examples show applications of this advanced method that allows the prediction process to honor robustly the correct physics for each pressure mechanism, which yields superior results compared to other approaches.
Pre-Drill Prediction of Reservoir Pressures
The prediction of pore pressure and fracture gradient ahead of the drill bit is one of the most critical tasks in planning a well. With deepwater well costs running upwards of $50 MM per well, this process should never be taken lightly as it can save the operator millions of dollars in avoiding a single well intervention or pressure event. SIGMA³ offers its pressure prediction services as part of the planning process, and our world-class experts work with your drilling engineers to help them understand the results of this process. With more than 100 years of experience in predicting pressures for well planning in a wide range of petroleum basins, SIGMA³ uses our depth of expertise and global experience to provide our clients with robust pressure solutions that save them significant amounts of money and pressure-related downtime on their wells.
Of particular concern in pre-drill planning is the role of reservoir pressures in well performance. The advent of the structural hyper-pressuring concept (also known as centroid theory) led us to develop an innovative and unique approach to the modeling of reservoirs during pressure prediction that allows for the prediction of reservoir pressures at the specific penetration point for a given well. The theory also allows for more accurate prediction of column heights pre-drill and assessment of seal failure risk.
An important part of the pressure prediction process is to analyze the results of each well as they are drilled. This analysis helps to improve the understanding of pressure regimes in and around petroleum prospects, and also improves the calibration process for pressure prediction related to future wells. SIGMA³ offers post-drill analysis as an extension of our pre-drill pressure prediction process. The post-drill analysis allows the client to learn more about the pressure regime of their prospects, and can also help the geoscience team better assess the economic viability of prospects that may be marginal in size after the first exploration wells are drilled. It also closes the loop on the pre-drill process and allows an assessment of the true error bars on the pressure prediction in areas where little to no calibration information existed before the well was drilled. Clients can integrate the learnings from previous wells with the planning for future wells so that difficult drilling zones, unusual formation properties and other adverse drilling conditions can be properly evaluated and understood in future wells to mitigate the risk of problems related to those conditions.
- Offshore Global Webcast: Geohazard Prediction in Deepwater Wells – When the Reservoir is the Enemy
- American Oil and Gas Reporter, September 2011: Pore Pressure Prediction In Complex Geologic Environments – Stratabound Pressures In The Woodbine Formation
- Pore Pressure/Fracture Prediction in the Texas Woodbine Trend
- CSEG Recorder, April 2006: Velocity Determination for Pore Pressure Prediction
- Hart's E&P Deepwater, July 2003: Shallow-Water Trouble in Deep Water: New Techniques for Predicting and Dealing with Shallow Water Flows
- The Leading Edge, September 2001: The Petrophysical Basis for Shallow-Water Flow Prediction Using Multicomponent Seismic Data
- Subsurface Geohazards Brochure
- Recent Advances in Pore Pressure Prediction in Complex Geologic Environments
MEOS, 2011/SPE 142211-PP
- Pore Pressure Prediction based on High Resolution Velocity inversion in Carbonate Rocks, Offshore Sirte Basin - Libya
- The Vp/Vs Inversion Procedure: A Methodology for Shallow Water Flow (SWF) Prediction from Seismic Analysis of Multicomponent Data
- The Future of Pressure Prediction Using Geophysical Methods
AAPG Memoir 76, 2002
- Pore Pressure Estimation From Velocity Data: Accounting for Overpressure Mechanisms Besides Undercompaction
IADC/SPE Drilling Conference, 1994