The Mechanical Specific Energy (MSE) computed from commonly available drilling data such as torque, rate of penetration and weight on bit has been widely used to improve drilling efficiency. However, the more recent use of MSE for completion optimization has yielded conflicting results. FracGeo uses the Corrected Mechanical Specific Energy (CMSE) where the friction losses along the drill string and wellbore are accounted for and used to estimate, in real time, geomechanical logs, pore pressure, stresses and a natural fracture index. Various data ranging from seismic, to wireline, to microseismicity were used to validate the drilling derived logs. This technology represents a major step in completion optimization since it tackles the problem and provides the solution during the drilling phase. A major advantage of the new technology is its ability to be deployed on any rig without the use of additional surface gauges, sensors or downhole measurement tools, avoiding additional costs and potential risks of wellbore problems. Additional benefits of the technology include: no on-site personnel or permits, the use of existing real time drilling data streaming services to quickly steer in the most fracable rock, and having completion design immediately after drilling ends. This contrasts dramatically with alternative completion optimization methods for which data delivery, analysis, planning and design can take many days, if not weeks.
FracPredictor offers a customized software platform which provides an environment for engineers and geoscientists to model unconventional reservoirs. The new user friendly interface is organized to provide the professionals the tools they need to accomplish their daily tasks. The same software can aid experts and researchers in their deep investigations of various challenges facing their unconventional reservoirs. Within the same software multiple disciplines can find the necessary tools to facilitate their specific daily tasks. One software platform and one structured grid, means no external data export/import between disciplines and ensures preservation and seamless flow of information. The holistic approach powers workflows for sweet spot identification, landing zone selection, frac design, and reservoir modeling in unconventional and tight reservoirs which integrate all disciplines and their data to build a comprehensive Earth Model. Essential to the robustness of any model is the validation (not calibration as some others do) against a variety of data including but not limited to: blind wells, proxy logs from surface drilling data (using MSE after friction correction), microseismic, tracers, completion net pressure, and reservoir early time pressure during production. This results in a constrained approach where the previous models are used to reduce the uncertainty in the following disciplines models. The science driving the geomechanical simulations (continuum mechanics and the Material Point Method instead of Discrete Fracture Network models and Finite Element Analysis) incorporates the correct physics depending on the scale of the problem from far field to near wellbore, and incorporates models from the various disciplines (from geophysics, geomodeling, frac design, and reservoir modeling) within a single structured grid. Using this approach provides the option for real time model update to geosteer into the most fracable rock. This comprehensive, yet streamlined approach puts FracPredictor in a class of its own.
3G workflows provide a unique ability to build continuum models of natural fractures (using fracture proxy log calculation) through the application of Artificial Intelligence (AI ) technology which can integrate data from many sources to build the continuous fracture model (as well as all other petrophysical and geological properties). In addition to the natural fracture distribution, a key input to engineering are the rock mechanical properties of the reservoir which can be modeled at high resolution with our facies constrained stochastic pre-stack inversion or using log and/or surface drilling data when seismic is not available. These geologic models are translated into differential stress with our continuum mechanics based geomechanical simulator which allows one to capture the spatially varying initial differential stress conditions (these are sweetspots for fracing) based on simulating the interaction of regional stress with these causes of stress gradients within the reservoir at the pad or field scale. Our geomechanical simulation of fracing captures the interaction of the hydraulic fracs with these spatially varying natural fractures and elastic properties as well as incorporating stress shadow effects between stages and wells to capture the asymmetric half-lengths of the SRV which is used to constrain our frac design and then adapt the frac treatment to overcome these stress gradient at each stage. Our frac simulation method is meshless so no need to re-grid the model as the frac propagates and the simulator is particle based so no need to follow grid lines or impose empirical constraints on how the hydraulic and natural fractures interact as other products do.
The geologic and field depletion reality creates asymmetric hydraulic fractures that were not modeled in commonly used frac design software. The new workflow introduced by FracGeo uses geomechanical simulation to compute the stress gradients created by variable geomechanical properties, natural fractures and pressure depletion. FracGeo frac design workflow starts with geomechanical estimation of the stress gradients. These are translated into geomechanical half lengths that need to be honored in order to provide the correct fracture heights. When treatment data is available, it is added and honored as an additional constraint. For infill drilling or refracs, the simulation of depletion around a well is constrained by the geologic and asymmetric frac model so it is very quick to history match for 1 or 2 reservoir parameters instead of the typical 20 knobs reservoir engineers typically vary, this calculated pressure depletion feeds back into the geomechanical simulation together with the natural fractures and elastic properties of the reservoir to determine the initial stress conditions and the resulting strain due to hydraulic fracturing to constrain the frac design of the child well which is adapted to mitigate risk of frac hits between wells through the poro-elastic capabilities of our geomechanical simulation.