mshoemaker@scicatoil.com | 713-515-1155 | Houston
SciCat Geo (or SciCat®) is a subsidiary of SciCat Oil LLC founded in 2011, and is a subsurface technology advisory company
mshoemaker@scicatoil.com | 713-515-1155 | Houston
SciCat Geo (or SciCat®) is a subsidiary of SciCat Oil LLC founded in 2011, and is a subsurface technology advisory company
SciCat® has developed proprietary and award winning seismic geomechanics technology that measures in-situ 3D minimum horizontal stress which is the key rock parameter that governs hydraulic fracture stimulation of tight geologic formations, not only for enhanced energy production, but for controlled fracture design and minimal footprint.
The novel technology and method is the recent recipient of the 2020 prestigious AAPG Levorsen Memorial Award for innovation in subsurface exploration.
Changes in rock geomechanics and subsequent minimum stress define stimulated rock volume (SRV) and reservoir extent, which drives well performance and ultimate recovery of hydrocarbons and geothermal liquids, for enhanced brown and green energy production.
Intrinsic stress heterogeneity can now be measured in 3D space at the well pad, ahead of the drill bit. The cutting-edge technology provides subsurface geomechanics and stress variability necessary to maximize hydraulic fractures near wellbore and far-field in 3D space.
SciCat's stress solution allows for optimal landing and horizontal wellbore trajectory design, engineered completions design, and subsequent wellbore spacing for production optimization, and reduced drilling and completion cost for capital efficiency.
SciCat's stress solution stems from a unique seismic-to-simulation multidisciplinary approach, integrating high resolution calibrated mechanical earth models with 3D seismic geomechanics measured in-situ from AVO seismic inversion. The resulting minimum stress can be input directly into 3D fracture geometry simulators like GOHFER® .
The technology has been successfully applied to the prolific Midland and Delaware sub-basins of the greater Permian Basin, the results of which have been peer-reviewed and published.
SciCat's core objective is to provide E&P operators the competitive technical advantage necessary to optimize production and minimize drilling and completion costs for capital efficiency. SciCat uses proprietary technology in maximizing fracture stimulation for efficient drilling and completions, and for optimal field development ahead of the drill bit.
SciCat's innovation implements a unique multidisciplinary/multiphysics approach, integrating high resolution 3D mechanical earth models with seismic geomechanics for Earth stress state variability, coupled with broad technical assurance and decades of direct E&P operations experience within unconventional and conventional plays worldwide.
SciCat remains very conscious of carbon emissions, climate, and cultural values and continues to address and execute effective environmental, social, and governance (ESG) criteria using modern technology to mitigate and decelerate said environmental effects, while minimizing the carbon and environmental footprint of E&P companies including hydrocarbon and geothermal energy operators, and for optimal and safe CO2 storage.
Geological parameters that must be taken into consideration before the implementation of CO2 storage methods include porosity-permeability and the thickness and depth of the reservoir formation which speaks to the in-situ stress state of the Earth, in addition to cap rock integrity and sealing properties of faults (Koukouzas et al., 2020).
Additional factors that substantially affect the implementation of geological storage methods involve environmental issues (CO2 leakage) which speaks to the mechanical stress state of the Earth.
Like the conventional petroleum system, a Carbon Storage System (CSS) has essential subsurface elements with uncertainty and risk assigned to each element that must be investigated and defined, in this case for safe and efficient containment prior to application which speaks to integrity of the rock and minimal horizontal stress.
Emerging methods involve not only the artificial creation of storage space and confinement in tight rocks, but safe containment which requires measurement of rock properties and in-situ stress states of the Earth involving geomechanical stratigraphy and the Mechanical Earth Model (or MEM).
Such methods represent a similar approach with application of in-situ stress states and the MEM relative to the development of unconventional oil and gas resources and fracture stimulation of tight rocks, in this case for environmentally safe containment of CO2 with knowledge of geomechanics and subsequent fracture geometry in defining the CSS.
When hydraulic induced injection pressures exceed in-situ minimum stress, fractures occur and will propagate orthogonally and perpendicularly away from the wellbore far-field within a path of least resistance determined by stress heterogeneity, defined by lithology (or mineralogy) contrasts of the subsurface. Lithology contrasts define intrinsic 3D seismic geomechanics or elastic properties of the shale that are effectively measured by the AVO seismic inversion in 3D space.
The measured stress from SciCat® is versatile, allowing for data-driven solutions, contrary to trial-and-error development methods that are capital intensive. Applications include optimal landing and horizontal wellbore trajectory design, geosteering, identifying drilling hazards, 1D and 3D fracture geometry modeling for vertical and lateral wellbore spacing, pre-drill engineered treatment design for enhanced production and less cost (including vertical wellbores), effective zipper sequencing for stress shadow mitigation, refrac assessment, and wellbore stability applications.
Far-field stress variability from SciCat® is driven by in-situ 3D seismic geomechanics defined by lithofacies and mechanical stratigraphy of the rocks which ultimately governs fracture geometry including height and length.
For example, stacked horizontal wellbores landed in the Lower Spraberry formation, seen here from the Permian Basin, are typically separated vertically by just 200 ft. with stress differentials greater than 1,200 psi (red to purple). The black curves define individual vertical stress profiles extracted from the same section which are vertically sampled at 1 ft.
The upper landing is characteristic of higher stress rocks due to the addition of clay and organics by volume warranting a tighter spacing of 200 ft. totaling 22 stages. The lower "landing2" zone is characteristic of lower stress (more brittle) due to proportionally less clay and more carbonates, thus warranting a relatively wider spacing of 250 ft. totaling just 17 stages.
With less frac stages, the lower landing completion costs are reduced by ~$350,000 per well, a significant savings for a 12-well pad and without compromising production. Optimal stage spacing from stress heterogeneity can be confirmed using fracture modeling as seen below.
Seismic-stress cubes are corrected for anisotropy using core integrated with mechanical earth models, and can be input directly into fracture geometry simulators like GOHFER® with the necessary stress variability at the area of interest, contrary to current methods that interpolate geomechanics from vertical wells.
E&P’s operating tight oil and gas plays continue to implement development strategies that involve cookie-cutter completion designs that use identical geometric stage / cluster spacing. Such development strategies fail to account for changes in geology, specifically minimum stress heterogeneity near wellbore and far-field which governs stimulated fracture complexity. The measured stress can be input directly into 3D fracture geometry simulators like GOHFER® .
The same Lower Spraberry example from the Permian shows stacked horizontal wellbores with stress heterogeneity measured in-situ by seismic geomechanics (bottom section), contrary to interpolated stress from vertical logs without seismic which fails to account for the vertical stress differential separating the stacked wellbores (middle section). Without accounting for stress heterogeneity, modeled fracture lengths appear equal and the stacked wellbores would have otherwise been completed identically at significantly increased cost.
Near wellbore minimum horizontal stress from SciCat® can be input directly into completion modeling software in 1D and 3D space for optimal stage and cluster spacing determined by stress differentials for enhanced treatment sensitivity analysis that is data driven, resulting in optimized fracture stimulation with mitigation of stage-to-stage and interwell frac hits. Example here is from CORDAX ® using stress input from SciCat.
Changes in geology define intrinsic 3D seismic geomechanics or elastic properties of tight rock that are effectively measured by the seismic directly at the area of interest. SciCat integrates the seismic with mechanical earth models defining near wellbore and far field vertical and horizontal stress variability for interwell frac hit mitigation in 1D and 3D space.
Until now, quantitative minimum stress has been next to impossible to measure far-field, particularly in 3D space. Other industry methods used to infer stress are uncertain and non-unique based on drilling data and frac hit pressure response, or indirect modeling methods that extrapolate / interpolate rock geomechanics to the well pad from significant distance.
Said methods are valuable for corroboration, but data is limited qualitatively to the wellbore only. SciCat however measures stress directly and quantitatively at the well pad, between wells in 3D space, using calibrated mechanical earth models integrated with geomechanics measured in-situ from the inverted seismic moduli.
Assets can now be characterized based on reservoir and completion quality fairways and evaluated basin-wide for longer term development strategies that are less conducive to parent-child and frac hit phenomena, resulting in improved capital efficiency.
Moreover, subsurface data required to measure the stress includes 3D seismic and modern logs, representing data most operators likely have, adding value and further reducing costs.
Lateral and vertical drilling markers for structural in-zone trajectory design and drilling can now be defined based on mineralogy contrasts that define the geomechanics and stress measured by the inverted 3D seismic geomechanics, representing a first step in minimizing drill time for cost reduction.
Quantitative mapping of stress heterogeneity allows for acreage high-grading ahead of the drill bit to identify completion quality "sweet spot" fairways and areas more prone to frac hits and parent-child issues. Cookie-cutter development strategies assume subsurface isotropy and fail to account for rock heterogeneity.
Pre-drill parameterization of fracture geometry models for horizontal landing, well spacing, and engineered treatment design requires an anisotropic in-situ stress measurement defining the vertical and lateral heterogeneity of geomechanical properties defined by the seismic, along horizontal and vertical wellbores.
Unconventional exploration and production (E&P) companies are now focused on strong balance sheets and free cash flows more so than ever. This speaks to capital efficiency across the value chain, involving key improvements in well spacing, completions design, and development planning (McKinsey & Company, 2020). This is particularly critical as E&P companies continue to assume isotropic subsurface geology, resulting in frac interference, parent-child phenomena, and overall marginal field development.
Hart Energy (2020) further emphasizes a necessity for optimal development and successful experimentation that is technology driven, involving technical managers, engineers, and geoscientists to identify transformation opportunities going forward. That said, SciCat® has developed proprietary and award winning seismic driven technology that measures in-situ 3D minimum horizontal stress which is the key rock parameter that governs hydraulic fracture stimulation of tight oil and gas formations.
After 20 years in the oil and gas E&P industry, Dr. Michael Shoemaker decided to change directions in early 2020, and share his passion and expertise by helping others, so he started SciCat®. Michael is a proven oil and gas finder in both unconventional and conventional plays worldwide with extensive Permian Basin experience.
SciCat's innovative technology and workflow were recently peer-reviewed and published in The Leading Edge (2019), and has been presented at numerous venues (2019) including URTeC, Permian Basin Completions Congress, GSH, SPE Permian, PBGS, and WTGS.
Dr. Shoemaker holds a PhD in Geophysics from the Missouri University of Science and Technology (formally the University of Missouri-Rolla), has authored over 60 publications and is the recipient of the 2020 Levorsen Memorial Award for innovation in subsurface exploration.
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