A strain-induced permeability model was used to describe the anisotropic permeability change of the sandy-shale caused by steam injection. Pre-existing planes of weakness will be tough if not impossible to open in the direction perpendicular to maximum horizontal stress, where horizontal stress ratios are high. Prerequisites: Engineering Mechanics 319 and Petroleum and Geosystems Engineering 301 with a grade of at least C- in each. Previous studies have illustrated that it is possible to delineate the extent of the reservoir dilation from the surface heave measurement using inverse technique. A Poroelastic Multicomponent Reservoir Simulator. However, the problem remains one of replacing the dependency on effective stress by one on pressure only. A strain-induced permeability model is developed based on the analysis of the grain fabric of intact and sheared oil sand specimens using a thin section imaging method.
The color shows the faulting regime the same as denoted in Figure 5; black is unknown regime. . This interdisciplinary course encompasses the fields of rock mechanics, structural geology, earthquake seismology and petroleum engineering to address a wide range of geomechanical problems that arise during the exploitation of oil and gas reservoirs. In addition, John Logel, Eric Andersen, Geoff Rait, Dave Gray, Jared Atkinson, and Rob Kendall have all provided help and insight into these issues over the past 2 years. This assumption holds true in most areas, except near large geologic structures such as faults, salt domes, and igneous intrusions where more complicated stress models are needed to describe the stresses within the earth. A Statement of Accomplishment will be given to those who obtain more than 70% of the maximum points on the 8 homework assignments. A sandy-shale layer with thickness of 1 metre is located 2 metre above a horizontal injection well.
Developments in Geotechnical Engineering, O. This occurs wherever at least one of the horizontal stresses is greater than the vertical stress, i. When will my Statement of Accomplishment arrive? How To Approximate Effects of Geomechanics in Conventional Reservoir Simulation. We have mud weight to balance this dis-equilibrium, but commonly this is not enough to stop breakout or wellbore instability completely. Figures 7-9 all point to the fact that stress direction and magnitude matter in a way not fully appreciated by many.
I will concentrate primarily on how properties that we can derive from seismic using currently available techniques can be used for stimulation modeling and proppant selection. A Brazilian test was conducted in this study for determining Et and Ec of the Montney shale in its foliation plane. Unconsolidated sands do not exhibit elastic-brittle behavior. Although easier and cheaper to produce, the gas production from these conventional sources is declining. Given what has been outlined in this paper, it is evident that P-wave and multi-component seismic can provide insights into geomechanics and engineering problems that are abundant in unconventional resource exploration.
Generalized cube showing simplified geomechanical modeling inputs. Most stimulation simulators use modifications of this equation to account for tectonic effects, but these are in most cases poorly constrained and often just calibrations to existing stress data minifracture tests, leak off tests, etc. The same principles can be also applied to model hydraulically induced fractures being represented by dynamically changing transmissibility multipliers in the potential fracture plane. It considers key practical issues such as prediction of pore pressure, estimation of hydrocarbon column heights and fault seal potential, determination of optimally stable well trajectories, casing set points and mud weights, changes in reservoir performance during depletion, and production-induced faulting and subsidence. Compaction Within the South Belridge Diatomite. This figure shows breakout in a horizontal wellbore in a normal faulting regime, where overburden is the maximum stress.
While it is not required to purchase the Reservoir Geomechanics textbook for this course, it is recommended. Fatimah has a Master of Science in Geophysics from Stanford where she began her work on laboratory characterization of shale anisotropy. Most of the fast shear S1 direction is in the regional direction of maximum horizontal stress as derived from the World Stress Map Heidbach et al; 2008. The minimum horizontal stress can be estimated using leak off tests, offset completion data, or mini fracture tests within the wellbore. Zoback has received a number of awards and honors, including the 2006 Emil Wiechert Medal of the German Geophysical Society and the 2008 Walter H. Historically, has accounted for by simple use of a time-invariant rock compressibility c R , spatially constant or variable. Presented at the Canadian International Petroleum Conference, Calgary, Alberta, Jun 4 - 8, 2000 2000.
New York City: Elsevier Applied Science. Fluid partition into each fracture is implemented using a wellbore fully coupled with the fracture elements. Bucher Medal of the American Geophysical Union. However, the changes in porosity and permeability are more pronounced when rock failure occurs, such as in compacting reservoirs or in high-pressure injection operations, and these processes require use of more complex, coupled geomechanical modeling. The long axis of the survey is E-W and survey area is 10 km 2. Ankush Singh, Graduate Teaching Assistant Ankush Singh is a 2nd year Ph. A reservoir wide pore pressure distribution can be derived using velocity information from 3D seismic data and be calibrated with downhole pressure measurements Modular Dynamics Tester.
There are detailed case studies on 3D and 4D reservoir geomechanics, showing the geomechanical influence of pressure changes in the reservoir. At the same time, field hydraulic fracturing tests data provide valuable information regarding the mechanical and hydraulic behaviours of the reservoir formation. The borehole that we are drilling disrupts that equilibrium and causes stress to redistribute around the borehole. The major drawback of the use of compaction tables is that the dependence on stress indicated in Eq. These constraints can be incorporated into coupled models, and additional modules can be integrated e. However, the stress state in the Fort Worth Basin is one that is, for the most part, in a normal faulting regime there are some exceptions to this ; and the magnitudes of the horizontal stresses are nearly equal.
Predictions integrate data from a variety of sources—including 3D surface seismic, well logging, core data, and well test data, and can be calibrated with monitoring data such as 4D seismic, microseismic, repeat well logging, subsidence measurements, and wellbore stability events. Breakouts occur in the direction of minimum horizontal stress, as the maximum compression where breakout occurs in the wellbore happens 90 degrees from the maximum horizontal stress in most cases. The system of non-linear equations of fluid flow and fracture deformation are solved rapidly for large-scale problem in a fully-coupled manner. Given that not all problems require use of geomechanics, and the cost of the study may increase dramatically, it is important to be able to identify when coupled simulation is needed, and what approximations can be made without compromising the answers. . Unconventional in this case refers to tight sands and shales containing oil or gas that require stimulation to produce at economic rates.
He is the 2013 recipient of the Louis Néel Medal, European Geosciences Union and named an Einstein Chair Professor of the Chinese Academy of Sciences. Therefore, reservoir description may be changing in time because of geomechanics; this aspect has been ignored in coupled models to date. While these couplings physically exist to some extent in all reservoirs, they can be often ignored or approximated when the reservoir behaves elastically. On reloading, there is a hysteretic effect. Advances in Coupled Geomechanical and Reservoir Modeling With Applications to Reservoir Compaction. This paper also addresses how this anisotropy in tensile strength could affect the pattern of hydraulically induced fractures in the field.