3D numerical simulation of injection into a porous natural gas storage

2011 ◽  
Vol 51 (1) ◽  
pp. 653
Author(s):  
Amin Chamani ◽  
Vamegh Rasouli
Keyword(s):  
Natural Gas ◽  
Land Surface ◽  
Fluid Pressure ◽  
Fault Reactivation ◽  
Numerical Code ◽  
Displacement Fields ◽  
Stress Regime ◽  
Wellbore Instability ◽  
Increasing Demand ◽  
Rock Mechanical Properties

The increasing demand for the consumption of natural gas has attracted the interest to store natural gas in depleted reservoirs. Natural gas is injected into the depleted reservoir and then produced once needed to be supplied to the consumers through pipelines. Changes of reservoir fluid pressure due to injection/ depletion will result in the local changes of stress regime inside the reservoir as well as the surrounding rocks. These stress fluctuations will primarily lead to the deformations and changes of the loads exerted on the wellbore. This can potentially trigger hazardous events such as considerable land surface movements, wellbore instability and casing collapse, fault reactivation, and cap rock failure. Therefore a good knowledge of reservoir geomechanics is required when planning storage of natural gas in a depleted reservoir. In this paper the concept of effective stress and pore pressure will be reviewed. A 3D finite element (FE) numerical modelling technique is developed to investigate the changes in stresses and displacements either during the injection or the depletion in a complete isotropic elastic media. The numerical code is used to simulate the injection-induced stress and displacement fields at a field scale for a hypothetical model with an embedded porous formation. The effect of formation rock mechanical properties such as Young’s modulus is also investigated through a series of sensitivity analysis. The results are presented and interpreted and various conclusions are made.

scholarly journals Assessing Natural Gas Versus CO2 Potential Underground Storage Sites in Greece: A Pragmatic Approach †

2022 ◽  
Vol 5 (1) ◽  
pp. 98
Author(s):  
Vagia Ioanna Makri ◽  
Spyridon Bellas ◽  
Vasilis Gaganis
Keyword(s):  
Natural Gas ◽  
Co2 Storage ◽  
Sedimentary Basins ◽  
Hydrocarbon Exploration ◽  
Greenhouse Gas Mitigation ◽  
Underground Storage ◽  
Pragmatic Approach ◽  
Increasing Demand ◽  
Salt Caverns

Although subsurface traps have been regularly explored for hydrocarbon exploration, natural gas and CO2 storage has drawn industrial attention over the past few decades, thanks to the increasing demand for energy resources and the need for greenhouse gas mitigation. With only one depleted hydrocarbon field in Greece, saline aquifers, salt caverns and sedimentary basins ought to be evaluated in furtherance of the latter. Within this study the potential of the Greek subsurface for underground storage is discussed. An overview and re-evaluation of the so-far studied areas is implemented based on the available data. Lastly, a pragmatic approach for the storage potential in Greece was created, delineating gaps and risks in the already proposed sites. Based on the above details, a case study for CO2 storage is presented, which is relevant to the West Katakolo field saline aquifer.

scholarly journals The influence of fault reactivation on injection-induced dynamic triggering of permeability evolution

2020 ◽  
Vol 223 (3) ◽  
pp. 1481-1496
Author(s):  
Elif Cihan Yildirim ◽  
Kyungjae Im ◽  
Derek Elsworth
Keyword(s):  
Pore Pressure ◽  
Fluid Pressure ◽  
Fault Reactivation ◽  
Permeability Evolution ◽  
Fracture Permeability ◽  
Permeability Enhancement ◽  
Pressure Pulses ◽  
Fracture Sealing ◽  
Permeability Increase ◽  
Pressure Driven

SUMMARY Mechanisms controlling fracture permeability enhancement during injection-induced and natural dynamic stressing remain unresolved. We explore pressure-driven permeability (k) evolution by step-increasing fluid pressure (p) on near-critically stressed laboratory fractures in shale and schist as representative of faults in sedimentary reservoirs/seals and basement rocks. Fluid is pulsed through the fracture with successively incremented pressure to first examine sub-reactivation permeability response that then progresses through fracture reactivation. Transient pore pressure pulses result in a permeability increase that persists even after the return of spiked pore pressure to the null background level. We show that fracture sealing is systematically reversible with the perturbing pressure pulses and pressure-driven permeability enhancement is eminently reproducible even absent shear slip and in the very short term (order of minutes). These characteristics of the observed fracture sealing following a pressure perturbation appear similar to those of the response by rate-and-state frictional healing upon stress/velocity perturbations. Dynamic permeability increase scales with the pore pressure magnitude and fracture sealing controls the following per-pulse permeability increase, both in the absence and presence of reactivation. However, initiation of the injection-induced reactivation results in a significant increase in the rate of permeability enhancement (dk/dp). These results demonstrate the role of frictional healing and sealing of fractures at interplay with other probable processes in pore pressure-driven permeability stimulation, such as particle mobilization.

APPLICATION OF GUIDELINE CHARTS IN DECISIONMAKING ON WELL TRAJECTORY AND MUD WEIGHT PROGRAM

2001 ◽  
Vol 41 (1) ◽  
pp. 609
Author(s):  
X. Chen ◽  
C.P. Tan ◽  
C.M. Haberfield
Keyword(s):  
Stability Analysis ◽  
Case Studies ◽  
In Situ Stress ◽  
Wellbore Stability ◽  
Material Strength ◽  
Stress Regime ◽  
Wellbore Instability ◽  
Well Trajectory

To prevent or minimise wellbore instability problems, it is critical to determine the optimum wellbore profile and to design an appropriate mud weight program based on wellbore stability analysis. It is a complex and iterative decisionmaking procedure since various factors, such as in-situ stress regime, material strength and poroelastic properties, strength and poroelastic anisotropies, initial and induced pore pressures, must be considered in the assessment and determination.This paper describes the methodology and procedure for determination of optimum wellbore profile and mud weight program based on rock mechanics consideration. The methodology is presented in the form of guideline charts and the procedure of applying the methodology is described. The application of the methodology and procedure is demonstrated through two field case studies with different in-situ stress regimes in Australia and Indonesia.

Implications of accurate geomechanical modelling and systematic core testing for sanding evaluation and sand control decisions – a case study from Perth Basin

2020 ◽  
Vol 60 (1) ◽  
pp. 267
Author(s):  
Sadegh Asadi ◽  
Abbas Khaksar ◽  
Mark Fabian ◽  
Roger Xiang ◽  
David N. Dewhurst ◽  
...  
Keyword(s):  
Management Strategies ◽  
Mechanical Tests ◽  
Well Test ◽  
Sand Production ◽  
Gas Field ◽  
Stress Regime ◽  
Full Field ◽  
Field Development ◽  
Sand Control ◽  
Rock Mechanical Properties

Accurate knowledge of in-situ stresses and rock mechanical properties are required for a reliable sanding risk evaluation. This paper shows an example, from the Waitsia Gas Field in the northern Perth Basin, where a robust well centric geomechanical model is calibrated with field data and laboratory rock mechanical tests. The analysis revealed subtle variations from the regional stress regime for the target reservoir with significant implications for sanding tendency and sand management strategies. An initial evaluation using a non-calibrated stress model indicated low sanding risks under both initial and depleted pressure conditions. However, the revised sanding evaluation calibrated with well test observations indicated considerable sanding risk after 500 psi of pressure depletion. The sanding rate is expected to increase with further depletion, requiring well intervention for existing producers and active sand control for newly drilled wells that are cased and perforated. This analysis indicated negligible field life sanding risk for vertical and low-angle wells if completed open hole. The results are used for sand management in existing wells and completion decisions for future wells. A combination of passive surface handling and downhole sand control methods are considered on a well-by-well basis. Existing producers are currently monitored for sand production using acoustic detectors. For full field development, sand catchers will also be installed as required to ensure sand production is quantified and managed.

scholarly journals Chemical Effect on Wellbore Instability of Nahr Umr Shale

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Baohua Yu ◽  
Chuanliang Yan ◽  
Zhen Nie
Keyword(s):  
Drilling Fluid ◽  
Ionic Concentration ◽  
Chemical Effect ◽  
Drilling Fluids ◽  
Collapse Pressure ◽  
Wellbore Instability ◽  
Sealing Capacity ◽  
Engineering Data ◽  
Forward Engineering ◽  
Rock Mechanical Properties

Wellbore instability is one of the major problems that hamper the drilling speed in Halfaya Oilfield. Comprehensive analysis of geological and engineering data indicates that Halfaya Oilfield features fractured shale in the Nahr Umr Formation. Complex accidents such as wellbore collapse and sticking emerged frequently in this formation. Tests and theoretical analysis revealed that wellbore instability in the Halfaya Oilfield was influenced by chemical effect of fractured shale and the formation water with high ionic concentration. The influence of three types of drilling fluids on the rock mechanical properties of Nahr Umr Shale is tested, and time-dependent collapse pressure is calculated. Finally, we put forward engineering countermeasures for safety drilling in Halfaya Oilfield and point out that increasing the ionic concentration and improving the sealing capacity of the drilling fluid are the way to keep the wellbore stable.

scholarly journals Geomechanical Analysis to Avoid Serious Drilling Hazards in Zubair Oilfield, Southern Iraq

2020 ◽  
pp. 1994-2003
Author(s):  
Shaban Dharb Shaban ◽  
Hassan Abdul Hadi
Keyword(s):  
Gamma Ray ◽  
Mechanical Test ◽  
Horizontal Wells ◽  
Failure Criteria ◽  
Horizontal Stress ◽  
Wellbore Instability ◽  
Geomechanical Analysis ◽  
Safe Mud Window ◽  
Rock Mechanical Properties ◽  
Minimum Horizontal Stress

Zubair oilfield is an efficient contributor to the total Iraqi produced hydrocarbon. Drilling vertical wells as well as deviated and horizontal wells have been experiencing intractable challenges. Investigation of well data showed that the wellbore instability issues were the major challenges to drill in Zubair oilfield. These experienced borehole instability problems are attributed to the increase in the nonproductive time (NPT). This study can assist in managing an investment-drilling plan with less nonproductive time and more efficient well designing.       To achieve the study objectives, a one dimension geomechanical model (1D MEM) was constructed based on open hole log measurements, including Gamma-ray (GR), Caliper (CALI), Density (RHOZ), sonic compression (DTCO) and shear (DTSM) wave velocities , and Micro imager log (FMI). The determined 1D MEM components, i.e., pore pressure, rock mechanical properties, in-situ principal stress magnitudes and orientations, were calibrated using the data acquired from repeated formation test (RFT), hydraulic fracturing test (Mini-frac), and laboratory rock core mechanical test (triaxial test). Then, a validation model coupled with three failure criteria, i.e., Mohr-Coulomb, Mogi-Coulomb, and Modified lade, was conducted using the Caliper and Micro-imager logs. Finally, sensitivity and forecasting stability analyses were implemented to predict the most stable wellbore trajectory concerning the safe mud window for the planned wells.    The implemented wellbore instability analysis utilizing Mogi-Coulomb criterion demonstrated that the azimuth of 140o paralleling to the minimum horizontal stress is preferable to orient deviated and horizontal wells. The vertical and slightly deviated boreholes (1ess than 30o) are the most stable wellbores, and they are recommended to be drilled with 11.6 -12 ppg mud weight. The highly deviated and horizontal wells are recommended to be drilled with a mud weight of 12-12.6 ppg.

Nonlinear Effects of Wave Heights on Coupled Sloshing and Seakeeping Responses

2018 ◽  
Author(s):  
Xin Wang ◽  
Makoto Arai ◽  
Gustavo Karuka
Keyword(s):  
Natural Gas ◽  
Numerical Method ◽  
Three Dimensional ◽  
Nonlinear Effects ◽  
Numerical Code ◽  
Ship Motions ◽  
Impulse Response Functions ◽  
Weakly Nonlinear ◽  
Wave Heights ◽  
The Time Domain

With increased activities in natural gas transportation and offshore exploration in the past decades, assessment of sloshing in liquefied natural gas (LNG) tanks has become an important practical issue. In this paper, we focus on the deterministic calculation of the coupled sloshing and ship motions in regular wave conditions. An in-house numerical code is used to solve the seakeeping problem coupled with the sloshing dynamics. The numerical method adopts a weakly nonlinear approach using impulse response functions for the seakeeping problem. Nonlinear Froude-Krylov and hydrostatic forces are directly evaluated in the time domain. A three-dimensional finite difference method is applied to solve the sloshing problem. The numerical method is validated by comparing with experimental results in the literature. The developed numerical method is used to analyze the nonlinear effects of wave heights.

Compiling and correlating paleostress fields across Central Europe - A paleostress chart for northern Bavaria and adjacent areas

2021 ◽  
Author(s):  
Florian Duschl ◽  
Tobias Stephan ◽  
Saskia Köhler ◽  
Daniel Köhn ◽  
Harald Stollhofen ◽  
...  
Keyword(s):  
Central Europe ◽  
Plate Tectonics ◽  
Structural Data ◽  
Original Data ◽  
Fault Reactivation ◽  
Detailed Knowledge ◽  
Temporal And Spatial Distribution ◽  
Stress Regime ◽  
Tectonic Events ◽  
Temporal And Spatial

<p>Detailed knowledge on the temporal and spatial distribution of faults and fractures not only reveals the geodynamic and tectonic evolution of the lithosphere. It is also of increasing importance with regard to economic, social, and environmental challenges such as nuclear waste disposal, gas storage, geothermal energy, natural hazards, and mineral resource exploration. In this context reliable data on both timing and kinematics of deformation and their regional impact on faulting and fracture formation provide crucial information to evaluate exploration, storage, and production risks, which in turn stresses the need for comprehensive data on paleostress fields and their influence on deformation, fault reactivation, fluid activity, and hydrothermal mineralization.</p><p>In this study we present a first comprehensive approach to compile and visualize information on the crustal paleostress field of Central Europe with a focus on northern Bavaria and adjacent areas. The compilation includes published structural data from kinematic paleostress analyses (e.g. fault-slip analysis, tectonic stylolites) and geo- and thermochronological ages of fracture mineralization and fault activity, respectively. The present compilation comprises structural records from more than 40 studies and age information from more than 100 geo-thermochronological studies. All structural data are categorized according to its tectonic stress regime and quality-ranked for reliability and comparability. The consequent linkage of structural data with thermochronological data wherever possible allows to correlate local paleostress fields and deformation patterns with regional to global tectonic events. As one result, the “Paleostress Chart for Northern Bavaria and adjacent Areas” visualizes the temporal and spatial evolution of several regions in Central Europe together with known tectonic phases, sedimentary unconformities and the plate kinematic framework since the Carboniferous.</p><p>This compilation may therefore help to better understand the timing and the spatio-temporal evolution of crustal stress patterns for tectonic events across Central Europe in the context of plate tectonics. </p><p>We aim to supplement and improve existing paleostress models on both, regional, and temporal scale by compiling published and original data. In the long term the database is intended as a continuing compilation where data from all across Central Europe are supposed to be included and refined subsequently.</p>

Periodic Fluid-mediated Weakening and Cementation Drives Cyclic Reorganisation of Shallow Basaltic Fault Zones

2021 ◽  
Author(s):  
Bob Bamberg ◽  
Richard Walker ◽  
Marc Reichow
Keyword(s):  
Host Rock ◽  
Slip Surface ◽  
Damage Zone ◽  
Fluid Pressure ◽  
Fault Zones ◽  
Fault Activity ◽  
Cyclic Activity ◽  
Fault Rock ◽  
Vein Formation ◽  
Rock Mechanical Properties

<p>Faults constitute the major source for mechanical and permeability heterogeneity in basaltic sequences, yet their architecture, and mechanical and physical properties remain poorly understood. These are however critical as basaltic reservoirs are becoming increasingly important for geothermal applications and CO<sub>2</sub> storage. Here we present a detailed microstructural- to outcrop-scale characterisation of mature (decametre-hectometre displacement) fault zones in layered basalts, in the Faroe Islands. Outcrop scale structures and fault rock distribution within the fault zone were mapped in the field to build 3D virtual outcrop models, with detailed characterisation of fault rock microstructure and petrology obtained from optical and SE-microscopy.</p><p>The fault zones exhibit evidence for cyclic activity controlled by fault internal fluid pressure variation. Deformation mechanisms in the core alternate between shear-compaction, evidenced by foliated cataclasite and gouge development, and dilatation through fluid overpressure, leading to hydrofracture and vein formation. Generally, a decametre-wide damage zone of Riedel faults is centrally transected by the fault core. The fault core is organised around a principal slip surface (PSS) hosted in a decimetre-wide principal slip zone (PSZ). The PSS and PSZ are dominantly composed of (ultra-) cataclasites, while the remaining core comprises anastomosing cataclastic bands bounding lenticular zones of various brecciated fault rocks. Further, PSS-proximal zones show significant late-stage dilatation by hydrothermal breccias or tabular veins with up to decimetre apertures, filled with early syntaxial to blocky zeolite and/or late coarse (≤ 1 cm) blocky calcite. The structures in the fault core are mutually overprinting, evidencing pulsed fault activity and PSS migration. The native plagioclase-pyroxene assemblage of the host rock is almost completely altered to zeolites and red-brown smectites in the fault core and along surrounding damage of mature faults, while lower displacement faults preserve the host rock mineralogy even in gouge. We infer that fluid flow along initial damage promotes alteration and the associated chemical weakening localises strain into a narrow PSZ. Here, fault activity is governed by alternating deformation styles – shear‑compaction and dilatation – suggesting changes in deformation mechanism linked to transient permeability decrease within the PSZ, followed by fluid overpressure and hydrofracture. Overall rock mechanical properties are thus governed by the combined effects of permanent chemical weakening and transient fluid-mediated mechanical weakening, alternating with cementation and healing, and will be explored by direct shear deformation experiments in the future.</p>

Integrated Reservoir Geomechanics Approach for Reservoir Management

2021 ◽  
Author(s):  
Vai Yee Hon ◽  
M Faizzudin Mat Piah ◽  
Noor 'Aliaa M Fauzi ◽  
Peter Schutjens ◽  
Binayak Agarwal ◽  
...  
Keyword(s):  
Pore Pressure ◽  
Water Injection ◽  
Fluid Pressure ◽  
Integrated Approach ◽  
Fault Slip ◽  
Fault Reactivation ◽  
Analytical Models ◽  
Reservoir Compaction ◽  
Stress Changes ◽  
Reservoir Geomechanics

Abstract An integrated 3D dynamic reservoir geomechanics model can provide a diverse 3D view of depletion-injection-induced field stress changes and the resulting deformation of both reservoir and overburden formations at various field locations. It enables the assessment of reservoir compaction, platform site subsidence, fault reactivation and caprock integrity associated with multiple production and injection reservoirs of the field. We demonstrated this integrated approach for a study field located in the South China Sea, Malaysia, which is planned for water injection for pressure support and EOR scheme thereafter. Reservoir fluid containment during water injection is an important concern because of the intensive geologic faulting and fracturing in the collapsed anticlinal structure, with some faults extending from the reservoirs to shallow depths at or close to the seafloor. Over 30 simulations were done, and most input parameters were systematically varied to gain insight in their effect on result that was of most interest to us: The tendency of fault slip as a function of our operation-induced variations in pore pressure in the reservoir rocks bounding the fault, both during depletion and injection. The results showed that depletion actually reduces the risk of fault slip and of the overburden, while injection-induced increase in pore fluid pressure will lead to a significant increase in the risk of fault slip. Overall, while depletion appears to stabilize the fault and injection appears to destabilize the fault, no fault slip is predicted to occur, not even after a 900psi increase in pore pressure above the pore pressure levels at maximum depletion. We present the model results to demonstrate why depletion and injection have such different effects on fault slip tendency. The interpretation of these geomechanical model results have potential applications beyond the study field, especially for fields with a similar geology and development plan. This is a novel application of 3D dynamic reservoir geomechanics model that cannot be obtained from 1D analytical models alone.

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