Based on the finite element software abaqus, considering the rock fluid solid coupling effect, and with the initial stress of vertical. Wellbore shrinkage during drilling in methane hydrate. Finally, based on borehole stability mechanical models, the effects of well trajectory on borehole stability were analyzed. In this paper, a thermohydromechanical thm fullycoupled model of formation and wellbore is established. Ensuring wellbore stability with geomechanics and pore pressure. Guidelines for papers to be presented at the abaqus. According to the coupled theory of mixtures for rock medium, a coupled thermalhydraulicmechanical thm model is proposed and derived, which is coded with matlab language and abaqus software as the solver. This is underpinned by the numerous factors that must be considered in order to ensure safety and. Wellbore stability requires a proper balance between theuncontrollable factors of earth stresses, rock strength, and pore pressure, andthe controllable factors of wellbore fluid pore pressure, and the controllablefactors of wellbore fluid pressure and mud chemical composition. But, because the current state of a plastic material is a function of its stressstrain history, fully 3d plastic models require numerical methods. Features and benefits n connect to dassault systemes. Prediction of wellbore stability using 3d finite element model in a shallow unconsolidated heavyoil sand in a kuwait field k. Qra approach to stability analysis the range of safe mud weights to maintain wellbore stability lies between the wellbore collapse pressure and the lost circulation pressure.
Numerical simulations for wellbore stability and integrity. Finite element modeling of the stability of single wellbores. Abaquscae, or c omplete a baqus e nvironment a backronym with an obvious root in c omputer a ided e ngineering. Pdf prediction of wellbore stability using 3d finite. Using wellcheck, presscheck, and sfib modules from the acclaimed bhigmi jewelsuite geomechanics software, our office and onsite wellbore stability and geomechanics specialists can model, monitor and forecast wellbore stability of the borehole as it is being drilled, and give rt input into any potential instability issues. The abaqus unified fea product suite has an unsurpassed reputation for technology, quality and reliability. Therefore, wellbore stability modeling can be done more accurately in young rocks using plastic models. This project is aimed at improving the accuracy of wellbore stability analysis. Modelling of timedependent wellbore collapse in hard brittle. The software output was calibrated and validated with the observed failed wellbore condition in selected drilled.
Numerical modeling of geomechanical processes related to. The performance of stochastic designs in wellbore drilling. Wellbore stress example, reservoir geomechanics youtube. Wellbore stability is considered when the well diameter fits the bit sizes and it remains constant while drilling.
The wellbore stability model implemented in the psi software combines input parameters describing formation conditions, formation properties and wellbore data to predict the stability of the well over time. In recent years, the lithologic traps in a middepth formation are the focus of oil or gas exploration and development for eastern oilfields in china. The current wellbore stability analyses for analytical solutions are mostly based on the linear elastic or poroelastic theory. By using abaqus software, the temperature difference induced by thermal. Polyaxial strength test data of five rocks are used to examine the mohrcoulomb, druckerprager, modified lade, mogicoulomb and threedimensional 3d hoekbrown criteria regarding their. Wellbore stability, casing integrity, and sanding features and benefits n connect to dassault systemes abaqus software link seamlessly with abaqus, the leading finiteelement mechanical simulator set up and execute complex numerical simulations quickly the baker hughes jewelsuite generate precise, highperformance. The shahejie formation develops thick hard brittle shale, and the wellbore instability problem is prominent due to obvious hydration effect for long immersion time during drilling. Quite often the operating parameters are set to certify. Through the analysis of laboratory tests and field test results. Modeling and mesh generation are operated in the abaqus software, and. However, these costs can be significantly reduced through the application of. Jan 22, 2014 wellbore stability problems are known to cost the oil and gas industry billions of dollars each year.
How reservoir geomechanics is being addressed by simulia. Water injection and stimulation analyses for ensuring optimal oil. In the process of drilling, the economic losses caused by wellbore instability reaches more than one billion. Wellbore stability analysis acts an important role in the drilling design to avoid pipestuck, lost circulation and the other instabilityinduced problems. The formation is simplified as a poroelastic medium. A numerical investigation of wellbore stability problems using an elastoplastic model. Simuleon enables innovation by providing highend simulation software and consultancy introduction to nonlinear analysis workshop. Maintaining wellbore stability is an important issue in oil and gas industry 110. Optimizing drilling performance by wellbore stability evaluation and directional drilling practices. We concluded that using these two methods simultaneously can assist in the stability of wellbores effectively which result cost savings and minimizing time overruns on drilling projects. Currently, the exploration of natural gas hydrates nghs is regarded as a worldwide research focus. The casing and cement sheath in injection and production wells are embedded in the formation. The investigation is based on finite element threedimensional modeling using the commercial software abaqus. In the process of drilling, the economic losses caused by wellbore instability reaches more than one billion dollar every year, and the lost time is accounting for over 40% of all drilling related nonproductive time.
Finite element modeling of the stability of single. Introduction to wellbore stability analysis youtube. Wellbore stability requires a proper balance between theuncontrollable factors of earth stresses, rock strength, and pore pressure, andthe controllable factors of wellbore fluid pore pressure, and the. Conventional wellbore trajectory planning is commonly based on an andersonian state of stress sos and the optimum well azimuth and inclination for a specific depth. Implementation of bounding surface model into abaqus and. However, these costs can be significantly reduced through the application of comprehensive geomechanical models. Petroleum geomechanics is the branch of engineering dealing with the mechanical properties and behavior of geological formations which influence the exploration, development, and production of oil and gas. Numerical simulation of hydraulic fracture propagation. The overburden pressure resulting from the rock column atop becomes larger as the well depth is increasing. Finally, a fluidsolid coupling simulation analysis was made by use of the abaqus finite element software. This paper is relevant and is appropriate in the oil and gas industry. Zehner, method and apparatus for generation of 3d graphical borehole analysis.
The integration algorithm for the bounding surface model is implemented into the finite element analysis commercial program, abaqus, through the material interface of umat user defined material subroutine, and then used for the analysis of wellbore stability problem. Unfortunately, wellbore stability problems, such as unexpected low fracture gradient, are relatively common while drilling close and out of these salt structures. Mar 26, 2019 however, wellbore shrinkage can be a main factor influencing drilling safety in methane hydrate reservoirs, especially wellbore stability of horizontal wells in methane hydrate reservoirs. Stresses generated for the lower limit of the mud weight window. Geomechanical modeling of insitu stresses around a borehole. Nov 15, 2016 they provide critical input into the placement of a well and play a vital role in designing the most cost effective mud and casing programs, which in turn ensure stability of the wellbore and aid. Accurate wellbore collapse initiation pressure is necessary for a robust wellbore bridging study. Comprehensive wellbore stability analysis utilizing. It has been adopted by major corporations across all engineering disciplines as an integral.
Wellbore stability problems are known to cost the oil and gas industry billions of dollars each year. The training consists of theory, trainer examples and clear workshops to exercise what was tought. The program lies within development tools, more precisely distribution. Wellbore stability is greatly affected by various factors, such as the formation fluid, and the properties and temperature of the drilling fluid, and is critical to petroleum drilling. They provide critical input into the placement of a well and play a vital role in designing the most cost effective mud and casing programs, which in turn ensure stability of the wellbore and aid. The name and logo of this software are based on the abacus. The effect of coupled thermoporoelastic behavior on hydraulic fracture propagation is of much interest in geothermal and petroleumrelated geomechanics problems such as wellbore stability and hydraulic. Wellbore stability and geomechanics hxr drilling services. Analysis of vertical, horizontal and deviated wellbores. In many cases, wellbore stability analysis can be carried out with very simple models that are timeindependent and relate stress and pore pressure, only through the effective stress law. They provide critical input into the placement of a well and play a vital role in designing the most cost effective mud and casing programs, which. Upon the good verification results, the code is applied to an underbalanceddrilling case. However, the conventional linear elastic model used by the industry is too conservative in predicting the mud weight window. Himmelberg, nevan christopher, numerical simulations for wellbore stability and.
Introducing optimized validated meshing system for wellbore. An industrial geomechanical software was used to build a mechanical earth model mem. We found that the chemical properties of drilling fluid, wellbore trajectory and. A numerical investigation of wellbore stability problems using an. The relationship between the intermediate principle stress and the rate of sanding documented in relevant literatures may. You can launch this pc program on windows xpvista7810 32 and 64bit. Mechanical responses of formation and wellbore induced by. In constrast to this, geomechanical instability refers to mechanical conditions such as wellbore collapse or failure.
Wellbore stability analysis for trouble free drilling onepetro. According to the coupled theory of mixtures for rock medium, a coupled thermalhydraulicmechanical thm model is proposed and derived, which is coded with matlab language and abaqus software. In this paper, the creep shrinkage law of wellbore when drilling through hydrate reservoirs in cold regions is studied, and the influencing factors and. Wellbore shrinkage during drilling in methane hydrate reservoirs. Basic introduction to wellbore stability analysis designed and presented by sam saeed hashemi. However, the conventional linear elastic model used by the. The heterogeneity and sometimes unpredictable behaviour of underground systems increases the sensitivity of drilling activities. Borehole stability and field stress analysis with azimuthal. The introduction course gives you a nice overview of the possibilites. Azim1, sankar chowdhuri1, salah alanezi1, anar abdulkarim2, ahmet aki2, and.
Abaqus fea formerly abaqus is a software suite for finite element analysis and computeraided engineering, originally released in 1978. Introducing optimized validated meshing system for. Pbore3d is a userfriendly software that analyzes and. Then the wellbore stability is simulated with the proposed model by considering the drilling unloading, fluid flow, and thermal effects between the borehole and the formation. Wellbore stability in oil and gas drilling with chemical. Abaqusstandard now provides a capability to model solidstate phase transformation that can be used to simulate metalsbased additive manufacturing and heat treatment processes. Thermoporoelastic fracture propagation modeling with.
Lost returns and wellbore stability analyses to ensure reliable and efficient drilling processes. The software is structured to assist drilling engineers to design a wellbore drilling program for mudweight window, mud salinity, and depthgradient analyses. Analysis of vertical, horizontal and deviated wellbores stability. This solution is valid when it is assumed the assumptions of plane strain condition and material with behavior. Abaqus explicit now provides nonquadratic yield surfaces for plasticity based on the criteria proposed by barlat. Mar 18, 2009 prediction of wellbore stability using 3d finite element model in a shallow unconsolidated heavyoil sand in a kuwait field k. This is underpinned by the numerous factors that must be considered in order to ensure safety and productivity. Wellbore collapse pressure pc is the mud pressure below which the entire wellbore wall becomes unstable, which occurs when zones of compressive wellbore. The key factor to control the wellbore stability is the rate of sanding. Wellbore drilling operations frequently entail the combination of a wide range of variables. Borehole instabilities can be encountered at any stage in the life of a well and they are the main cause of drilling difficulties, resulting in substantial expenditures, expensive loss of time, sometimes even in the. When drilling overbalance through a porous and permeable formation, there is flow of wellbore fluid into the. However, wellbore shrinkage can be a main factor influencing drilling safety in methane hydrate reservoirs, especially wellbore stability of horizontal wells in methane hydrate reservoirs.
By analyzing the several key factors of the impacts of pullback speed and strata on wellbore. Ensuring wellbore stability with geomechanics and pore. The wellbore stability model implemented in the psi software combines input parameters describing formation conditions, formation properties and wellbore data to predict the stability of the well over. Then the wellbore stability is simulated with the proposed model. This dissertation describes investigation of the stability of single holes and multilateral junctions in order to optimize their design. The insights from these models were used to guide the prediction of the onset of shear failure wellbore instability and consequently the determination of the lower bound mud weight window for safe drilling operations in conventional wells. Coupled thm modelling of wellbore stability with drilling unloading.
Wellbore stability in geomechanics nottingham eprints. Oct 08, 20 different states of vertical, horizontal and deviated. Compared with coaxial model, noncoaxial model gives more pessimistic results. Abaqus standard now provides a capability to model solidstate phase transformation that can be used to simulate metalsbased additive manufacturing and heat treatment processes. Mud weight window considering the creep effect for the lower limit.
Hydrostatic pressure application tutorial hdpe water. Mechanical study on the wellbore stability of horizontal. Ensuring wellbore stability with geomechanics and pore pressure prediction. The wellbore is regarded as unstable if the determined elasticporoelastic stresses. Study on the criterion and influence of pipeline laying. Mechanical responses of formation and wellbore induced by water injection for enhanced geothermal system. Numerical wellbore stability numerical wellbore stability traditionally, the wellbore stability is performed based on analytical solution to calculate the stress state around the wellbore. Combining and and and rearranging the equation, the failure function, will be failure occurs if.
Psi estimates the probability for mechanical failure inside the borehole wall. The mogicoulomb parameters can be related to coulomb failure parameters as follows. The 1dmem is the backbone of every geomechanical workflow for which it provides the stress field, pore pressure, and mechanical properties. However, it was found that the influence of noncoaxiality on wellbore stability depended on initial conditions of wellbore.
Probabilistic approach in wellbore stability analysis. We concluded that using these two methods simultaneously can assist in the stability of wellbores effectively which result cost savings. Well whole stability is the key of radial well construction. Nor do these models account for thermal and chemical effects and their relationships to pore pressure and stress. Mechanicalthermalchemical coupled research of wellbore. Wellbore stability analysis for trouble free drilling. Analysis of factors influencing the stability of multi. Then the wellbore stability is simulated with the proposed model by considering the drilling unloading, fluid flow, and thermal effects. The insights from these models were used to guide the prediction of the onset of shear failure wellbore instability. We found that the chemical properties of drilling fluid, wellbore trajectory and temperature has a great influence on wellbore stability, and the impact of temperature changes and of well trajectory are the largest factor. Pbore3d is a userfriendly software that analyzes and simulates the timedependent effects on wellbore stability while drilling. A third problem considered as wellbore instability, is sanding production in the completion stage. These do not account for the fact that stress changes induce pore pressure changes, and vice versa.
It also includes wellbore scale phenomena, such as wellbore stability during drilling, hydraulic fracturing, formationcasing interaction during production, sand production, and waste injection. The stability of single holes and multilateral junctions was analyzed at different orientations. In particular, the orientation of the well has great relevance. Psborehole stability and field stress analysis with azimuthal loggingwhiledrilling technology. Coupled thm modelling of wellbore stability with drilling. Using wellcheck, presscheck, and sfib modules from the acclaimed bhigmi jewelsuite geomechanics software, our office and onsite wellbore stability and geomechanics specialists can. It is a software application used for both the modeling and analysis of mechanical components and assemblies preprocessing and visualizing the finite element analysis result. May 24, 2015 basic introduction to wellbore stability analysis designed and presented by sam saeed hashemi.
The noncoaxiality theory is incorporated into casm to analyse the wellbore stability. The techlog wellbore stability module comprises mechanical earth model 1dmem building, wellbore stability, sand management, and fracture stability computation. This software applies the coupled fluid flow and rock deformation analyses in the studies of wellbore stability and drilling mud design. Each month training is planned and we are flexible to change that scheme for your convenience. A numerical investigation of wellbore stability problems. During drilling, there are other sources which can also contribute to the development of stability problems. Our antivirus analysis shows that this download is clean.
435 831 619 640 1396 711 1131 1085 505 1484 151 1432 551 1266 572 429 77 1375 549 352 1564 319 1245 231 1528 1311 980 306 169 763 1478 606 187 887 96 1232 371 441