Integrated approach to pore pressure and fracture pressure. Pore pressure is notoriously difficult to predict and may vary significantly across a typical sedimentary basin. Techlog pore pressure prediction schlumberger software. The pressure of the subsurface formation fluids, commonly expressed as the density of fluid required in the wellbore to balance that pore pressure. However, a number of different compaction trends can be. Rokdoc rt is software for realtime well monitoring and risk management. Pore pressure models and predictions are important in well planning and safe completion and also play a crucial role in field development and in reservoir management. Using traditional methods to predict pore pressure in. This course introduces the attendee to the basics of the geopressure calculator gpc and fracture pressure calculator fpc modules within rokdoc. Free chemical and petroleum engineering spreadsheets calculate dexponent to predict pore pressure trends this excel spreadsheet calculates the dexponent, a parameter used by drilling engineers to investigate ppore pressure trends when drilling into overpressurized zones. The subsurface pore pressure buildup partitions are.
Petrospec technologiess pore pressure analysis tools. Modern modeling technologies for petroleum systems provide a complementary approach to traditional methods of pressure prediction. A normal pressure gradient might require 9 lbmgalus 1. Mar 28, 2016 pore pressure is notoriously difficult to predict and may vary significantly across a typical sedimentary basin.
Geomechanics and pore pressure prediction improve recovery and reduce exploitation costs. Without a proper input of the pore pressure an adjusted prediction becomes impossible to obtain for any geomechanical model. Calculate dexponent to predict pore pressure trends. Elfen fm case study predicting the paleo evolution of overpressured geological structures the project. Safer drilling log based pore and fracture pressure prediction. Pore pressure prediction in unconventional resources. Pdf integrated 1d workflow for porepressure prediction.
Understanding pore pressure prediction in unconventional plays is important for executing a safe drilling strategy and for accurate production modeling. When the indicator suggests porosity values that are higher than the trend, then abnormal pressures are suspected to be present. Pore pressure prediction and modeling using seismic velocities. Pore pressure prediction is the ability to create numerical formulas that mimic the subsurface pressure profile. In order to properly plan a well program and to drill a well, both safety and economically, knowledge and understanding of formation pressures and fracture gradients is essential. Elfen fm geomechanical forward modelling rockfield. Rokdoc is a comprehensive portfolio of rock physics, geopressure and geomechanics solutions for accelerating and improving subsurface predictions over asset lifetime. Challenges in pore pressure prediction for unconventional. Pore pressure prediction from well logs and seismic data. More information on our geomochanics analysis software is available from downunder geosolutions. Methods to determine pore pressure equivalent depth methods. An application of petroleum system modeling technology.
Pore pressure prediction an application of petroleum system modeling technology duration. Pore pressure is the pressure of fluids in the pores of a rock formation. The ability to predict the physical formation of geological structures provides significant benefit in understanding the evolution of stress and pore pressure distribution within a field and, in particular, the material state of the reservoir units. These can be used by geologists and reservoir engineers to improve understanding of hydrocarbon basins, identify potential drilling hazards and improve well positioning. Consequently, velocity determination is the key to pore pressure prediction. Pore pressure prediction is required in order to carry out safe drilling and well completion job. Pore pressure prediction has been a vital concern to the oil and gas industry for many decades. A new approach to pore pressure predictions generation. The pore pressure prediction module adds a complete workflow for interactive geopressure analysis, including prediction at wells and full 3d pressure models. The two major pore pressure prediction techniques employed are the eatons and bowers models while the eatons fracture pressure model and the hubbert and willis fracture pressure prediction models were utilized for.
Applications are presented in deepwater and subsalt wells to improve pore pressure. Pore pressure prediction using seismic velocities 1 to optimize drilling decisions and well planning in overpressured areas, it is essential to carry out pore pressure predictions before drilling. The pressure of fluids within the pores of a reservoir, usually hydrostatic pressure, or the pressure exerted by a column of water from the formations depth to sea level. Geologic pore pressure prediction an application of. However, without establishing the geological groundwork for these mathematical equations, results can be misleading. Drillworks software helps both engineering and geoscience domains better understand the subsurface environment and avoid costly delays. Challenges in pore pressure prediction for unconventional petroleum systems changrui gong.
If predrill pore pressure prediction has big uncertainty, realtime pore pressure detection is needed to update predrill pore pressure prediction and advise drilling operations in realtime. Research highlights pore pressure prediction methods are modified using depthdependent normal compaction equations. One example of analysis using a trend line is the equivalent depth method illustrated in fig. Pore pressure and fracture gradient easy mapping of trendlines to offset wells.
Topics will include methods of prewell prediction using seismic and basin modeling as well as evaluation using trend analysis techniques and pore pressure indicators. The petrophysical data were evaluated using ikons science rokdoc software. Pore pressure prediction in orthotropic medium based on rock. Pore pressure prediction pore pressure predictions and transformations that make use of seismic velocity measurements have a huge impact on drilling safety and the economics of drilling design and well construction. The realtime monitoring should ensure that 1 pore pressure is continuously monitored and indicators of the abnormal pressures are identified.
Pore pressure prediction has gradually became an integral part in the oil and gas industry as it provides the estimates for pore pressure in reservoirs or wells. Calculate dexponent to predict pore pressure trends excel. Pore pressure prediction naftagas oilfield services. Drillworks pro software provides comprehensive pore pressure and geomechanical analysis for singlewell applications. Most petroleum provinces exhibit overpressures, and as the industry explores for deeper targets, encountering high overpressures is becoming more common. Pore pressure prediction in challenging areas reducing. Calibrate pp to credible information as it becomes available. Pore pressure prediction porosity stress mechanics.
The aim of this work is to present an integrated workflow for the onedimensional 1d analysis of pore pressure pp prediction and mudweight window mww for subsalt well sections as well as. Current seismic approaches for pore pressure prediction mainly initially establish the relation between vertical effective stress and physical parameters velocity, resistivity or porosity, and then predict pore pressures with the known effective stress theory. However, its prediction an essential step of any hydrocarbon exploration and exploitation program. The pore pressure prediction module is utilised to estimate the effective stress. This method first assumes that there is a depth section over which the pore pressure is hydrostatic, and the sediments are normally compacted because of the systematic increase in effective stress with depth. Drillworks standard software puts pore pressure data and analysis tools at your fingertips. The estimates are either used by geologists or mud engineers for safety by identifying the potential drilling hazards. However, its prediction an essential step of any hydrocarbon exploration and. Velocity determination for pore pressure prediction cseg.
Martin traugott, acclaimed gom pore pressure specialist, to develop deepwaterpro, our advanced pore pressure prediction software. Influence of pore pressure on wellbore instability. The assumption that the sedimentary section above the top of geopressure i. Engineering software hxr has partnered with pegasus vertex to jointly develop erdpro, one of the industrys most advanced modular drilling engineering software suites available, and with dr. Using datasets from the gulf of mexico the course introduces some of the basic concepts of overburden calculation, pore pressure prediction and fracture pressure calculation, but is not intended to be a comprehensive. Mangaraj2, c summary the subject of detection of abnormally high pressured zones from seismic has. In order to ensure well stability and assess optimal orientation for fracture development, drilling professionals need to understand regional stress orientations and magnitudes, and how they affect rock properties in the formations around a wellbore. Therefore, accurate comparison of the alternatives is with respect to this value. Pressure porosity 3 since pore pressure prediction in shales relates porosity to e. Display of calibration data from drilling or other techlog wellbore software platform tools such as the techlog formation pressure module. Pore pressure models derived from the integration and careful calibration of traditional wireline.
The two major pore pressure prediction techniques employed are the eatons and bowers models while the eatons fracture pressure model and the hubbert and willis fracture pressure prediction models were utilized for fracture prediction. Traditional pore pressure prediction assumes that all shales are geologically young with low temperatures, are at their maximum burial depth, and have a demonstrable porosityeffective stress relationship where disequilibrium compaction is the mechanism of pressure generation. Improvement in pore pressure prediction resolution using cggs high densit y anisotropic velocity analysis advanced geostatistical techniques to derive rock properties and calibrate seismic and well velocities 3d gocad geomodelling technology for 3d estimations and predictions at new well location. The course presents pore pressure prediction concepts using the effective stress method eaton, bowers, traugott. Pore pressure prediction in orthotropic medium based on.
A new pore pressure prediction from compressional velocity and sonic transit time are proposed. Seismic pore pressure prediction ppp provides volumetric estimates of pore pressure across reservoirs, fields and even at the basin scale. Interactively predict overburden, pore, and fracture pressures. Defining the four pore pressure zones a, b, c and d using seismic velocity is a keystone for any predrilling pore pressure prediction. Impact of pore pressure on reservoir geomechanics depletion and stress changes. Analyze and model pore pressure and geomechanics to anticipate problems, reduce uncertainty, and optimize wellbore design for safer and improved drilling performance. Because seismic velocities correlate with effective pressure in the formation, sufficiently precise estimates of velocity obtained from seismic observations can be used to determine pore pressure.
However, its prediction an essential step of any hydrocarbon exploration and exploitation. Geomechanics and pore pressure prediction paradigm ltd. We include some of these definitions here for convenience. Pore pressure models derived from the integration and careful calibration of. Formation pressure analysis is, therefore, an integral part of any drilling operation. Using datasets from the gulf of mexico the course introduces some of the basic concepts of overburden calculation, pore pressure prediction and fracture pressure calculation, but is not intended to be. Hxrs deepwaterpro pore pressure prediction software is developed to use the unique method of integrating multiple seismicsonic velocity stacks to predict pore pressure along the 3d wellpath and also take into account the effect of centroid, buoyancy and formation temperature. Pore pressure prediction in tectonically active basins. The eaton exponent, used for the computation of the pore pressure can be determined using a single relation. The conventional approach is to use the normally pressured shale section to derive this nct, then apply it to the overpressured shale section to determine the pore pressure. Pore pressure prediction in tectonically active basins pore pressure prediction is important for both realtime drilling to optimize field safety conditions, and for paleomodeling to provide a framework for development of the basin and petroleum systems. A predrill estimate of pore pressure can be obtained from seismic.
A detailed description of pore pressure terminology can be found in bruce and bowers 2002, bowers 2002 and dutta 2002. The magnitude of the deviation from the normal trend line is used. Preknowledge of areas of potentially anomalous over or under pressure can help to mitigate drilling hazards and ensure that contingencies for mud weights and casing points have been considered in advance of. The basic steps in performing a conventional 1d pore pressure analysis are. Uncertainty, realtime updating and how real time updating reduces uncertainty ahead of the bit. Pore pressure analysis mainly includes three aspects, that is, predrill pore pressure prediction, realtime pore pressure detection, and postwell analysis. When impermeable rocks such as shales form as sediments are compacted, their pore fluids cannot always escape and must then support the total overlying rock column, leading to anomalously high formation pressures.
Modern modeling technologies for petroleum systems provide a complementary approach to. Drilling safe and economic deviated wells in complex reservoirs requires additional analysis and precise well planning. Pore pressure the pore pressure may also be referred to as formation pressure and is the fluid pressure within the pores of a soil or rock. A theoretical pore pressure model is proposed based on effective stressporositycompaction theory. Pore pressure prediction is critical to reducing drilling costs and exploring hydrocarbons. Feb 06, 2018 safer drilling log based pore and fracture pressure prediction. The aim of this work is to present an integrated workflow for the onedimensional 1d analysis of porepressure pp prediction and mudweight window mww for subsalt well sections as well as. The course describes the background to, and the prediction and evaluation of, overburden, pore and fracture pressures. The solution applies both industry standard and proprietary technologies in a small footprint easy to use application to predict and analyze pore pressure before, during and after drilling.1577 103 684 991 688 483 839 214 966 642 494 494 78 279 424 259 483 328 161 1517 350 1296 1029 905 862 419 570 1054 1456 198