Subsequently, various stressvelocity relationships predict pore pressure, which are refined to calibration data such as mud weight, pressure measurements and drilling events. Current commonly used methods of pore pressure prediction are based on the difference between a normal trend in sonic wave velocity, formation resistivity factor frf, or dexponent a function. Pore pressure prediction is a method of forecasting by using data that provides information about upcoming events or risks beforehand. Antenatal blood pressure for prediction of preeclampsia, preterm birth, and small for gestational age babies.
Surge pressure prediction for running liners 4 closed pipe fully open autofill with flow diverter fig. Calibrate pp to credible information as it becomes available. General m,odel for prediction of pressure drop and capacity of countercurrent gasliquid packed columns j. 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.
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. Pdf prediction of pore pressure and fracture pressure in. A new equation of pore pressure prediction strategy based. If it is not properly evaluated, it can lead to numerous drilling problems such as dangerous well kicks, lost circulation, blowouts, stuck pipe, excessive costs, and borehole. This paper will not focus on pore pressure prediction but on realtime detection. Rock physics of geopressure and prediction of abnormal pore. The role of pore pressure prediction in reservoir exploitation basic principles of pore pressure systems pore. White paper surge pressure prediction for running liners. Pdf pore pressure prediction using geophysical methods in. Pore pressure prediction naftagas oilfield services. Display of calibration data from drilling or other techlog wellbore software platform tools such as the techlog formation pressure module. Different methods for pore pressure prediction have been proposed based on resistivity, sonic transit time or interval velocity, and other petrophysical data e. Pore, abnormal formation and fracture pressure prediction.
Two models were used each for predicting pore pressure and the corresponding fracture pressure using well. Pore pressure prediction in unconventional resources onepetro. The pore pressure prediction module is utilised to estimate the effective stress. State key laboratory of petroleum resources and prospecting, china university of petroleumbeijing. Pore pressure calculation methods dug insight user manual.
The relation between effective pressure and velocity depends heavily on the texture and mineral composition of the rock. Experience from several unconventional plays highlights key aspects of pore pressure prediction work that are different from conventional exploration settings. The geologic structure interpretation provided by the customer will be used to estimate the potential for centroid and buoyancy effects. Pore pressure prediction using seismic velocity modeling.
Pore pressure models derived from the integration and careful calibration of traditional wireline. A quantitative predrill prediction of pore pressure is required when drilling in overpressured formations, and can be obtained. Generally, it offers the knowledge of the pore pressure while drilling the deep water wells. Todays topics ppp technology overview suitforpurpose seismic velocity analysis a workflow example ppp in 1d and 3d. Shale sections are best for analysis of logs for abnormal pore pressure. Largescale pore pressure prediction after prestack depth. During the exploration phase, knowledge of the spatial distribution of formation pressures can be used to develop fluid migration models, to study.
Pore pressure prediction overpressure causes and detection. Participants learn a variety of pore pressure calculation methodologies. Methodology used to derive the overburden gradient key parameter of terzaghi equation different. Practical exercises build expertise in handling the data used to make pore pressure predictions. The sandclay acoustic model for shaley sandstones, developed by carcione et al. No wonder there abound several methods for its prediction. It is useful because it enables drilling to continue without any delays or incidents. Apart from some uncertainty in porefluid density, this provides a simple prediction of the pore pressure i. Pore pressure prediction porosity stress mechanics. Figure 23 shows the result of transforming the velocities in figure 22 into pore pressure gradient in equivalent density units. Equations are given for use with resistivity plots, conductivity plots, sonic traveltime plots, and corrected d exponent plots. Pore pressure estimation is important for both exploration and drilling projects. Pdf abnormal pore pressure can cause some problems during the drilling process such as a blowout or sticking pipe while drilling.
However, it is now recommended by the water losses task force thornton 2003. Pdf origin of overpressure and porepressure prediction. This is a continutation of rock physics of geopressure and prediction of abnormal pore fluid pressures using seismic data part 1 4. Comparing methods of predicting pore pressure ijser. Muhammad adam bin mahadzira nguyen xuan huyb a affiliation for first. Because of their low permeabilities, shales do not equilibrate pressure with the mud column in the well bore. Changes in pore pressure can be recognized on regular formation eval uation tools such as sonic, resistivity, porosity, and density logs. Seismic driven pore pressure prediction joanne wang. Pdf integrated approach to pore pressure and fracture.
Methodology used to derive the overburden gradient key parameter of terzaghi equation different techniques can be used according to well data available. Geoscientific data from several wells drilled in onshore and offshore parts of the cauvery and krishnagodavari basins, two main hydrocarbon producing basins located in the east coast of india, have been used to determine pore pressures and fracture. Pdf pore pressure prediction using velocitybased methods. Pore pressure prediction formation pressure analysis is, therefore, an integral part of any drilling operation. An effective basin model concept is introduced as a well balanced combination of classical engineering and basin modeling approaches to the problem of pore pressure prediction before and during drilling.
During the exploration phase, a prediction of pore pressure can. Pore pressure prediction ppp, when done accurately can be used to avert disaster and helps in safe drilling. Pdf pore pressure prediction in a carbonate reservoir. Current commonly used methods of pore pressure prediction are based on the difference between a normal trend in sonic. 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. Farkha petroleum engineering department, koya university, iraq abstract oil and gas well drilling planning is the main task of any drilling engineer. The most common methods of predict ing pore pressure in the industry were compared in this study. Therefore, accurate comparison of the alternatives is with respect to this value. Pdf reliable prediction of pore pressure pp is critically important to petroleum engineering at different stages. Origin of overpressure and pore pressure prediction in the.
Understanding pore pressure prediction in unconventional plays is important for executing a safe drilling strategy and for accurate production modeling. Seismic pore pressure prediction in the norwegian sea. Pore pressure prediction and modeling using seismic velocities. A predrill estimate of pore pressure can be obtained from seismic. Resistivity, sonic, and density logs as well as some others can give clues to the presence of over or underpressure. Pore pressure prediction and modeling using welllogging data in one of gas fields in south of iran article in journal of petroleum science and engineering 128 april 2015 with 655 reads. Pdf pore pressure prediction using eaton and neural network. The subsurface hydrogeological zoning greatly impacts the velocity, resistivity and density profiles. Seismic pore pressure prediction methods of evaluating abnormal pore pressures are separated in two categories, prediction methods and detection methods.
The resulting section demonstrates the level of detail that can be derived in pressure prediction using residual velocities. Does the use of the pressure sore prediction score. Abnormal high formation pressure prediction and causes analysis. If the variables are limited weight on bit, rotary speed, mud properties, pump pressure, and bit type, the major remaining variable that affects rate of penetration in shale is porosity. A comparative model approach to pore pressure prediction. All methods take advantage of the fact that sonic velocities depend on the effective pressure, and hence the pore pressure. Using interval velocity volume to estimate pre drill porepressure. In order to overcome this task, it is required to maintain the wellbore pressure between the. Prediction of pore pressure and fracture pressure in cauvery and krishnagodavari basins, india article pdf available in marine and petroleum geology 78. Pdf pore pressure prediction using wellconditioned. A normal pressure is defined in rejation to the depth at which it is encountered.
Pore pressure calculation in a hydraulicallyconnected formation is introduced. Porepressure and fracturegradient predictions onepetro. 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. Extensive experience on workover, completion logging interpretation and design. Changes in pore pressure can be recognized on regular formation evaluation tools such as sonic, resistivity, porosity, and density logs. Pore pressure prediction from well logs and seismic data. The figure also demonstrates a pitfall of pressure prediction where hydrocarbons are present. Pipe end conditions closed pipe as pipe is moved downward into a well, the original mud is displaced by the new volume of the extending pipe and the mud must move upward. 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.
A pressure that is normal for a specific depth would be abnormally high for a shallower depth. View a new equation of pore pressure prediction strategy based on eaton model paper tm. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Pore pressure prediction free download as powerpoint presentation. The pressure at the bottom of the structure will be equivalent to. Prediction of pressure characteristics in settling chamber of 0. Formation sedimentary environment change will cause high pressure, and the properties of formation will change accordingly. When unexpected porefilling calcite is seen, a pressure seal should be considered a possibility. These logs show the effects of pore pressure because of the relationship between compaction, porosity, density. Longterm blood pressure prediction with deep recurrent neural networks peng su, xiaorong ding, yuanting zhang, fellow, ieee, jing liu, fen miao, ni zhao abstractexisting methods for arterial blood pressure bp estimation directly map the input physiological signals to output bp values without explicitly modeling the underlying temporal. Pore pressure prediction from well logs and seismic data resulted in the development of four equations that may be used for the prediction of geopressure from well logs and drilling data. Pore pressure prediction using wellconditioned seismic velocities.
Pressure prediction methods drilling engineering netwas. Provides pore pressure and fracture gradient ppfg predictions for the planned wells based on log data and pressure measurements from two 2 offset wells along with extracted seismic velocity traces at the offset and planned well locations. These pressures cannot be detected with conventional techniques. Using this theoretical model, pore pressure prediction from porosity and compressional velocity sonic transit time have been obtained. Pore pressure prediction is used to develop a 3d model for the pressure regime and it is a critical property towards an effective reservoir simulation and management. Theoretical pore pressure porosity model is the fundamental for pore pressure prediction in shales, where the compaction disequilibrium is the primary mechanism of overpressure generation. Fair university of essen, 4300 essen 1, frg separations research program, university of texas at austin, austin, tx 78712, usa received 24 october 1988. Any unusual porefilling minerals seen in cutting samples should alert the geologist to the potential of a pressure seal.
Origin of overpressure and pore pressure prediction in the baram province, brunei article pdf available in aapg bulletin 931. This 2day course provides the participants with strategies for making pore pressure predictions. Velocity determination for pore pressure prediction cseg. Detection methods traditionally use drilling parameters and well log information. Pdf pore pressures in most deep sedimentary formations are not hydrostatic. Pore pressure prediction and modeling using welllogging. When the indicator suggests porosity values that are higher than the trend, then abnormal pressures are suspected to be present. Longterm blood pressure prediction with deep recurrent. In order to overcome this task, it is required to maintain the wellbore pressure.
Predrill pore pressure prediction using seismic velocities data on flank and synclinal part of atharamura anticline in the eastern tripura, india, journal of petroleum exploration and production technology, 20, pp. Challenges in pore pressure prediction for unconventional petroleum systems changrui gong. However, a number of different compaction trends can be. Predrill prediction of formation pore pressure from surface seismic survey is very important for drilling, production, and reservoir engineering because it affects drilling operations and wellplanning processes.
Prediction of pressure characteristics in settling chamber of. This study investigated the cause of identified zones of overpressure in some selected wells in a field in the niger delta sedimentary basin. General m,odel for prediction of pressure drop and capacity. Mitchell 2004 concludes that the pressure sore prediction score is an. Drilling time is useful for detecting abnormal pressure. Pore pressure prediction reduce uncertainty in pore pressure estimations. Razak damit5 1 australian school of petroleum, adelaide, australia 2 deeppp exploration technologg,ies crc, adelaide, australia. The prediction methods normally use data obtained from seismic surveys, offset well logs and well history.
Pore, abnormal formation and fracture pressure prediction f. Jun 14, 2017 predrill prediction of formation pore pressure from surface seismic survey is very important for drilling, production, and reservoir engineering because it affects drilling operations and wellplanning processes. Case histories from the gulf of mexico selim simon shaker, geopressure analysis services, houston, tx coordinated by rob holt a comprehensive framework and fresh perspective to pore pressure predic tion methods and algorithms based on the. When the pipe is closed or contains a float sub, all. It is one of the most important services provided by ml services, but is almost one of the, technically, most demanding. Until this time, the pore pressure in this region has only been determined for new wells before drilling activity. A predrill estimate of formation pore pressure is a key requirement for successful exploration and drilling. Pore pressure is the pressure of fluids in the pores of a rock formation.
Pdf integrated 1d workflow for porepressure prediction. A global algorithm for pore pressure prediction delta geophysics. Antenatal blood pressure for prediction of preeclampsia. Seismic pore pressure prediction in the norwegian sea, halten terrace the halten terrace the study area is highlighted in green covering the halten terrace in the norwegian sea. A problem arises, however, and this is the feature of this article, that existing techniques for pore pressure prediction that were developed for shales are being applied to these targets with little consistency. Challenges in pore pressure prediction for unconventional. Pore pressure prediction is required in order to carry out safe drilling and well completion job. Pore pressure predictionpore pressure prediction improve your techniques and learn from the expert. These techniques rely on remote detection of porosity anomalies and using seismic andor log data.
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