Shale gas characterization and property determination by. Pdf rock physics modeling for shale gas identification sonny. Challenges associated with shale gas reservoir exploration increase the importance of applying elastic parameters or velocity at the logging scale. Natural gas is found in rock formations reservoirs beneath the earths surface.
Rock physics modeling in montney tight gas play cseg. Unconventional shale reservoirs differ largely from conventional sandstone and carbonate reservoirs in their origin, geologic evolution and current occurrence. Xuan qin, dehua han, and luanxiao zhao, rock physics lab, university of houston. Estimation of anisotropy parameters for shale based on an. Application of rock physics to an exploration play.
So it might seem intuitive that refracturing the tens of thousands of existing fracked wells could unleash a second boom at comparatively low cost and with. Shale is a wide variety of rocks that are composed of extremely finegrained particles. Pdf rock physics modeling for shale gas identification. November 2017 physics today27 h ydrofracturing, or fracking, has been extremely e. Comprehensive and uptodate, fundamentals of gas shale reservoirs is an essential reference for anyone interested in gas shale reservoirs. Focus 1 rock physics modeling in montney tight gas play ayato kato1, kunio akihisa1, carl wang2 and reona masui3. A rock physics model of kerogen inclusions in shale qi hu1,2, xiaohong chen1,2 and yi guo1,2 1 state key laboratory of petroleum resource and prospecting china university of petroleum, beijing, china 2 cnpc key laboratory of geophysical prospecting, china university of petroleum, beijing, china summary development of a shale gas rock physics model is extremely difficult because organicrich. Rockphysics templates forhydrocarbon sourcerocks short title. As a result, resolving petroleum and gas reservoir properties in. In this study, we develop rock physics models to simulate the elastic properties of organicrich shales with different maturity levels.
Unconventional resources such as shale gas are becoming increasingly important exploration, development, and production targets. A rock physics modelling algorithm for simulating the. Rockphysics modeling for the elastic properties of. We will first discuss rock physics relationships from this well and then simulate seismic and em responses. As an unconventional resource, shale gas has recently received. Because of the heterogeneity and anisotropy, seismic reservoir characterization for shales is challenging. Applied geophysics department of applied geophysics, indian school of mines, dhanbad summary rock physics templates rpts are geologically constrained rock physics models that serve as tools for lithology and fluid. Formation evaluation of an unconventional shale reservoir. Mechanical properties of shale gas reservoir rocks and its relation to the insitu stress variation. A model for estimating the effective anisotropic properties of cemented shales is presented. We introduce the clay lamination cl parameter to the backus averaging method to describe the intrinsic shale anisotropy induced by the alignment of clay minerals. A rock physics model of kerogen inclusions in shale. Seismic rock physics characterization of anisotropic shale.
Then, we perform the inversion of cl and the thomsen anisotropy parameters. Estimation of anisotropy parameters for shale based on an improved rock physics model, part 1. Discriminating gas bearing sands from shale using rock physics. Rock physics template rpt analysis of well logs for. Optimization of shale resource development using reduced. Shear wave velocity vs is essential for determining the elastic properties of rocks, which are useful for shale gas reservoir characterization. The wolfcamp shale formation in the permian basin of west texas is a complete reservoir system of source, seal and reservoir. Rock physics modeling to quantify geophysical characteristics of shale gas in lower cretaceous southern indus basin pakistan. Rock physics modeling for the elastic properties of organic shale at different maturity stages luanxiao zhao 1, xuan qin 2, dehua han, jianhua geng, zhifang yang 3, and hong cao abstract modeling the elastic properties of organic shale has been of longstanding interest for source rocks and unconventional reservoir characterization. Pore pressure prediction in orthotropic medium based on. Unconventional reservoirs are typically very complex to model, and rock physics provides insight into this complexity.
Elastic properties of the constituents and oil, gas, and water. Stanford rock physics laboratory shale lab data are sparse, compared with sandstone and. It is also a must have text for students, of any discipline, studying nonconventional oil and gas resources and it is bound to become the gold standard textbook in this field. Discriminating gas bearing sands from shale using rock physics guided inversion ahmed w. Alghamdi safouh koronfol moustafa r dernaika joel walls. Rock physics modelling of shale diagenesis petroleum. Sayers 20b calculated the effect of kerogen on anisotropy of shales. Oil and gas can be generated in kerogen rich shales at the oil. We present data on the general mechanical behavior of these rocks, the staticdynamic elastic properties, and anisotropy to delineate the basic parameters that control gas shale mechanical properties. Li british geological survey summary rock brittleness plays a significant role in effective hydraulic fracturing for shale gas. They found that the mineral composition and interaction among minerals affected. This model, furthermore, can provide a tool to somehow extend passey method into seismic cubes. Rock physics templates for analysis of brittleness index. In other words, shale readily breaks into thin layers.
Mechanical properties of shalegas reservoir rocks part. Journal of natural gas science and engineering vol 74. Shale gas has become an increasingly important source of natural gas in the united states since the start of this century, and interest has spread to potential gas shales in the rest of the world. Rock physics, along with the inverted seismic data, can be used to detect the presence of hydrocarbon bearing rocks and forecast their. A study on refining shale oil and gas refining chemical. We have developed an improved anisotropic rock physics model to incorporate toc effects, in addition to effects of mineralogy, porosity, and fluid content, on seismic and electrical properties of shale gas. Application to the north slope alaska a report submitted to the department of energy resource engineering of stanford university in partial fulfillment of the requirements for the degree of master of science in petroleum engineering by minh tuan tran june 2014. The shale is composed of quartz, clay, carbonate, the mixture of kerogen and hydrocarbons, and. The preferred orientation of clay minerals dominates the intrinsic anisotropy of shale. Black and gray shale are common, but the rock can occur in any color. A rock physics modelling algorithm for simulating the elastic.
Rock physics templates for analysis of brittleness index, mineralogy, and porosity a barnett shale case study z. Improved rockphysics model for shale gas reservoirs. Fundamentals of gas shale reservoirs wiley online books. Due to the huge differences between the unconventional shale and conventional sand reservoirs in many aspects such as the types and the characteristics of minerals, matrix pores and fluids, the construction of shale rock physics model is significant for the exploration and development of shale reservoirs. Rock physics model of the eagle ford shale onepetro. An evaluation of empirical and rock physics models to estimate. Pore pressure prediction in orthotropic medium based on rock physics modeling of shale gas. The defining characteristic of shale is its fissility. Anisotropy rock physics model for the longmaxi shale gas. This includes matrix ow and ow through fractures of various sizes, gas.
A rock physics model for the characterization of organicrich shale. Shale gas characterization and property determination by digital rock physics. Shale gas is natural gas that is found trapped within shale formations. Proceedings hagiiagi joint convention medan 20 28 31 october rock physics modelling for shale gas identification muhammad saladin islami1 and. Shale rocks contain a waxy substance, kerogen which when intensely heated liquefies to produce a precursor to crude oil. A deeper understanding of rock physics is necessary for successful exploration and production. Unlike conventional plays, shale plays have very low permeability and are both the trap and seal. Rock physics of the unconventional colorado school of mines. Shale gas characterization and property determination by digital rock physics august 2015 anas almarzooq tariq m. Pdf our study applied a geophysical well log analysis, rock physics diagnostics and rock physics modelling to an exploration well log data. Rock physics templates rpt establish a link between the elastic properties e. Bakken shale has class iv avo and its amplitude is affected by kerogen maturity. Primer on rock physics finding transforms and applying them to impedance inversion reflection amplitude carries information about elastic contrast in the subsurface. Rock physics integrating petrophysical, geomechanical.
Permeability refers to the capacity of a porous, sediment, soil or rock in this case to transmit a fluid. Mechanical properties of shale gas reservoir rocks and its relation to the instu stress variation observed in shale gas reservoirs. The proposed geology guided rock physics model enables us to find a relationship between kerogen maturity and pwave velocity from sonic logs. Zhu et al used rock physics relationships and seismic modeling to understand the geophysical responses of shale gas plays at both well log and seismic scales. Muhammad haroon afzal1, hassan1, nisar ahmad1, shahid ghazi1, and perveiz khalid1. To make a better characterization of shale gas bearing reservoirs, we first propose a new. Rock physics of shales and source rocks gary mavko professor of geophysics director, stanford rock physics project. Rock physics is a key component in oil and gas exploration, development, and production.
In this paper, we present rock physics modeling in montney tigh gas play. Rock physics template rpt analysis of well logs for lithology and fluid classification nabajyoti boruah final year, m. An anisotropic rock physics model based on effective medium theories is constructed for shales and applied to the longmaxi shale formation. Rock physics modeling for shale gas identification. Natural gas and petroleum may be extracted from oil shale. Rock physics modeling of organicrich shales with different maturity levels. Pdf shale gas characterization and property determination by. Pdf rock physics diagnostics and modeling for shale gas. Shale gas formations are unconventional reservoirs i. The direct measurement of anisotropy is difficult because of the.
Rock physics model of the eagle ford shale authors colin m. A shale rock physics model and its application in the prediction of brittleness index, mineralogy, and porosity of the barnett shale zhiqi guo1, 2, mark chapman3 and xiangyang li1 1british geological survey, 2jilin university, 3the university of edinburgh summary defined in terms of mineralogy or. The key contributions of this dissertation are 1 incorporation of parameter uncertainties into existing models that are used for estimating petrophysical properties of subresolution sand shale systems, 2 a new method for approximating fluid substitution in thinly bedded sand shale. A rock physics based petroleum reservoir characterization.
A shale rock physics model and its application in the. Director of the stanford rock physics laboratory andprofessor of geophysics phone. Rock physics integrating petrophysical, geomechanical, and seismic measurements. April 1, 2020 effective seismic reservoir characterization, a rock physics approach. Main question of rock physics how to remotely map rock properties and conditions. Rockphysics templates for hydrocarbon source rocks purdue math. Geophysical model response in a shale gas flooding surfaces highlights the richest organic zones younes et al. Our study applied a geophysical well log analysis, rock physics diagnostics and rock physics modelling to an exploration well log data from a shale gas exploration area in the sichuan basin of. The model is based on two mathematical methods for estimation of effective properties of a composite medium. A rock physics model for the characterization of organic. In the rock physics model, intrinsic vti transverse isotropy with a vertical asymmetry axis anisotropy due to preferred orientations of clay particles is quantified by introducing the clay lamination cl. Pwave velocity is inverted from azimuthal seismic data based on the reflectivity approximation of oa medium. In combination these theories allow approximation of a shale with connected clay minerals and cement. Rock physics diagnostics and modeling for shale gas formation characterization in china gang yu 1, yusheng zhang 1, paola newton 2, and ilgar azizov 2,3, 1 bgp inc.
A proper rock physics model can help effectively study the rock characteristics. It is used to make brick, pottery, tile, and portland cement. The haynesville shale reservoir is also overpressured parker et al. Rock properties for success in shales ted holden, john pendrel, fred jenson, and peter mesdag. This webinar from ikon science focuses on the practical use of powerful seismic reservoir characterization techniques to enhance our understanding of both subsurface architecture and petrophysical properties, within pragmatic timeframes. Discriminating gas bearing sands from shale using rock. Pdf unconventional shale reservoirs differ largely from conventional sandstone and. Mechanical properties of shale gas reservoir rocks and its. The rock physics modeling of shale gas in orthotropic oa medium is designed to equate the normal compaction trend nct to predict pore pressures. A case study from the brazeau river 3d heath pelletier, jay gunderson, veritasdgc, calgary introduction the ultimate goal of any rock physics analysis is to gain insights into the physical properties of a reservoir.682 875 538 1113 1389 815 978 959 1297 275 66 80 1529 144 1005 789 791 75 204 1349 102 549 574 176 707 513 936 1087 133 1282 500 1360 944 56 317 412 543 1385 328 981 1076 553