Thomasstieber method was used to determine sand porosity and sand fraction, and water saturation was computed using pouponleveaux. Petrophysical analysis of the 3rd bone spring formation. Multicomponent induction resistivity logs allow differentiation of horizontal and vertical resistivity. There could be some sand beds which are still thinner than the resolution of the image logs. Petrophysics across the petroleum industry from a core to a ceo australian oil and gas exhibition and conference.
Bone spring formation is predominantly shaly sand with intermittently interbedded carbonate layers. Interpretation difficulties arise whenever the portions of clay minerals in a shaly sand formation are high. If these departures are unrecognized, water saturation can be overestimated, and this can result in loss of opportunity. The dominance of low resistivity layers, in laminated shaly sand formations, pose problems in the log interpretation in conventional resistivity measurements. Fesaus april 2020 talk webinar how to do quicklook shaly sand log analysis with confidence mark deakin mark deakin is a consultant and course instructor in petrophysical data integration. Subsurface and petrophysical studies of shalysand reservoir targets in apete field, niger delta. Petrophysical evaluation of shaly sand reservoirs in palougefal. Petrophysical evaluation of the upper and lower shaly gas sand reservoirs of the sahara field, using conventional well log interpretation techniques and relating the results to core data, shows. A case study from the horn river basin, canada 290 2.
Analysis of shaly sand reservoir rocks in the eastern niger delta. Worthington observed that the log analysis literature has at least thirty empirical equations for the water saturation of shaly sands. Geologic and field data background the horn river basin is located in northeast british columbia, canada, and is known to have shale gas reservoirs containing free gas and adsorbed. Waxmansmits the rollsroyce of shaly sand models alan johnson integrated petrophysical solutions ltd london petrophysical society seminar petrophysics 101 7th march 2019 why the title. I have well log data in las format and need to get porosity in %. Comparison of petrophysical characteristics of a shaly sand reservoir using shale volume and double layer models conference paper pdf available may 2017 with 1,291 reads how we. Taking the logarithm of both sides of equation 2, we get the following equation. As a result, there are more than 30 shaly sand interpretation models, which have been developed in the last 50 years. An onshore gas field hereafter called the r fieldreal name not revealed is in the southeast coast of tanzania which includes a tertiary aged shaly sand formation sand shale sequences. How to do quicklook shaly sand log analysis with confidence. Shale is composed of silt, clay and their bounded water which will not flow. The presence of clay minerals and shale laminations strongly affects the physical properties of the reservoir rock and induce significant effects on the response of most logging tools.
Petrophysical characterization using the considered shaly sand analysis models will enable a better evaluation of the reservoir quality and. Shaly sand with oil and water crains petrophysical handbook. Hydrocarbon are stored only in pore space in sand matrix. Integrated petrophysical evaluation applied to the characterization.
There is no density neutron cross over in the clean sand, so this zone is oil bearing. Evaluation of low resistivity laminated shaly sand reservoirs. Analysis of shaly sand reservoir rocks in the eastern. Crains petrophysical handbook porosity shaly sand models. Shaly sand petrophysics training course petroskills aps. Because of the important effects that shale or clay have on both reservoir quality and well log response, a working knowledge of the subject provides a. Conclusion the objective of this paper is to summarize the challenges faced during the comprehensive formation evaluation for this complex shaly sand reservoir. Shaly sands see also shaly sands with confidence in a petrophysical sense shaly sands are clastic rocks with excess conductivity, that is a conductivity greater than the free water conductivity treated by the archies equation. Patnode and wyllie claimed that the conductivity of the clays in a shaly sand is a constant which is independent of the conductivity of the brine saturating the pore spaces of the rock, cw. A series of systematic calculations were performed in both software programs microsoft excel 20 and techlog by schlumberger 20. Pdf subsurface and petrophysical studies of shalysand.
Deterministic pore pressure estimation for shaly sand. This study presents an integrated petrophysical evaluation for nahr umr reservoir by highlighting a practical trustworthy approach petrophysical model for nahr umr reservoir in subba oil field depending on available data. The laminar shale portion of the rock shows the volumes of dry laminar shale and its associated bound water. Shaly sand interpretation using cecdependent petrophysical. Geometric properties of shaly sand rock samples used in the. Hewlettpackard, 1984, model 4276a lcz meteroperation and service manual. Print to pdf email progression map browse sessions in this. For a shale layer, r t in equation 3 will be equal to r sh. Petrophysical interpretation in shaly sand formation of a. If 10% shale is added to the sand, then the point will plot in slightly different. Petrophysical interpretation compute shale volumes, porosity and saturation i. Core data listing for shaly sand example but see next illustration the average porosity is 25. Great appreciation is extended to faisal al adwani for all of his technical discussion and assistance.
Development and field applications of shaly sand petrophysical models a dissertation submitted to the graduate faculty of the louisiana state university and agricultural and mechanical college in partial fulfillment of the requirements for the degree of doctor of philosophy in the department of petroleum engineering by milton n. The porosity is higher than the log analysis shown earlier and the log results could be made to match the core by reducing shale volume or shifting the density porosity to a higher value. The clean waterbearing sand has an effective porosity of 30%, and is given by point sd on the densityneutron crossplot fig. Shales in the reservoir causes complications for the petrophysicist.
Integrated petrophysical evaluation applied to the. A tsh decreases with v sh while b tsh is increases with the v sh. The interpretation of shaly sands log data has long been a challenge. Reservoir rock, shaly sands, petrophysical parameters, well. Integrated petrophysical evaluation applied to the characterization of shaly sand reservoirs in the santonian. This paper presents the main results obtained from the treatment of unconsolidated sands in such shaly sand formations. The formation was penetrated by an exploration well rx wherein no core was acquired, and there is no layerwise published data of the petrophysical properties of the r field. As majority of the response is due to the shales, the sand layers consisting of hydrocarbon will have little effect on the overall. Petrophysical approach for estimating porosity, clay volume, and water saturation in gasbearing shale.
Improved workflow for evaluation of thinly bedded sandstones. Rather than using porosityconductivity log analysis a tool intrinsically unsuited to the task at hand this paper sets out simple, crossdisciplinary techniques which crosscheck and harden quicklook log analysis. The following definition and petrophysics model are a typical shaly sand formation model which assumes. An integrated formation evaluation approach for maximizing. Petrophysical evaluation, shaly sand reservoirs, density neutron logging, palougefal oil. Some studies were carried out regarding petrophysical analyses of shaly sand reservoir of bengal basin, bangladesh 2 345.
Laminated shaly sand reservoirs an interpretation model. For a clean formation b tsh becomes zero and a tsh becomes unit. Purchase of an open document does not constitute license for republication in any form, nor does it allow web posting without prior written permission. Petrophysical interpretation in shaly sand formation of a gas field in. Vsh rsh from log analysis indonesia eqn formulated for evaluation of shaly sands with low salinity formation water.
The measurements of porosity, permeability, electrical properties and mineralogy made on. Petrophysical evaluation of shaly sand reservoirs in. Research article subsurface and petrophysical studies of. Wireline logs of four 4 wells from apete field were studied to delineate petrophysical. Pdf petrophysical analysis in reservoir characterization. The volumetric petrophysical model used in this work for a laminated shaly sand formation is depicted in figure 1, with the main rock components being laminar shale and sandstone.
It was observed that, shale correction leads to a significant change in petrophysical parameters. As far i know, porosity can be calculated from each of these parameters, being generally. Petrophysical techniques and tools developed with demand from the industry. Petrophysical models and techniques for shalysand formation. We cannot tell about the upper shaly sand because the shale effect masks any. Petrophysical approach for estimating porosity, clay. Comparison of petrophysical characteristics of a shaly. The results obtained indicate that, the simandoux and indonesian models used for the study are both suitable for water saturation, and hydrocarbon saturation analysis in shaly sands of this part of the basin.
Integrated petrophysical evaluation applied to the characterization of shaly sand reservoirs in the santonian gas field, santos basin, brasil. Petrophysics across the petroleum industry from a core to. The archie equation treats all rock conductivity as being due its free water so when cw0 then whole rock conductivity. This course tackles the important and nontrivial problem of practical formation evaluation in shaly sand provinces. Petrophysical evaluation of shaly sand reservoirs in palougefal oilfield, melut basin, south east of sudan rashid a.
On the other hand, shalysand formations have shale and clay present in. Pdf comparison of petrophysical characteristics of a shaly sand. Pdf petrophysical analysis plays an important role in a reservoir study as it provides primary input data in volumetric calculation. Crains petrophysical handbook shaly sand with oil and water. A full welllog suite including geochemical data was presented in the assignment for analysis. Comparison of petrophysical characteristics of a shaly sand reservoir using shale volume and double layer models conference paper pdf available may 2017 with 1,291 reads how we measure reads.
Shaly sand analysis for total porosity systems using waxman smits equation. Conventional departures from archie conditions for petrophysical attribute delineation include shaliness, fresh formation waters, thinbed reservoirs, and combinations of these cases. Journal of petroleum exploration and production technology 2020 10. Introduction to tools and techniques image logs, nmr, geochemical logs, petrography. Services and skills petrophysics deeringpetrophysical. Advanced petrophysics 06th april 2015 10th april 2015, kuala lumpur, malaysia the basis of the e. Pdf petrophysical analysis of shaly sand gas reservoir.
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