共查询到20条相似文献，搜索用时 431 毫秒
1.
Okechukwu E. Agbasi Magnus U. Igboekwe Godwill U. Chukwu Etuk E. Sunday 《Arabian Journal of Geosciences》2018,11(11):274
Quantitative rock physics analyses were used to determine the lithology and pore fluid of a reservoir in the Niger Delta. Inaccurate prediction of lithology and pore fluid results in the inaccurate determination of other petrophysical properties and parameters such as porosity, permeability, and net pay. This research is to predict lithology and pore fluid using rock physics analysis. However, reservoir zones were also predicted. Density, compressional wave velocity, and shear wave velocity logs were used as input to calculate elastic parameters such as velocity ratio, Poisson’s ratio, and bulk modulus. The calculated velocity ratio log was used to differentiate between sand and shale. Poisson’s ratio and velocity ratio using Goodway interpretation template were carried out and used to delineate pore fluid content, gas sand, oil sand, and sandstone formation from crossplot analysis. 相似文献
2.
针对伊通盆地鹿乡断陷五星构造带油藏,提出一种适用于本区块的测井岩性识别模式及确定储层有效厚度的方法。利用包括自然伽马(吉林伽马)、普通电阻率、声波时差和自然电位曲线的综合分析,通过绘制各类曲线交会图,确定各类岩性的有效指标范围,确认出本区可识别的6种岩石类型即泥岩、粉砂岩、细砂岩、中砂岩、粗砂岩和砂砾岩。在测井解释近似的情况下,提出反推排除法,结合区域整体沉积相带分布规律和相邻井之间的测井曲线相互关系,区分细砂岩与含砾砂岩。在测井解释的基础上进行储层有效厚度研究,建立孔隙度、渗透率、含油饱和度模型,总结出岩性下限标准、物性下限标准、电性下限标准,利用建立的模型及解释图版,对本区块的39口井进行油水层校正,编制单砂层有效厚度图和单砂层岩性-微相图。 相似文献
3.
《China Geology》2022,5(3):393-401
This study focused on the quantitative analysis of the petrophysical parameters in characterizing the reservoir properties of the Srikail gas field using multi-scale wireline logs. Petrophysical parameters (shale volume, porosity, water saturation and hydrocarbon saturation) were estimated from the combination of gamma ray log, resistivity log, density log and neutron log for three hydrocarbon (gas)-bearing zones at well#3. At the first time, log records at 0.1 m and 0.2 m intervals were read for this study. Result showed the average shale volume is 21.07%, 53.67% and 51.71% for zone-1, zone-2 and zone-3, respectively. For these zones, the estimated average porosity was 35.89%, 29.83% and 28.76%, respectively. The average water saturation of 31.54%, 16.83% and 23.39% and average hydrocarbon saturation of 68.46%, 83.17% and 76.61% were calculated for zone-1, zone-2 and zone-3, respectively. Thus zone-2 is regarded the most productive zone of well#3. It was found that the values of some parameters (porosity, hydrocarbon saturation and permeability) are higher than the existing results. Therefore, this study confirmed that the log reading at minute/close interval provides better quantitive values of the reservoir’s petrophysical properties. It is expected that this result will contribute to the national gas field development program in future.©2022 China Geology Editorial Office. 相似文献
4.
Tertiary reservoir represented by Jeribe, Anah, Azkand, and Azkand/Ibrahim formations has been studied from reservoir characterization point of view in Khabbaz Oil Field/Northern Iraq. Examined thin sections prepared from core rock samples which are selected from the wells Kz-8 and Kz-9 revealed the existence of different microfacies in which are varies types of porosity such as interparticle, intraparticle, moldic, vuggy, and fractures have been noticed. In addition to these different types of diagenetic features are represented mainly by cementation, dolomitization, recrystallization, and dissolution. The available log data for the wells Kz-11, Kz-14, and Kz-16 have been used in characterizing the reservoir properties of the studied formations. The detected lithologies from porosity logs showed domination of limestone, dolomitic limestone, and dolomites in addition to few thin beds of anhydrites in Jeribe Formation and thin beds of sand dominated lithologies in Azkand Formation. Clay content has been calculated from gamma ray log along the studied sections and appeared to be mostly of dispersed clay type as shown from density-neutron porosity crossplot of Thomas-Stieber. Correction from the effect of clay content has been done for all the measured sonic, density, and neutron porosities. The available porosity and permeability values which are measured from core tests in the well Kz-9 for the formations of Jeribe, Anah, and Azkand have been adapted to formalize the best equation for calculating permeability in the other studied wells which have no core test measurements but only log data (Kz-11, Kz-14, and Kz-16 wells). Depending on porosity, permeability, and shale content, the studied sections have been subdivided into seven reservoir units in the wells Kz-11 and Kz-16, and for eight reservoir units in the well Kz-14. 相似文献
5.
Baisakhi Das Rima Chatterjee Dip Kumar Singha Rajan Kumar 《Journal of the Geological Society of India》2017,90(1):32-40
Seismic attributes such as: amplitude envelope, instantaneous phase and cosine of instantaneous phase of 2D post-stack seismic data facilitates structural and stratigraphic interpretation of shallow marine offshore, Krishna-Godavari basin. Two seismic sections namely, X and Y oriented N-S passing through wells W-1 andW-2 respectively are considered for seismic attribute analysis and porosity prediction. The gamma ray log trend indicates deposition of cleaning upward sediment. Coarsening upward, clayey-silty-sandy bodies, making a series of about 50-60 m thickness, have been evidenced from the gamma ray log. An extensional structural style comprising growth faults is associated with the progradational style of deposition. Four seismic zones have been distinguished. These zones differ in amplitude, frequency and continuity of the reflectors. Channel sands of Cretaceous age of Raghavapuram shale are identified in well log, seismic section and its acoustic impedance section. Major stratigraphic horizons along with faults extending to basement are marked with the help of attribute analysis. Porosity is mapped from transformation of acoustic impedance. The shales/unconsolidated sediments measure a high porosity with low impedance and the more porous sands are in an intermediate range. The predicted impedance and porosity values may be erroneous beyond the drilled depth because of non availability of well log data for calibration. 相似文献
6.
7.
以鄂尔多斯东缘A区块为例,通过岩石物理正演分析,论证了储层岩石物理参数的敏感性,确定利用纵波阻抗与纵横波速度比参数进行储层的识别。在此基础上进行正演模拟,研究了地震的极限分辨率及不同厚度砂体的地震响应特征,确定了运用叠前地质统计学反演为核心的储层预测技术对该研究区太原组进行储层预测研究,以解决该区储层薄、横向变化快、单一岩石物理参数无法区分岩性等问题。地质统计学反演结果表明,该方法能有效的预测厚度大于3 m的储层。对比研究区内11口测井解释厚度与储层反演厚度表明,储层反演预测厚度平均误差为7.5%,其中5口盲井的平均误差为10.2%,一口新钻井的砂体厚度预测误差为1.73%,为该区的井位部署提供了可靠的资料参考。 相似文献
8.
Identification with accuracy of prospective and dry zone from well log data is of prime importance in reservoir or hydrocarbon studies. This issue has greater stake, where in return many conventional methods have been established. The purpose of this study is to recognize the hydrocarbon and non-hydrocarbon bearing portion within a reservoir by using a non-conventional technique. Application of rescaled range (R/S) analysis and wavelet-based fractal analysis (WBFA) on the wire-line log data to obtain the pre-defined hydrocarbon (HC) and non-hydrocarbon (NHC) zones by their fractal nature is demonstrated in this paper. Among these two techniques, the WBFA tool has provided more prolific results. Applicability of the proposed approach is tested with the help of the most commonly used well log data like self-potential, gamma ray, and porosity log responses. These are used in the industry to distinguish several HC and NHC zones of all wells in the study region belonging to the Upper Assam Basin, India. The results are found to be of lower fractal dimension in this study for a particular log response having HC-bearing zones, which are mainly situated in a variety of sandstone lithology. On the other hand, NHC-bearing zones correspond to lithology with higher shale content categorized with higher fractal dimension. Hence, the WBFA technique can overcome the chance of misinterpretation, which is quite possible in the case of conventional reservoir characterization. 相似文献
9.
Factor analysis of borehole logs for evaluating formation shaliness: a hydrogeophysical application for groundwater studies 总被引：1，自引：1，他引：0
The calculation of groundwater reserves in shaly sand aquifers requires a reliable estimation of effective porosity and permeability; the amount of shaliness as a related quantity can be determined from well log analysis. The conventionally used linear model, connecting the natural gamma-ray index to shale content, often gives only a rough estimate of shale volume. A non-linear model is suggested, which is derived from the factor analysis of well-logging data. An earlier study of hydrocarbon wells revealed an empirical relationship between the factor scores and shale volume, independent of the well site. Borehole logs from three groundwater wells drilled in the northeastern Great Hungarian Plain are analyzed to derive depth logs of factor variables, which are then correlated with shale volumes given from the method of Larionov. Shale volume logs derived by the statistical procedure are in close agreement with those derived from Larionov’s formula, which confirms the validity of the non-linear approximation. The statistical results are in good accordance with laboratory measurements made on core samples. Whereas conventional methods normally use a single well log as input, factor analysis processes all available logs to provide groundwater exploration with reliable estimations of shale volume. 相似文献
10.
Naser Ebadati 《Journal of the Geological Society of India》2018,92(4):491-497
In this study, an attempt has been made through the data of one of exploratory wells as well as using petrophysical and FMI visual logs, the lithology, structures and failures of the field is investigated. For petro physical analysis of the area, after initial field investigation and controlling the drilled units, final approximation of the lithology of the area was made. Afterwards the raw data of well was used for the evaluation of petrophysical parameters by Geolog software. In the next step the effect of fractures on the oil production and their comparison with the initial porosity was analyzed. The results showed that the points with highest production and exploitation of the oil exists, have the greatest expansion of fractures. Comparison of the obtained results with the lithology specifications of other wells of the field shows that in zones with secondary fractures relative to the porosity the reservoir quality has been more appropriate and outputs the highest production and in comparison, the wells No.3, 4 and 5 in spite of having zones of higher porosity than the well number 2 of the lower reservoir quality. 相似文献
11.
Channel sand acts as a stratigraphic trap for hydrocarbon accumulation in many parts of the world. Delineation of this type of reservoir is crucial as channel sand may be scarce, and inaccurate location of the drilling wells could lose a huge currency. The Hassi Messaoud (HMD) field was subjected to multiphase tectonic events, where deep-seated structures were rejuvenated leading to intensive fault complexity. The main effective tectonic events upon the studied area are the Hercynian compression and deep erosion till the Ordovician Hamra Quartzite (HQZ) oil reservoir, followed by active Triassic rifting and filling the deeply eroded areas or the graben areas by eruptive volcanic rocks at Triassic time. Hercynian erosion and volcanic rocks distribution introduce a big uncertainty to the reservoir structural model. Amplitude versus offset (AVO) method is used as a helpful tool to differentiate channel sand from surrounding formations. Several attributes (P-impedance, S-impedance, longitudinal velocity Vp, shear velocity Vs and density ρ) are estimated from pre-stack seismic inversion. They have different sensitivity to the reservoir properties. Derived attributes such as Lamé parameters, incompressibility × density (λρ) and rigidity × density (μρ) can provide key lithology and fluid indicators (Goodway et al. 1997, Goodway CSEG Rec 26(6):39-60 2001). Petrophysically relating AVO attributes both to λρ and μρ and to each other in Lambda–Mu–Rho (LMR) cross-plot space can be a good tool for AVO interpretation (Rutherford and Williams Geophysics 54:680–688 1989 and Castagna and Swan Lead Edge 16(4):337–342 1997). After proper data conditioning, simultaneous inversion of pre-stack angle gathers is performed to get acoustic wave impedance (P-impedance), elastic wave impedances (S-impedance) and density ρ, then to calculate λρ and μρ volumes. In the studied area, λρ and μρ are used as a very important key to separate reservoir sands. The λρ and μρ curves are generated at each well location. Cross plots showed a fair separation of sand in the formation, i.e. higher μρ and lower λρ can detect sand. The output λρ and μρ volumes after simultaneous inversion follow the distribution of the sand which is consistent with the wells penetrating the target reservoir. This finding on the extension of the sand reservoir in terms of λρ and μρ. 3D cross-plot zonations are used for lithology discrimination. In this study, well logs were used to constrain lithology and to control the zonation filters by reducing the limits ambiguity. Other types of advanced attributes are calculated and tested. The obtained (μρ–λρ) volume acts as a good indicator for the sand distribution. It was finally used as sand presence index in the area. Also μρ has shown a good linear relationship with porosity. To note that the porosity volume is created based on the linear relationship with μρ. A product of derived porosity and the sand presence index (μρ–λρ) provides a good tool for reservoir characterization and lead to reservoir management, future planning of the field, and setting location for new wells. 相似文献
12.
三露天井田具有断层发育、地层缺失和重复明显、岩性种类较多等特点,岩性识别难度较大。为此,专门利用测井资料对三露天井田地层岩性进行了岩性识别研究。通过对14个天然气水合物钻孔不同岩性的测井响应特征分析,优选了自然伽马、中子和密度测井作为岩性识别敏感参数,并采用交会图技术制作了岩性识别图版,建立岩性划分标准,对三露天井田地层岩性进行识别与划分。利用测井资料能够识别7种主要岩性,包括砂岩、粉砂岩、泥质粉砂岩、粉砂质泥岩、泥岩、油页岩和煤等。根据岩性测井识别结果,三露天井田岩性分布特征在横向上表现为东部砂岩物性好,西部地区泥岩较为发育;纵向上表现为木里组地层砂泥比为4.48,含有煤层204.5 m;江仓组地层砂泥比为0.84,泥岩和油页岩较为发育,更有利于水合物赋存。测井岩性识别结果为寻找三露天井田天然气水合物有利储层奠定了基础。 相似文献
13.
《地学前缘(英文版)》2019,10(3):1113-1124
Estimation of petrophysical parameters is an important issue of any reservoirs. Porosity, volume of shale and water saturation has been evaluated for reservoirs of Upper Assam basin, located in northeastern India from well log and seismic data. Absolute acoustic impedance (AAI) and relative acoustic impedance (RAI) are generated from model based inversion of 2-D post-stack seismic data. The top of geological formation, sand reservoirs, shale layers and discontinuities at faults are detected in RAI section under the study area. Tipam Sandstone (TS) and Barail Arenaceous Sandstone (BAS) are the main reservoirs, delineated from the logs of available wells and RAI section. Porosity section is obtained using porosity wavelet and porosity reflectivity from post-stack seismic data. Two multilayered feed forward neural network (MLFN) models are created with inputs: AAI, porosity, density and shear impedance and outputs: volume of shale and water saturation with single hidden layer. The estimated average porosity in TS and BAS reservoir varies from 30% to 36% and 18% to 30% respectively. The volume of shale and water saturation ranges from 10% to 30% and 20% to 60% in TS reservoir and 28% to 30% and 23% to 55% in BAS reservoir respectively. 相似文献
14.
Kim Senger Thomas Birchall Peter Betlem Kei Ogata Sverre Ohm Snorre Olaussen Renate S.Paulsen 《地学前缘(英文版)》2021,12(6):411-427
Marine controlled source electromagnetic(CSEM)data have been utilized in the past decade during petroleum exploration of the Barents Shelf,particularly for de-risking the highly porous sandstone reservoirs of the Upper Triassic to Middle Jurassic Realgrunnen Subgroup.In this contribution we compare the resistivity response from CSEM data to resistivity from wireline logs in both water-and hydrocarbon-bearing wells.We show that there is a very good match between these types of data,particularly when reservoirs are shallow.CSEM data,however,only provide information on the subsurface resistivity.Careful,geology-driven interpretation of CSEM data is required to maximize the impact on exploration success.This is particularly important when quantifying the relative re-sistivity contribution of high-saturation hydrocarbon-bearing sandstone and that of the overlying cap rock.In the presented case the cap rock comprises predominantly organic rich Upper Jurassic-Early Cretaceous shales of the Hekkingen Formation(i.e.a regional source rock).The resistivity response of the reservoir and its cap rock become merged in CSEM data due to the transverse resistance equivalence principle.As a result of this,it is imperative to understand both the relative contributions from reservoir and cap rock,and the geological sig-nificance of any lateral resistivity variation in each of the units.In this contribution,we quantify the resistivity of organic rich mudstone,i.e.source rock,and reservoir sandstones,using 131 exploration boreholes from the Barents Shelf.The highest resistivity(＞10,000 Ωm)is evident in the hydrocarbon-bearing Realgrunnen Subgroup which is reported from 48 boreholes,43 of which are used for this study.Pay zone resistivity is primarily controlled by reservoir quality(i.e.porosity and shale fraction)and fluid phase(i.e.gas,oil and water saturation).In the investigated wells,the shale dominated Hekkingen Formation exhibits enhanced resistivity compared to the background(i.e.the underlying and overlying stratigraphy),though rarely exceeds 20Ωm.Marine mudstones typically show good correlation between measured organic richness and resistivity/sonic velocity log signatures.We conclude that the resistivity contribution to the CSEM response from hydrocarbon-bearing sandstones out-weighs that of the organic rich cap rocks. 相似文献
15.
川东北五宝场地区须家河组须五段具有特低孔特低渗致密砂岩储层特征,常规叠后纵波阻抗难以区分泥岩背景下的储层,储层预测和含气性检测难度大。本文基于Gassmann方程进行流体替换并对工区缺失横波资料的井进行横波预测,并分别正演饱含不同流体性质的道集。研究发现储层饱含水为一类AVO响应特征,储层饱含气为二类AVO特征,AVO规律明显,进而采用实钻井的样本点建立岩石物理模板,选取纵横波速度比联合纵波阻抗圈定致密砂岩储层,利用更低的纵横波速度比能有效指示含气性。结果表明：砂体及储层展布规律能够得到很好的表征,叠前含气性预测对井吻合率达到90.9%。叠前预测在川东北五宝场地区须家河组须五段致密砂岩含气性识别中是有效的,有助于提高钻探成功率与开发效益。 相似文献
16.
自然电位、电阻率、自然伽马等测井曲线的形态和特征与沉积相带及砂体展布关系密切,它们对不同岩性地层特征响应十分敏感。通过对天津市宝坻南部两个第四系取芯孔岩芯编录、沉积相分析和测井曲线特征分析,总结了不同地质历史时期沉积亚相及微相的测井响应特征,建立了该区域测井沉积相模式。结合研究区大量水文钻探电测资料,简要讨论了电测资料在该区域第四系地质结构研究应用中取得的良好效果,为平原区进一步开展第四系地层结构研究工作提供了新的方法。 相似文献
17.
利用测井数据中的自然伽玛、中子、声波和密度测井曲线所蕴含的岩性信息,用模糊聚类算法实现岩性的自动划分。该方法识别准确度高,可靠性强。通过对川西坳陷十八口井的实际应用,此方法在低孔低渗的致密碎屑岩岩性划分中取得了良好的效果。 相似文献
18.
Amir Karimian Torghabeh Reza Rezaee Reza Moussavi-Harami Biswajeet Pradhan Mohammad Reza Kamali Ali Kadkhodaie-Ilkhchi 《Central European Journal of Geosciences》2014,6(3):393-402
Identifying reservoir electrofacies has an important role in determining hydrocarbon bearing intervals. In this study, electrofacies of the Kockatea Formation in the Perth Basin were determined via cluster analysis. In this method, distance data were initially calculated and then connected spatially by using a linkage function. The dendrogram function was used to extract the cluster tree for formations over the study area. Input logs were sonic log (DT), gamma ray log (GR), resistivity log (IND), and spontaneous potential (SP). A total of 30 reservoir electrofacies were identified within this formation. Integrated geochemical and petrophysics data showed that zones with electrofacies 3, 4, 9, and 10 have potential for shale gas production. In addition, the results showed that cluster analysis is a precise, rapid, and cost-effective method for zoning reservoirs and determining electrofacies in hydrocarbon reservoirs. 相似文献
19.
N. Vinayachandran A. C. Narayana K. Md. Najeeb P. Narendra 《Journal of the Geological Society of India》2013,81(2):183-191
Kuttanad near the western coast of Kerala is a low lying area below mean sea level. The hydrogeological scenario in this wet land dominated tract, known as kole lands, was investigated by using the lithological and geophysical data generated under the R&D exploration programme of Central Ground Water Board (CGWB) during the year 2000, as also other related data generated till the year 2009. The hydrogeology of the tract is complex, and the presence of carbonaceous and organic matter in the soil and sub-soil influences the geochemical and geo-electric characteristics of the sub-surface geological formations as reflected by SP and resistivity logs. The lithologs and geophysical logs of bore wells were used to define the aquifer geometry. While the lateral and vertical variations of the aquifer systems identified were high, the bottom aquifer was relatively brackish over a large area. The gamma log behavior in these granular zones is anomalous and misguiding in nature. The radioactivities recorded against clay horizons were in the range of 130 to 200cps and in the granular zones 150 to 350 cps. The presence of monazite bearing sands at certain depths was responsible for anomalously high gamma counts against granular zones. The water quality in the granular zones was inferred from the electrical logs. The depth of occurrence of high radiation sand beds was also demarcated. 相似文献
20.
从分析薄互层的特征入手,采用反褶积方法对单条测井曲线做提高分辨率的处理,并调整电阻率测井曲线,使其与提高了分辨率的泥质含量及孔隙度测井曲线的纵向分辨率协调、在此基础上,按一定的解释模型计算出孔隙度和饱和度等参数。实际计算表明,本方法改善了储集参数的评价,降低了含水饱和度。 相似文献