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1.
Large numbers of bottom-hole temperatures (BHTs) and temperatures measured during drill-stem tests (DSTs) are available in areas explored for hydrocarbons, but their usefulness for estimating geothermal gradients and heat-flow density is limited. We investigated a large data set of BHT and DST measurements taken in boreholes in the American Midcontinent, a geologically uniform stable cratonic area, and propose an empirical correction for BHTs based on relationships between BHTs, DSTs, and thermal logs. This empirical correction is compared with similar approaches determined for other areas. The data were analyzed by multivariate statistics prior to the BHT correction to identify anomalous measurements and quantify external influences. Spatial patterns in temperature measurements for major stratigraphic units outline relations to regional structure. Comparision of temperature and structure trend-surface residuals reveals a relationship between temperature highs and local structure highs. The anticlines, developed by continuous but intermittent movement of basement fault blocks in the Late Paleozoic, are subtle features having closures of 10–30?m and contain relatively small hydrocarbon reservoirs. The temperature anomalies of the order of 5–7?°C may reflect fluids moving upward along fractures and faults, rather than changes in thermal conductivity resulting from different pore fluids. 相似文献
2.
S. Bachu 《Tectonophysics》1985,120(3-4):257-284
A detailed study of the groundwater and terrestrial heat flow was carried out over an area of 23,700 km2 west of Cold Lake, Alberta, which is part of the western Canada sedimentary basin. The information for the study was provided from data from 3100 wells drilled in the area. The screening and processing of thousands of stratigraphic picks, drillstem test data, bottom hole temperatures and formation water chemistry data was performed mainly using a specially designed software package. As a result, every stratigraphic unit is characterized by appropriate hydraulic and thermal parameters.
A sequence of aquifers, aquitards and aquicludes was differentiated. The groundwater flow in the Paleozoic aquifers is regional in nature and mainly horizontal. The flow in the Cretaceous aquifers is of intermediate type, mainly downward oriented. In general, the permeability of the Cretaceous and Paleozoic strata has such low values that the fluid velocity is less than 1 cm/yr.
The convective heat transport in the hydrostratigraphic sequence is negligible with respect to the conductive heat transfer, as shown by the Peclet number of the fluid and heat flow in porous media. The flow of the terrestrial heat flux from the Precambrian basement of the sedimentary basin to the atmosphere is controlled by the variability in the thermal properties of the formations in the basin.
The geothermal gradients were computed by hydrostratigraphic unit using a linear regression fit to the temperature data. As expected, they show higher values for the less conductive layers, and lower values for the more conductive ones. The weighted average, or the integral geothermal gradient of the whole sedimentary column, was computed by considering the difference between the temperature measured at the Precambrian basement and the annual average temperature at the surface. The areal distribution of the integral geothermal gradient (with an average of 22.0 mK/m) shows a strong correlation with the lithology.
The areal temperature distribution for each hydrostratigraphic unit was analyzed by mapping the deviation of the measured value from the computed geothermal gradient. The lateral heat flow from warmer to colder areas is one order of magnitude smaller than the vertical heat flow. In the more homogeneous units, the lateral heat flow presents a trend that seems to reflect the geometry and lithology. 相似文献
3.
Use of groundwater temperature data in geothermal exploration: the example of Sydney Basin,Australia
Cara Danis 《Hydrogeology Journal》2014,22(1):87-106
Multidimensional simulations in geothermal exploration require vast quantities of measurements, including temperature, to produce realistic estimates. In Australia, the database of temperature measurements is small, limited by sparse distribution and tainted by non-equilibrium conditions. Groundwater temperature data from the groundwater-monitoring/water-supply bore network provide a creative cost effective way to bridge the information gap. Down-hole temperature profiles are valuable when thermal equilibrium conditions are present. Equilibrium conditions are common in groundwater bores as they are installed to be long term. Effective use of groundwater temperature data for geothermal exploration requires an understanding of (1) the thermal conditions being measured, (2) the factors that affect the measurement, and (3) how the measurements can be used. Highly constrained models, rather than extrapolation maps, are the cost effective, risk-reducing solution for geothermal exploration in Australia. The Sydney Basin provides a case study of how an undervalued, ‘cold’ coal-bearing sedimentary basin became ‘hot’ through high-resolution modelling using groundwater temperature measurements. Groundwater temperature data are the new information source capable of filling the gaps left by the limited deep temperature measurements. Hydrogeological data play a critical role in geothermal exploration, as models representing a highly complex world approach reality. 相似文献
4.
东台坳陷现今地温场特征与油藏分布关系 总被引：1，自引：0，他引：1
东台坳陷为中国东部苏北盆地油气资源最丰富的地区。为了加深对东台坳陷地温场和油藏关系的理解,根据符合地温场研究要求的54口井连续测温资料和243口井试油温度数据,获得了深度1000～3500m地温、E2s-K2t各层位界面地温和各层地温梯度。地温场分布以凹陷或次凹成独立单元,地温随深度加深而线性增高,地温异常不明显。地温梯度总体呈现"浅层低、深层高"的特点,E2s-E2d地温梯度总体在22～30℃/km之间,E1f-K2t在28～38℃/km之间,平均约为30℃/km。不同深度的地温和地温梯度分布模式相似,正向构造单元高,负向构造单元低;而不同层位的地温分布规律则相反,即凹陷内温度高,凸起和隆起上的温度低。基底构造形态、沉积盖层厚度、深大断裂、地下水、地层放射性生热等因素决定了该坳陷总体为温盆特征。大部分地区目前还处在油气液态窗内,绝大多数油藏分布高于60℃的油气勘探开发黄金区域。 相似文献
5.
《International Geology Review》2012,54(9):1032-1058
Subsurface reservoir temperatures of two important Mexican geothermal systems (Los Azufres and Las Tres Vírgenes) were estimated by applying all available solute geothermometers for 88 and 56 chemical data measurements of the spring waters and fluids of the deep geothermal wells, respectively. Most of the chemical data for spring water of these two geothermal fields are for HCO3 water, followed by SO4 and Cl types. For the Los Azufres geothermal field (LAGF), the reservoir temperatures estimated by Na-K geothermometers for springs of HCO3 and SO4 waters, and by Na-Li and Li-Mg geothermometers for Cl water, are close to the average bottom-hole temperature (BHT) of the geothermal wells. However, all reservoir temperatures for spring waters from the Las Tres Vírgenes geothermal field (LTVGF) estimated by all solute geothermometers indicated significantly large differences (low temperatures) compared to the BHT. Evaluation of inferred reservoir temperatures for spring waters of the LAGF and LTVGF suggests that not all springs nor all solute geothermometers provide reliable estimation of the reservoir temperatures. Even though chemical equilibrium probably was not achieved in the water–rock system, Na-K geothermometers for HCO3 water (peripheral water mainly of meteoric origin with little geothermal component) and SO4 water (geothermal steam heated) and Na-Li and Li-Mg geothermometers for Cl-rich spring water (fully mature geothermal water) of the LAGF indicated reservoir temperatures close to the BHT. However, in comparison with the geothermometry of spring water of the LAGF and LTVGF, fluid measurements from geothermal wells of these two fields indicated reservoir temperatures in close agreement with their respective BHTs. For the best use of the solute geothermometry for spring water, it is advisable to: (1) chemically classify the springs based on water types; (2) identify and eliminate the discordant outlier observations by considering each water type as a separate sampled population; (3) apply all available solute geothermometers employing a suitable computer program such as SolGeo instead of using some specific, arbitrarily chosen geothermometers; and (4) evaluate the temperatures obtained for each solute geothermometer by considering the subsurface lithology, hydrological conditions, and BHTs or static formation temperatures whenever available. 相似文献
6.
在资料收集、野外地质、地温调查及现场地面物探工作的基础上,对山东省蓬莱市村里集镇黄泥沟村地区地热地质条件进行综合研究,分析了地热资源的开采前景,目的是基本查明工作区内的断裂构造、地层层序、热储分布、热储埋深、热储温度,预测地热井的成井条件,为地热资源开发利用总体规划及进一步勘探提供依据。分析内容包括地质构造条件、地温场特征、地球物理特征以及热储特征。认为工作区具备开发地热资源的前景条件,地热井成井深度在1500m左右时可获得30℃~40℃的热水。建议投入施工一眼探采结合井,井深设计1500m,井位选择于1000~1200m钻遇NE向断裂下盘,可获得较完善的地热资源赋存信息。 相似文献
7.
A detailed study on the solute geothermometry of thermal water (18 springs and 8 drilled wells) of La Primavera geothermal field (LPGF) in Mexico has been carried out by employing a geochemical database compiled from the literature and by applying all the available solute geothermometers. The performance of these geothermometers in predicting the reservoir temperatures has been evaluated by applying a geochemometrics (geochemical and statistical) method. The springs of the LPGF are of bicarbonate type and the majority have attained partial-equilibrium chemical conditions and the remaining have shown non-equilibrium conditions. In the case of geothermal wells, water is dominantly of chloride-type and, among the studied eight geothermal wells, four have shown full-equilibrium chemical conditions and another four have indicated partial-equilibrium conditions. All springs of HCO3− type water have provided unreliable reservoir temperatures, whereas the only one available spring of SO42− type water has provided the reservoir temperature nearer to the average BHT of the wells. Contrary to the general expected behavior, spring water of non-equilibrium and geothermal well water of partial-equilibrium chemical conditions have indicated more reliable reservoir temperatures than those of partially-equilibrated and fully-equilibrated water, respectively. Among the chemical concentration data, Li and SiO2 of two springs, SO42− and Mg of four springs, and HCO3 and Na concentrations of two geothermal wells were identified as outliers and this has been reflected in very low reservoir temperatures predicted by the geothermometers associated with them (Li–Mg, Na–Li, Na–K–Mg, SiO2 etc.). Identification of the outlier data points may be useful in differentiating the chemical characteristics, lithology and the physico-chemical and geological processes at the sample locations of the study area.In general, the solute geothermometry of the spring waters of LPGF indicated a dominantly (94%) of underestimated deep reservoir temperatures, whereas in the case of the geothermal wells, many temperatures (54%) are underestimated, some are (43%) overestimated and a very small number (3%) are similar to an average bottom-hole temperatures (BHT) of the wells. 28 out of the total applied 29 geothermometers for spring waters have predicted the deep reservoir temperatures that are characterized by statistically significant large differences compared to the average BHTs of the geothermal wells. In the case of waters of the geothermal wells, 23 out of the total applied 28 geothermometers have predicted the reservoir temperatures similar (statistically no significant differences) to the BHTs of the corresponding geothermal wells. 相似文献
8.
Continuous sedimentary gradients are only crudely expressed by standard facies and microfacies methods which are more appropriate to situations where changes occur in relatively discrete steps. In carbonate sediments and rocks, continuous gradients are often represented by the arrangement of component grain types in a relay, that is, a systematic shifting of the relative importance of the components. Subdivision of such relays into (micro)facies can only be arbitrary. Correspondence analysis is shown to be useful for detecting, isolating and describing relays. Particular use is made of the arch effect in which samples and components from data sets with a strong unidimensional structure (a relay) plot in the form of an arch in the plane of the first two factor axes. A relay index, indicating the position of samples in the relay, can be extracted from the analysis and plotted on maps and stratigraphic logs to reveal details of the sedimentary gradient in areal and/or stratigraphic context. Examples are given from: (i) Recent shallow-marine carbonate sediments from northern Norway, illustrating a relatively simple depositional setting where surface sediments are viewed in plan; and (ii) Lower Carboniferous carbonates of southwest England, representing a more complex regional study of a particular stratigraphic interval viewed in cross-section. In both examples the relays can be related to identifiable environmental gradients. 相似文献
9.
Tong Jinnan Xiao Shiyu Liu Zhili Faculty of Earth Sciences China University of Geosciences Wuhan 《中国地质大学学报(英文版)》2000,11(1)
INTRODUCTIONIn South China,the marine Middle Triassic is distributedmainly over the Yangtze region along the present YangtzeRiver,where the Hercynian orogeny did not happen but thesubsequent Indosinian m ovement greatly changed thepaleogeographic pattern and depositional history.The TriassicIndosinian movement troansfered most parts of the Yangtzeplatform from marine to terrestrial in early or late MiddleTriassic (Table 1) and finally ended the marine history of theseareas.The first … 相似文献
10.
Preliminary Statistics of Temperatures and Pressures for Formation of Eclogites, Granulites and Peridotites in China 总被引：1，自引：0，他引：1
HuBaoqun WangFangzheng SunZhanxue LiuChengdong BaiLihong 《中国地质大学学报(英文版)》2004,15(2):183-192
The rock-forming temperatures and pressures represent the p-T points of the local regions in the lithosphere at a certain age, providing some important information on rock formation. Based on the preliminary statistics on the temperatures and pressures for the formation of eclogites, granulites and peridotites in China, the variant ranges are given, in this paper, of temperatures, pressures and linear geothermal gradients of eclogites, granulites and peridotites. In addition, since the eclogite is different from granulite and peridotite in the p-T diagram, these three rocks can be classified into two groups: the first group includes eclogites and the second group granulites and peridotites. Then, the p-T correlation functions of these two groups of rocks are provided. Finally, the two groups of rocks have different geothermal gradients at the same pressure gradient or have different pressure gradients at the same geothermul gradient. The temperatures and pressures for the formation of the rocks can be calculated from the mineral chemical compositions, but the depths (H) for the rock formation can be calculated only under the hypotheses of given p-H (or T-H) correlation functions. The explanations for the ultrahigh pressure metamorphism vary obviously with different hypotheses. 相似文献
11.
Chukwuemeka Frank R. Odumodu Ayonma Wilfred Mode 《Journal of the Geological Society of India》2016,88(1):107-118
Geothermal gradients and present day heat flow values were evaluated for about seventy one wells in parts of the eastern Niger delta, using reservoir and corrected bottom–hole temperatures data and other data collected from the wells. The results showed that the geothermal gradients in the shallow/continental sections in the Niger delta vary between 10 - 18° C/km onshore, increasing to about 24° C/km seawards, southwards and eastwards. In the deeper (marine/paralic) section, geothermal gradients vary between 18 - 45° C/km. Heat flow values computed using Petromod 1–D modeling software and calibrated against corrected BHT and reservoir temperatures suggests that heat flow variations in this part of the Niger delta range from 29–55 mW/m2 (0.69–1.31 HFU) with an average value of 42.5 mW/m2 (1.00 HFU). Heat flow variations in the eastern Niger delta correspond closely to variations in geothermal gradients. Geothermal gradients increase eastwards, northwards and seawards from the coastal swamp. Vertically, thermal gradients in the Niger delta show a continuous and non-linear relationship with depth, increasing with diminishing sand percentages. As sand percentages decrease eastwards and seawards, thermal gradient increases. Lower heat flow values (< 40 mW/m2) occur in the western and north central parts of the study area. Higher heat flow values (40 - 55 mW/m2) occur in the eastern and northwestern parts of the study area. A significant regional trend of eastward increase in heat flow is observed in the area. Other regional heat flow trends includes; an eastwards and westwards increase in heat flow from the central parts of the central swamp and an increase in heat flow from the western parts of the coastal swamp to the shallow offshore. Vertical and lateral variations in thermal gradients and heat flow values in parts of the eastern Niger delta are influenced by certain mechanisms and geological factors which include lithological variations, variations in basement heat flow, temporal changes in thermal gradients and heat flow, related to thicker sedmentary sequence, prior to erosion and evidenced by unconformities, fluid redistribution by migration of fluids and different scales of fluid migration in the sub-surface and overpressures. 相似文献
12.
Transient mid-Cretaceous thermal uplift induced by lateral heating from passing oceanic lithosphere is often invoked as a mechanism for the formation of the Côte d'Ivoire–Ghana basement ridge in the Equatorial Atlantic. This heating event should have affected mid-Cretaceous sedimentary rocks along the ridge. However, organic maturity and clay mineral data on the thermal evolution of these rocks suggest that burial temperatures did not exceed 80 °C and that palaeo–geothermal gradients are not anomalous. Optical petrography and the stratigraphic pattern of temperature-sensitive parameters indicate that higher palaeotemperature estimates are related to admixtures of preheated, detrital organic and inorganic matter. Erosion brought the sediments to their present shallow burial depths. Lack of evidence for significant thermal alteration implies that either thermal exchange between oceanic and continental lithosphere along the Côte d'Ivoire–Ghana Transform Margin was negligible, or that lateral heating by oceanic lithosphere was not strong enough to affect the sedimentary cover of the basement ridge. 相似文献
13.
构造断阶对沉积的控制:来自地震、测井和露头的实例 总被引：10，自引：0，他引：10
构造断阶是裂谷盆地(特别是裂谷盆地发育早期)或断陷盆地边缘发育的一种构造样式,反映盆地边缘因断块差异沉降所形成的沉积斜坡地形的阶梯变化。在地震剖面可以解释出许多不同类型的断阶带,并在此框架下根据地震反射结构解释地震相和沉积相。构造断阶带的不同类型控制了不同的沉积样式。构造断阶的识别约束了地震解释的多解性。测井资料的运用可以证实断阶带的沉积控制作用,约束地震解释,也可以进行沉积微相及空间分布的精细研究.地震、测井的实例分别来自松辽盆地徐家围子断陷和渤海湾盆地沾化凹陷。来自胶莱盆地野外露头的实例从另一方面证实了这种控制作用。与钻井或测井资料相比,露头资料具有连续性。露头的详细分析可得到构造断阶对沉积和地层结构控制的细节。构造断阶(带)与沉积作用关系的模式可以提供油气勘探的地质模型。 相似文献
14.
15.
Hakim Gabtni Badia Chulli Zenatti Chokri Jallouli Kevin L. Mickus Mourad Bedir 《Arabian Journal of Geosciences》2011,4(3-4):507-516
An analysis of Bouguer gravity anomaly data and geothermal gradient data obtained from bottom hole and drill stem tests temperature is used to determine the crustal structure of the Sahel Basin in eastern Tunisia and its role in the maturation and location of the large number of oil and gas fields in the region. The regional Bouguer gravity anomaly field is dominated by gradual increase in values from the northwest to southeast and is may be caused by crustal thinning as revealed by regional seismic studies. In addition, higher geothermal gradients in the same region as the Bouguer gravity anomaly maximum add an additional constraint for the existence of crustal thinning in the region. A detailed analysis of the Bouguer gravity anomaly data was performed by both upward continuation and horizontal gradients. These two techniques were combined to show that the study area consists of two structural regions: (1) the North–South Axis (NOSA)–Zeramedine region which is characterized by northwest-dipping, northeast-striking faults, thicker crust (30–31 km) and low geothermal gradients, and (2) the Mahres–Kerkennah region which is characterized by vertical, northwest-striking faults, thinner crust (28–29 km) and higher geothermal gradients. The correlation of a variety of features includes mapped and geophysically defined faults, volcanic rocks, a thinned crust and high geothermal gradients within the same location as known oil and gas fields indicate that the faults are a major factor in the location of these petroleum accumulations. 相似文献
16.
Analysis of factors affecting heat flow density determination in the Liaohe Basin,North China 总被引：1，自引：0，他引：1
Structural relief of the pre-Cenozoic basement and groundwater flow have been found to be the two most important factors affecting the heat flow density determinations in the Liaohe Basin. The reason for the significant effect of basement relief upon subsurface temperature and heat flow density patterns is the strong contrast of thermal conductivity between basement rock and the sedimentary cover. Simplified model computations indicate that the heat flow density in the region of basement uplift is 1.35 times greater than that in the region of depressions. Field observations indicate that the temperatures at shallow depths (less than 1200 m) are strongly perturbed by groundwater flow leading to reduced temperatures and geothermal gradients in the Neogene formation. Comparison of observed and calculated gradients reveals that reduced gradients and heat flow density occur in the groundwater recharge area whereas these parameters are enhanced in the discharge area. After taking the perturbing factors into account, a regional heat flow value of 65 ± 9 mW/m2 is obtained. 相似文献
17.
川西新场气田蓬莱镇组陆相地层高分辨率层序地层学研究 总被引：10，自引：2，他引：8
利用钻井岩芯、测井和地震资料,运用高分辨率层序地层学理论及方法,对新场地区蓬莱镇组进行不同级次的基准面旋回层序划分,识别出 45～ 47个短期、5个中期、2个长期基准面旋回层序,并对不同级次的基准面旋回层序的结构类型、叠加样式和平面分布模式进行了较为深入的讨论。在单井分析的基础上,以二分时间单元分界线为优选等时对比标志对不同级次的基准面旋回进行了较高精度的等时对比,所对比的等时成因地层单元的最高精度可达到相当准层序组 (十万年级 )的短期基准面旋回。建立了新场地区蓬莱镇组高分辨率层序地层格架,成功地将单井一维信息转化为气田范围内的三维地层关系信息。并分析了短期基准面旋回过程中可容纳空间 (A)与沉积物补给通量 (S)的比值 (A/S)变化对储集砂体的作用.文中还利用沉积动力学的地层响应过程特征分析,重点讨论了中、短期基准面旋回过程中有利储集砂体的沉积相序列、组合特征、产状类型、控制因素及其与物性的关系。指出发育于长期基准面缓慢上升或下降过程中的三角洲沉积体系,为形成储集砂体的必备背景条件,而控制沉积体系中储层时空展布和演化规律的因素则主要为中期基准面旋回。在层序地层格架中,中期基准面旋回层序界面两侧的储层其储集性最好。以此为依据,提。 相似文献
18.
中低温热储及其井中热场 总被引：3，自引：0，他引：3
中低温地下热水有着广阔的开发利用前景。其成因及赋存规律的研究,是合理勘探、开发的基础。本文从地层、构造及水文地质条件入手根据地热传导原理,研究了传导型热领教的发育条件,划分了主要热储类型在此基础上,对井（孔）中热场及井液温度变化规律进行了分析,给出了井液温度分布曲线及井液温度变化与地层的对应关系。这一成果,对勘探开发地下热水有积极的意义。 相似文献
19.
Subsurface thermal structure in Tohoku district are characterized by existing data such as geothermal resources maps, drill hole thermal gradients, Curie point depths and hypocenters distribution maps. The collected data are registered in a database system, then, compared in plan view, cross-section and bird's-eye pictures. The comparison indicates that subsurface temperatures extrapolated from drill hole thermal gradients are generally concordant to the Curie point depth, assumed to be 650 °C. Tohoku district is generally divided into 5 type areas; fore arc lowland, fore arc mountain country, Quaternary volcanic terrain, back arc lowland and back arc mountain country. The surface thermal manifestations in Quaternary volcanic terrain are mainly controlled by the magma chambers as heat sources, while, surface thermal features such as hot springs in non-volcanic areas are controlled by degrees of heat flows, and hydrothermal flows in permeable Cenozoic formations and along permeable fault zones. 相似文献
20.
Textural and mineralogical properties of the sediment, facies characteristics (both derived from well data), stacking patterns (derived from well and seismic data) and plan‐view shapes (derived from seismic data) are all essential components when reconstructing reservoir geometries from subsurface data sets. Without the availability of all these sources of information, reservoir predictions can potentially deviate significantly from the true geometries. In particular, inferences about internal sandbody geometry from plan‐view considerations (isopach maps and seismic attribute maps) may lead to erroneous conclusions without knowledge of facies and textural properties of the sediment. Analysis of well‐exposed sedimentary systems has the potential to establish links between internal facies characteristics and large‐scale geometry and to improve models coupling information at these variable scales. The Palaeogene Battfjellet Formation, Svalbard, has been studied with the aim to unravel internal characteristics and external form by investigating sediment properties, facies and stacking patterns. The formation shows a combination of texturally and mineralogically very immature sediments, a predominance of wave‐generated or wave‐induced sedimentary structures and a stacking pattern of highly variable numbers of parasequences at localities few kilometres apart that best can be explained in terms of small shifting deltaic lobes that produced a complex pattern of overlapping sandbodies. The strong evidence of wave action in the receiving basin could in itself indicate strike‐extensive sandstone bodies; however, the complex sandbody arrangement and the immaturity of the sediments preclude such an interpretation. Traditional facies models coupling plan‐view geometries with internal facies characteristics (such as the coupling of strike extensive barrier systems with wave‐dominated sedimentary structures or the coupling of elongated fluvial‐dominated deltas with offshore‐directed current‐generated structures) are much too simple and may lead to erroneous interpretations if the complexity revealed by all sources of data is not appreciated. 相似文献