排序方式： 共有16条查询结果，搜索用时 343 毫秒
1.
Application of discovery process models in estimating petroleum resources at the play level in China
Discovery process modeling has gained wide acceptance in the Chinese exploration community. In recent years, a variety of
discovery process models have been applied to the prediction of undiscovered petroleum resources at the play level in sedimentary
basins in China. However, challenging problems have been encountered, particularly when one method alone has been applied
to small plays in nonmarine sedimentary basins or in plays with an unusual order of discovery wells. This paper presents results
gotten by using the lognormal discovery process model of the Geological Survey of Canada and the geoanchored method for three
petroleum plays in basins with different geologic settings. Although the predicted shapes of the parentsize distributions
which use these two models, were not always similar, the expected values of the total resources and the number of fields (pools)
to be discovered are comparable. The combined use of two discovery process models in the same play compensates for the weaknesses
in one method compared with the other and vice versa. Thus, more reliable estimates are the result. 相似文献
2.
Richard B. McCammon Joseph M. Botbol Richard Sinding-Larsen Roger W. Bowen 《Mathematical Geosciences》1983,15(1):59-83
The latest or n ewest version of the char acteristic an alysis (NCHARAN)computer program offers the exploration geologist a wide variety of options for integrating regionalized multivariate data. The options include the selection of regional cells for characterizing deposit models, the selection of variables that constitute the models, and the choice of logical combinations of variables that best represent these models. Moreover, the program provides for the display of results which, in turn, makes possible review, reselection, and refinement of a model. Most important, the performance of the above-mentioned steps in an interactive computing mode can result in a timely and meaningful interpretation of the data available to the exploration geologist. The most recent application of characteristic analysis has resulted in the possible discovery of economic sulfide mineralization in the Grong area in central Norway. Exploration data for 27 geophysical, geological, and geochemical variables were used to construct a mineralized and a lithogeochemical model for an area that contained a known massive sulfide deposit. The models were applied to exploration data collected from the Gjersvik area in the Grong mining district and resulted in the identification of two localities of possible mineralization. Detailed field examination revealed the presence of a sulfide vein system and a partially inverted stratigraphic sequence indicating the possible presence of a massive sulfide deposit at depth. 相似文献
3.
The Geo-anchored method, based on a moment-type estimator, has been developed for estimating parent population properties from a successive sample of discoveries. By substituting the expectation of the waiting time z
(n+1) of the (n + 1)
th
discovery to occurrence for an unknown parameter in the anchored method, the Geo-anchored method allows estimation of inclusion probabilities directly from observed data, thus eliminating the need for a priori selection of a value of N, R, or some other feature of the parent population. Because direct estimation of N and R requires an ordered sample, the Geo-anchored method is more sensitive to the data-generating process than the anchored method. This paper presents a sensitivity study on the Geo-anchored method. The test is based on simulated discovery sequences with different assumptions regarding discovery efficiency, exploration maturity, and the shape of the parent field size distribution. As a reference for comparison, estimates from the Horvitz–Thompson estimator also are presented. 相似文献
4.
5.
Estimating number and field size distribution in frontier sedimentary basins using a Pareto model 总被引：1，自引：0，他引：1
Estimating the number of deposits likely to be found and their size distribution is important in exploration planning. In a frontier basin the geologic information for conducting a resource assessment is mostly limited to the regional level. Some methods, such as the play analysis approach (Crovelli and Balay, 1986) and the conceptual play model (Lee and Wang, 1983), can be used in conceptual plays or frontier basins, but these methods require the knowledge of the number of prospects, pool data characterizing the conditional field size distribution, and information documenting the exploration risk. For unexplored sedimentary basins, such as those in southern Africa, there are neither sufficient data covering reservoir volumetric parameters nor a number of mapped prospects that can be used to conduct such an assessment. In such a case a volumetric method using geologic analogy is applicable, by which a point estimate of hydrocarbon potential can be estimated, but this estimate provides no information on the likely size distribution. As a complement to the volumetric method, we discuss how to use the empirical Pareto law for estimating the number of fields and their size distribution in such a frontier region. 相似文献
6.
Nearly all the data in exploration geochemistry and remote sensing represent composites. However, composites may arise implicitly or be created explicitly. Bearing in mind that a common exploration task is the classification of data as being above or below some predetermined threshold the size of the composite may be critical to the recognition of a relatively rare, subcomposite, anomalous event. Two approaches are developed, based on statistical, and cost-analytical considerations. The statistical model allows for spatial correlation in the data, of importance when sampling is undertaken continuously along a drill core or flight line. Tables are presented for optimal composite sample size selection based on both models. The procedure is illustrated by an example taken from a drilling program. In general, the cost-analytical model leads to smaller composites than the statistical model. When spatial independence may be assumed the cost-optimal composite sizes are almost always smaller than those suggested by the statistical approach. 相似文献
7.
Based upon the Bayesian framework for analyzing the discovery sequence in a play, a Markov chain Monte Carlo sampler—the Metropolis–Hastings algorithm, is employed to sample model parameters and pool sizes from their joint posterior distribution. The proposed sampling scheme ensures that the parameter space of changing dimension can be traversed in spite of the unknown number of pools. The equal sample weights make it easy to obtain the confidence intervals and assess the statistical error in the estimates, so that the statistical behaviors of the discovery process modeling can be well understood. Two application examples of the Halten play in Norwegian Sea and the Bashaw reef play in the Western Canada Basin show that, the computational advantage of this method to the simple Monte Carlo integration is considerable. In order to increase the convergence speed of the sample chains to the posterior distributions, several parallel simulations with different starting values are recommended. 相似文献
8.
Joseph Moses Botbol Richard Sinding-Larsen Richard B. McCammon Garland B. Gott 《Mathematical Geology》1977,9(3):309-311
There are four concepts involved with the methodology used in this analysis: classical second derivative surfaces, boolean representation of the surfaces, determination of weighted model characteristics, and multiple variable regional appraisal.This paper was presented at the International Geological Correlation Program (IGCP) Project 98 entitled Standards for Computer Applications in Resource Studies held at Loen, Norway, September 27–October 1, 1976. 相似文献
9.
An oil seep site in the northern Gulf of Mexico is characterized by high backscattering levels on the GLORIA (Geological Long-Range Inclined Asdic) side-scan sonar images against a background of low backscattering. The high backscattering from the oil-seep area are most likely caused by a combination of small-scale roughness and porosity reduction due to the precipitation of CaCO3 formed during biodegradation of the oil-seep. Geostatistical methods have been applied to analyze side-scan images from both oil seep and nonseep areas. The results show that GLORIA images from oil seep areas can be distinguished from nonseep areas in terms of local histograms, variograms, and textural patterns. Pixels from seep and nonseep areas cluster into distinct groups on a textural feature plot. GLORIA side-scan images could be used as a reconnaissance tool to delineate oil and gas seep sites on the seafloor and thereby, reduce the dry-hole risk of petroleum exploration in deep-water frontier areas. 相似文献
10.
Lognormal discovery process modeling characterizes oil and gas discovery as sampling from a lognormal parent distribution with probability proportional to size and without replacement. In this article, we present a sensitivity study that is based on simulated discovery sequences with different assumptions regarding discovery efficiency, exploration status, and the shape of the parent field size distribution. The results indicate that lognormal discovery process modeling provides good overall estimates of the lognormal parameters if the parent field size distribution is lognormal. If the parent field size distribution is Pareto, an underestimation of the play potential may occur if a lognormal discovery process model is applied. Failure of the likelihood value converging to a maximum is more frequent when sample size is small and/or discovery efficiency is low. 相似文献