Jean‐Philippe Nicot  Ian J. Duncan 《Greenhouse Gases: Science and Technology》2012,2(5):352-368

Areal footprints of current and future hydraulically fractured oil and gas reservoirs and potential CO₂ geological‐sequestration intervals often overlap in sedimentary basins. Significant vertical separations between prospective subsurface volumes, however, will limit their interaction, particularly if the carbon‐storage site is deeper than the hydrocarbon resource. Recent intense development of shale resources translates into a reduced need for sequestration capacity. It has also resulted in technological innovations directly transferable to the carbon‐storage industry, in particular progress on well completion, such as new approaches to cementing, more mature horizontal drilling methods, and development of field‐treatment techniques for saline water. In addition, knowledge collected by operators on stratigraphy and faults – for example, using 3D seismic – and on abandoned wells is directly useful in reducing risk in future carbon‐storage projects. Both industries can benefit from development of regional transmission pipelines, pipeline rights‐of‐way, and a trained workforce. From a regulatory standpoint, hydraulic fracturing of shale and tight formations is not considered injection. Under the US UIC program, because hydraulically fractured wells fall under the production category, they do not follow the same set of rules for protecting water resources as oil and gas industry disposal wells do (UIC Class II). Both subsurface uses share some risk elements, however. Environmental risks result mostly from abandoned wells and faults, poorly characterized for carbon storage, and from defective well completions and surface spills during oil and gas production. Operators of both fields are also concerned about disposal of large fluid volumes possibly generating seismic events. © 2012 Society of Chemical Industry and John Wiley & Sons, Ltd  相似文献   

    

Abou El‐Makarim A. Aboueissa  Michael R. Stoline 《Environmetrics》2004,15(7):659-673

This article is concerned with the estimation of the mean μ and standard deviation σ utilizing a singly‐left‐censored sample of normally distributed data having a known detection limit (DL). A new computer algorithm for obtaining the Cohen ( 1959 ) maximum likelihood estimates of μ and σ is provided which does not require auxiliary tables. The algorithm utilizes S‐PLUS or R languages. Closed form estimates of the mean and standard deviation obtained under a new replacement method are given for normally distributed left‐censored samples, which appear to be superior to existing replacement method estimates. The replacement method estimates are based on replacing the left‐censored observations by a non‐constant value. The performances of these methods are compared utilizing many simulated data sets. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

    

Khandaker M. Zahid  Seyyed A. Hosseini  Vanessa Nuez‐Lpez  Susan D. Hovorka 《Greenhouse Gases: Science and Technology》2012,2(6):460-473

Enhanced oil recovery (EOR) through carbon dioxide (CO₂) injection provides an excellent opportunity for commercial sequestration of anthropogenic CO₂. A fluvio‐deltaic, deep‐seated salt dome and a strand‐plain, roll‐over anticline from the Gulf Coast region are currently under investigation for the design and implementation of monitoring, verification, and accounting (MVA) plans, in coordination with the commercial surveillance of independent, large‐volume (>1 million ton/year) CO₂‐EOR operations. Characterization with wireline logs demonstrates the vertical extent and areal continuity of reservoir sands and geometries of faults that offset the reservoir. To develop the monitoring plan, we focused on several elements: (i) characterization of the zones above the confining unit for above‐zone pressure monitoring, (ii) collection and development of input data for ‘quick‐look’ dynamic modeling of CO₂ plume extent and pressure elevation, and (iii) identifying intersections of faults with wellbores in intervals above the regional confining unit for thermal monitoring. Other uncertainties addressed during characterization are the upper extent of faults and the juxtaposition of layers to assess the potential for cross‐fault fluid migration. Successful use of such techniques for MVA, based on uniting elements of existing regulatory monitoring expectations, would lead to the establishment of commercial best practices for effective and rapid characterization of EOR sites in the Gulf Coast region. © 2012 Society of Chemical Industry and John Wiley & Sons, Ltd  相似文献   

    

Saralees Nadarajah  Abdel H. El‐Shaarawi 《Environmetrics》2006,17(2):147-156

The exact distributions of the ratio X/Y are derived when X and Y are independent random variables and come from type I, type II or type III extreme value distributions. A detailed application of the results is provided to extreme rainfall data from Korea. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

    

Teresa Alpuim  Abdel El‐Shaarawi 《Environmetrics》2009,20(7):835-852

This paper examines monthly average temperature series in two widely separated European cities, Lisbon (1856–1999) and Prague (1841–2000). The statistical methodology used begins by fitting a straight line to the temperature measurements in each month of the year. Hence, the 12 intercepts describe the seasonal variation of temperature and the 12 slopes correspond to the rise in temperature in each month of the year. Both cities show large variations in the monthly slopes. In view of this, an overall model is constructed to integrate the data of each city. Sine/cosine waves were included as independent variables to describe the seasonal pattern of temperature, and sine/cosine waves multiplied by time were used to describe the increase in temperature corresponding to the different months. The model also takes into account the autoregressive, AR(1), structure that was found in the residuals. A test of the significance of the variables that describe the variation of the increase in temperature shows that both Lisbon and Prague had an increase in temperature that is different according to the month. The winter months show a higher increase than the summer months. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

    

Kristina Rasmusson  Chin‐Fu Tsang  Yvonne Tsang  Maria Rasmusson  Lehua Pan  Fritjof Fagerlund  Jacob Bensabat  Auli Niemi 《Greenhouse Gases: Science and Technology》2015,5(4):419-436

Geological storage in sedimentary basins is considered a viable technology in mitigating atmospheric CO₂ emissions. Alternating high and low permeability strata are common in these basins. The distribution of injected CO₂ among such layers affects e.g. CO₂ storage efficiency, capacity and plume footprint. A numerical study on the distribution of injected CO₂ into a multi‐layered reservoir, accounting for coupled wellbore‐reservoir flow, was carried out using the T2Well/ECO2N code. A site‐specific case as well as a more general case were considered. Properties and processes governing the distribution of sequestrated CO₂ were identified and the potential to operationally modify the distribution was investigated. The distribution of CO₂ was seen to differ from that of injected water, i.e. it was not proportional to the transmissivity of the layers. The results indicate that caution should be taken when performing numerical simulations of CO₂ injection into layered formations. Ignoring coupled wellbore‐reservoir flow and instead adopting a simple boundary condition at the injection well, such as an inflow rate proportional to the transmissivity of each layer, may result in significant underestimation of the proportion of CO₂ ending up in the shallower layers, as not all relevant processes are accounted for. This discrepancy has been thoroughly investigated and quantified for several CO₂ sequestration scenarios.  相似文献   

    

Amirsaman Rezaeyan  Seyyed Alireza Tabatabaei‐Nejad  Elnaz Khodapanah  Mosayyeb Kamari 《Greenhouse Gases: Science and Technology》2015,5(6):714-731

Caprock integrity is a primary criterion for evaluating depleted oil and gas reservoirs for long‐term safety of carbon dioxide geosequestration. The occurrence of capillary leakage is inevitable in caprock. This phenomenon occurs whenever the buoyancy pressure due to accumulated CO₂ plumes dominates the capillary pressure of caprock, and thereby the plumes intrude into the pore throats. In this study, experimental investigation of the effective parameters, including overburden pressure, ambient temperature, and CO₂ impurities in the form of non‐condensable and non‐reactive CH₄ and N₂ gases on the capability of shale and anhydrite cores to preserve CO₂ gas is conducted. In this regard, capillary breakthrough pressure and CO₂ gas effective permeability analysis were performed applying two distinct techniques, step by step and residual capillary pressure. Experiments were conducted at the temperatures of 35, 70, and 90 °C and overburden pressures in the range of 3500–5800 psi. Two main seal rocks, including shale and anhydrite core samples, from middle Asmari and Gachsaran formations of the Zagros Basin located in the southwest of Iran were used. Regarding the high capillary breakthrough pressure and low gas effective permeability after outbreak of the leakage, all three parameters have noticeable effects on capillary sealing efficiency of the caprocks. The results indicate that impurities such as CH₄ and N₂ have a significant effect on capillary breakthrough pressure of caprock and gas effective permeability. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd  相似文献   

    

Jean‐Franois Quessy  Anne‐Catherine Favre  Mriem Saïd  Maryse Champagne 《Environmetrics》2011,22(7):882-893

The sample properties of various inference procedures in Lombard's smooth‐change model are studied in this work. In particular, the power of six test statistics for the detection of change‐points in the mean and the variance of a series of independent observations is investigated under several alternatives. The robustness of the procedures under heterogeneity and serial dependence is considered as well. An investigation of the efficiency of an estimator of the change‐points is also presented. Conditional on these estimated change‐points, least squares estimators of the means in Lombard's model are derived and their efficiency is carefully studied. The procedures are illustrated on two environmental data sets, namely the annual volume of discharge from the Nile River and the annual temperature anomalies for the northern hemisphere. It will be seen that Lombard's model is flexible, that the test statistics of Lombard (1987) are powerful, and that the proposed estimators have nice properties; hence Lombard's model has a high potential for applications in the environmental sciences. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

    

A. H. El‐Shaarawi 《Environmetrics》2002,13(7):801-802

I welcome this article as it sheds new light on the important but difficult problem of the identification of pollution sources and the estimation of their contributions from field monitoring data. The article raises a number of technical issues, which are pertinent to the use of its methods in applications. In particular, a number of assumptions are used but without indicating how they can be tested from the data. I will confine my comments to: (a) the model specification and how it might be used in practice; (b) the estimation of the model's parameters. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

    

Abou El‐Makarim Aboueissa 《Environmetrics》2011,22(3):482-484

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