Modeling hydraulic fracture propagation using cohesive zone model equipped with frictional contact capability     

《Computers and Geotechnics》2017

We present a new pore pressure cohesive element for modeling the propagation of hydraulically induced fracture. The Park-Paulino-Roesler cohesive zone model has been employed to characterize the fracturing behavior. Coulomb’s frictional contact model has been incorporated into the element to model the possible shear reactivation of pre-existing natural fractures. The developed element has been validated through a series of single-element tests and an available analytical solution. Furthermore, intersection behaviors between the hydraulic fracture and the natural fracture under various conditions have been predicted using the present element, which shows good agreement with experimental results.  相似文献   

Uncertainty of rainfall-induced landslides considering spatial variability of parameters     

《Computers and Geotechnics》2017

A cross-correlation analysis is conducted to determine the impacts of the heterogeneity of hydraulic conductivity K_s, soil cohesion c′ and soil friction angle (tan φ′) on the uncertainty of slope stability in time and space during rainfall. We find the relative importance of tan φ′ and c′ depends on the effective stress. While the sensitivity of the stability to the variability of K_s is small, the large coefficient of variation of K_s may exacerbate the variability of pore-water pressure. Therefore, characterizing the heterogeneity of hydraulic properties and pore-water distribution in the field is critical to the stability analysis.  相似文献   

Numerical simulation of fracture path and nonlinear closure for simultaneous and sequential fracturing in a horizontal well     

《Computers and Geotechnics》2017

Reservoir stimulation requires a model to evaluate the fracture path and closure for the simultaneous or sequential propagation of the hydraulic fracture (HF). This paper presents a fluid-solid coupled model to simulate multi-stage HF propagation. A non-linear joint model is proposed to evaluate the fracture closure when the created fractures are elastically propped. HF closure continues until the balance of external stress matches the proppant's resistance. The reservoir along the horizontal wellbore is not stimulated equally by the multi-stage fracturing. The HFs in the subsequent stage are ‘repelled’ and restrained by the HFs in the previous stage.  相似文献   

Comparison of surface and borehole locations of induced seismicity   总被引：1，自引：0，他引：1  

Leo Eisner  B. J. Hulsey  Peter Duncan  Dana Jurick  Heigl Werner  William Keller 《Geophysical Prospecting》2010,58(5):809-820

Monitoring of induced microseismic events has become an important tool in hydraulic fracture diagnostics and understanding fractured reservoirs in general. We compare microseismic event and their uncertainties using data sets obtained with surface and downhole arrays of receivers. We first model the uncertainties to understand the effect of different acquisition geometries on location accuracy. For a vertical array of receivers in a single monitoring borehole, we find that the largest part of the final location uncertainty is related to estimation of the backazimuth. This is followed by uncertainty in the vertical position and radial distance from the receivers. For surface monitoring, the largest uncertainty lies in the vertical position due to the use of only a single phase (usually P‐wave) in the estimation of the event location. In surface monitoring results, lateral positions are estimated robustly and are not sensitive to the velocity model. In this case study, we compare event location solutions from two catalogues of microseismic events; one from a downhole array and the second from a surface array of 1C geophone. Our results show that origin time can be reliably used to find matching events between the downhole and surface catalogues. The locations of the corresponding events display a systematic shift consistent with a poorly calibrated velocity model for downhole dataset. For this case study, locations derived from surface monitoring have less scatter in both vertical and horizontal directions.  相似文献   

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崔旭升  潘国荣  李法礼 《大地测量与地球动力学》2010,30(2):156-159

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规范基层国土资源工作流程的几点想法     

王东 《山东国土资源》2010,26(7):67-68

针对当前国土资源所规范化建设中出现的科室业务衔接过程中的种种问题,就如何明确科所责权、完善机制,全面提升科所业务水平,提出了"一对一"业务指导、通过"收(退)件登记卡"完善管理机制、制定不同行政许可事项工作程序流程图等措施。  相似文献   

新疆柯坪新生代推覆岩席的走向连接与成因分析   总被引：4，自引：0，他引：4       下载免费PDF全文

方茂龙王树红  韩晓青赵世勤 《中国地质》2009,36(2):322-333

柯坪断隆新生代推覆构造是南天山南缘冲断系统的一部分,断隆上多排逆冲岩席被数条横向断裂复杂化,致使不同地段岩席排数不等,各排岩席在走向上的对应关系不明,形成了十分奇特的山弯构造.逆冲岩席的变形特点是南天山新生代造山运动的重要表征.笔者通过卫星影像分析和野外路线地质调查,对横向断裂切割各排逆冲岩席之切点部位的构造特征及岩席内部中小型构造所显示的成因信息进行了详细分析,据此,对复杂岩席在走向上进行了连接,对其数量进行了识别.在此基础上,提出了复杂岩席成因的斜冲褶皱模式,即在北西向应力场持续作用下,岩席向南东斜冲,并在其水平位移分量作用下,沿走向发生褶皱和斜冲错断:横向断裂是多排岩席褶皱翼部扭性断层的发展和连通.  相似文献   

钢与砼组合梁加固工业厂房的应用研究     

孙群 《中国勘察设计》2009,(9):83-85

结合工程实例,介绍钢与砼组合梁在加固工业厂房中的应用研究,并对加固梁的构造进行了设计、计算及分析。  相似文献   

A Compilation of Radiocarbon Dates from Disko Bugt,Central West Greenland/Meteorological Observations in 1996 at the Arctic Station,Qeqertarsuaq (Godhavn), Central West Greenland/A Discussion on Pingos in Mellemfjord,Disko, Central West Greenland/Open System Pingos in Mellemfjord,Disko, Central West Greenland: A Reply to Gurney and Worsley     

Morten Rasch  Birger Hansen  Ole Humlum  Niels Nielsen  Peter Funch  Stephen D. Gurney 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):143-159

188 new and previously published radiocarbon dates on Holocene material from Disko Bugt, central West Greenland, are presented together with relevant informations (laboratory number, place name, dated material, geografic coordinates, altitude and δ¹³C-value) about the dates.

In October 1990 an automatic weather station was established at the Arctic station (65 °15′N,53 °31′W), Qeqertarsuaq (Godhavn), Central West Greenland. The Station register parameters each 20 min., and the parameters have been described in an earlier paper in this journal by Nielsen et al. (1995). The present paper summarises main points of the climate during 1996.

Open system, or more correctly, hydraulic pingos, are genetically poorly understood. A continuing problem concerns their need for a perennial groundwater supply (intra- or sub-permafrost). This has to be maintained despite the existence of continuous permafrost in many areas where they are located. Recent work on Disko Island has suggested a new type of hydraulic pingo developing only in a “marsh environment”. It is argued that the marsh setting is not relevant to the formation of these features and that they are simply hydraulic pingos.

Abstract

A group of marsh initiated open system pingo remnants from the Iterdlagssûp kûgssua valley mouth, in Mellemfjord, Disko Island, Central West Greenland was described in Christiansen (1995). Gurney and Worsley (1997) state that the location of this group of pingo remnants in the Iterdlagssûp kûgssua valley mouth is of no relevance to their genesis, and that they presumably were the result of an assumed late Holocene sea level regression, causing permafrost to be established in the valley bottom. In this reply the arguments by Gurney and Worsley (1997) on the Iterdlagssûp kûgssua valley pingos are commented, and it is argued by way of sea level information, frost penetration and water supply that the special setting must indeed have caused pingo initiation and growth. Furthermore, the area has experienced a relative sea level rise during the late Holocene.  相似文献   

PAN graphs An aid to GIS analysis     

CHRISTOPHER M. GOLD 《International journal of geographical information science》2013,27(1):29-41

Abstract

Many data structures are possible for the storage of topological information for computer-based maps. The PAN graph is here suggested as an aid in the selection of a strategy appropriate to the application. Examples are given for the mapping of triangular networks and Thiessen polygons. Application of the technique is appropriate to both education in, and design of, spatial data structures for automated cartography and geographical information systems  相似文献