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371.
The paper deals with the methods of formation pressure evaluation for a single well by using the very common accepted parameters, such as drilling exponent , and flowline temperature , etc. which is part of compiling the end well report.  相似文献   
372.
Cleat orientation, cleat frequency and cleat angle distribution of deep coal seams are only available by the use of drilling cores and from coal mine samples. Coal drilling cuttings are a cheap and fast alternative to measure cleat angle distributions with the use of image analysis techniques. In this study oriented coal samples and drilling cuttings of the RECOPOL field experiment are compared and used to explain and validate the proposed method. In other words, cleat angle distributions from drilling cuttings are measured by image analysis. The geological framework of the polish coals is described. The image analysis methodologies for the measurement of fracture faces of cuttings and from CT-scan images, derived from these coals, are explained. The results of the methods on the cuttings are compared with cleat orientation distributions from CT-scans and artificial fragments from coal blocks of the same seams. These evaluations show high agreements between the methods. The cleat angle distributions of drilling cuttings of four seams are compared with the cleat orientation distributions of a regional structural geological study. The high correlation in this study shows that cleat angle distributions of coal seams can be used as input parameters for reservoir modelling.  相似文献   
373.
利用以雷达资料快速更新四维变分同化(RR4DVar)技术和三维数值云模式为核心的模拟分析系统,通过同化京津冀区域6部新一代天气雷达逐6 min的径向速度和反射率因子资料,并融合区域自动站逐5 min观测和中尺度数值模式结果,对发生在京津冀地区的18个对流风暴"事件"进行了高分辨率数值模拟,开展了个例分析和全部模拟结果的检验评估。个例分析结果表明,模拟的低层三维动力、热动力和水汽特征可以明确解释复杂地形条件下对流风暴的局地新生、组织化和线状中尺度对流系统(MCS)的形成。高分辨率模拟结果也明确指示了线状中尺度对流系统中对流风暴单体不断新生(再生)和"后向传播"的机制,以及地形强迫在风暴形成和演变中的重要作用。基于一部风廓线雷达、两部地基微波辐射计、一个秒级探空和一个边界层观测塔等局地高频非常规观测数据对18个对流风暴"事件"模拟结果的检验表明,0-3 km的风速、风向和温度的模拟误差(包括偏差和均方根误差)总体较小。其中,最低模式层(187.5 m)风速偏差和均方根误差分别在-0.5和0.9 m/s以内,最高检验层(2.8125 km)风速偏差和均方根误差分别在-0.9和1.6 m/s以内,风速误差随高度逐渐增大;风向偏差在14°-22°,风向均方根误差小于38°;温度偏差和均方根误差分别在-1和1.8℃以内。系统模拟的低层风速、风向和温度的偏差和均方根误差在对流风暴内部稍大于外部。上述研究表明,该系统模拟结果对对流风暴生消、发展及生命史特征的临近预报和预警具有重要指示意义。  相似文献   
374.
通过汶川科学钻探钻孔地质实体(岩芯)的构造研究、非弹性应变恢复法(ASR法)地应力测试,结合区域构造和汶川地震NW向余震带的综合分析,提出沿映秀-北川断裂走向的狭窄范围内存在一组NW-SE向构造,其总体产状为:走向N48°W,倾角中等,与映秀-北川断裂带的总体走向和ASR地应力测试获得的一组最大主应力方位(侧伏方向224°)和最大水平应力方位(44°)接近垂直。NW-SE向构造,除少数发育为宏观的断裂构造外,多数表现为密集的裂隙系(或隐断裂)和隐伏断裂,以逆冲性质为主,局部略具左行走滑特征。映秀-北川断裂两侧相向倾斜的NW-SE向裂隙系表明其两侧存在有方向相反的运动,映秀-北川断裂属两侧具有不同形成机制和相向位移的双侧走滑型断裂。映秀-北川断裂的同震垂向位移受NE-SW向构造和NW-SE向构造双重因素制约,在汶川地震的主震带与NW向余震带叠置部位具最大的垂向位移量。从时间尺度分析,在汶川地震的全过程中,仅开始时刻表现为自NW→SE方向的强烈逆冲作用,随后的主要时间段内均表现为沿断裂带方向的运动和自SW→NE方向的逆冲。NW-SE向构造的形成是龙门山深部应力和能量长期积聚的结果,强震发生时,初始时刻的自NW向SE方向的强烈挤压,瞬即转换成自SW向NE方向的运动和强烈挤压。NE-SW向挤压构造应力场,是由NW-SE向挤压作用长期积累和诱导,并叠置在区域NW-SE向主导的挤压构造应力场之上的局部构造应力场,但在发震后,它主导了地震能量自震源区沿断裂走向向NE方向的快速传递和扩展及NW向强余震的发生,地震能量在NE-SW向强烈挤压过程中得到最终释放。因此,映秀-北川断裂在地震的不同阶段,其性质存在差异,在地震宁静期或弱震期(应力积累和闭锁期)以自NW往SE方向的逆冲性质为主,兼有右行走滑特征,但在强震期(应力释放和解锁期),除发震时表现为强烈的继承性逆冲作用,随后即转化为以平行断裂带走向自SW向NE方向的快速运动和扩展及自SW往NE方向的逆冲作用为主。  相似文献   
375.
Fracture and in-situ stress studies were conducted for unconventional prospect evaluation in the Silurian Qusaiba Shale, northern Saudi Arabia. Borehole image logs, oriented cores, seismic, and drilling observations were used in the studies. The fractures include natural fractures and induced fractures. The induced fractures were studied to assess the stress regime in terms of directions and magnitudes. The present day maximum horizontal in-situ stress trend varies from NNW-SSE to NNE-SSW, and shows a regional pattern dominated by Arabian plate tectonics. The relative magnitudes of the current day stresses are characteristic of an extensional to strike-slip regime. Natural fractures of microscopic (microfractures) to macroscopic (macrofractures) scales include extension fractures (joints/veins), and faults manifested as shear and hybrid (extensional-shear and compressional-shear) fractures. Joints clustering into zones are rare, unless when associated with fault zones. Over half of the faults (56%) show clustering into fault zones with their widths (thickness) varying by up to 5 orders of magnitude, and lengths and displacements varying by up to 4 orders of magnitudes respectively. The study identified five distinctive, regional, fracture sets: one gently dipping (bedding-parallel or at low angle to bedding) and up to four moderately to steeply dipping fracture sets: an easterly striking set is the oldest, followed by three younger major sets striking NNW-SSE, N-S, and NNE-SSW. The younger fractures are nearly parallel to the present day maximum horizontal in-situ stress. Crack-seal mechanism (natural hydrofracturing) dominates initial fracture growth, some with several phases of partial to complete mineralization or coating, dominated by calcite, quartz, and dolomite. Aqueous and hydrocarbon gaseous and fluid inclusions are common in the fractures' mineral filling. The regional nature of in-situ stresses and natural fractures means their occurrence, orientation, relative dominance, and relative age and relative apertures are easier to predict and manipulate for well planning and completion, including hydrofracturing. Forward modeling shows that natural fracture network are not critically stressed under reservoir conditions but when subjected to massive hydrofracture stimulation they and the bedding discontinuities form the seeds for the growth of a complex hydrofracture network that potentially grows out of presumed stress-barriers. Lack of stress rotation around faults in wells supports the modeling results. Microseismic monitoring gives time-lapse (incremental) microseismic events of two types; random and linear patterns parallel to maximum horizontal in-situ stress and the predominant natural fracture trend. Bulk microseismic cloud has no unique link to fault trends mapped from high resolution borehole images. This finding challenges the usability of uncalibrated microseimic monitoring of massive hydrofracturing to map faults.  相似文献   
376.
著名的盘古山大型钨矿与深部隐伏花岗岩体具有密切成因关系,但因该岩体隐伏深,相关研究资料较为欠缺,很大程度上影响了对矿床岩浆-热液-成矿作用的深入认识。南岭科学钻探(SP-NLSD-2)揭露该岩体后,本文对其开展了岩石学和元素地球化学研究。结果表明,该岩体具有超酸性、富碱、贫钠富钾等特征,属于准铝-过铝质高钾钙碱性花岗岩。形成该岩体的花岗岩浆为高度分异演化的残浆,W、Bi等元素含量明显高于南岭燕山期花岗岩,为盘古山钨铋矿床的形成提供了丰富的矿质。岩浆演化至云英岩化阶段时,岩浆中的Mo、Bi、Cu、Pb及REE含量增加,而W、Sn含量则因已转移到岩浆期后热液而降低。岩体形成于板内伸展环境。  相似文献   
377.
The regular variations in magmatic activities along the Northwest Pacific plate have been little studied in spite of their importance. In this contribution, systematic analyses were conducted on tholeiitic basalts from three Ocean Drilling Program sites (Sites 304, 1149, and 801), including the petrographic features, major and trace elements, Nd isotopic compositions, and mineral structure and compositions of whole rocks. Volcanic rocks from Sites 304, 1149, and 801 belong to tholeiites and exhibit depleted light rare earth elements (LREE), large ion lithophile elemental contents (LILE), and relatively depleted Nd isotopic ratios (143Nd/144Nd=0.513139–0.513211), similar to those of normal mid-ocean ridge basalts (N-MORB). Comprehensive data on mineral compositions, whole-rock geochemistry, and geochronology demonstrate that a regular variation trend exists in the north-south direction along the Northwest Pacific plate. The 143Nd/144Nd values (0.513139–0.513211) and trace-element ratios for whole rocks (Sm/Th=15.35–30.00; Zr/Hf=28.53–35.76; Zr/Y=2.58–3.67; Th/La=0.04–0.06; Th/Y=0.33–0.70), as well as the trace-element ratios (Zr/Hf, La/Yb, Ti/Zr) of clinopyroxenes from Sites 1149 and 801 tholeiites show larger variations compared to those from Site 304 tholeiites (143Nd/144Nd=0.513185–0.513195; Sm/Th=18.19–20.58; Zr/Hf=31.07–33.26; Zr/Y=2.62–3.03; Th/La=0.05–0.06; Th/Y=0.48–0.57). Mineral zoning textures were obvious in tholeiites from Sites 1149 and 801 but were rarely observed in Site 304. These regular features were likely attributed to the differences in the heterogeneity of the magma source, the process of magmatic evolution, the plate-spreading rate, and the effective and ineffective mixing.  相似文献   
378.
松辽盆地科学钻探工程是围绕地球深部资源、古环境与古气候等一系列重要地球科学问题而实施的重大科学工程。作为该工程的主体钻孔, 松科二井东孔设计为松辽盆地最深钻孔, 设计深度6 400.0 m, 计划穿透白垩系地层、钻至盆地基底。由于上白垩统井段取心量非常少, 因此地球物理测井的作用尤为重要。该孔正式开钻后, 采用先进的成像测井设备对一开和二开钻井井段(上白垩统井段)先后实施4次裸眼井综合测井和套管井测井作业, 并系统地开展测井综合评价, 取得以下科学成果: (1)原位获取了常规测井、特殊测井和固井质量检查测井资料共20种, 资料丰富、质量优良, 建立了上白垩统连续的岩石物理参数标准剖面; (2)完成了上白垩统地层划分、岩性识别、沉积和构造精细解释; (3)识别出泉头组油气储层、嫩江组和青山口组烃源岩层、嫩江组高放射性异常层, 以及上白垩统地热开发潜力层; (4)探索了青山口组古气候分析的有利测井指标; (5)及时提供准确的井径、钻孔轨迹和固井质量等关键钻探工程信息。研究成果对于松辽盆地地球物理勘探科学“标尺”建立、古环境与古气候研究、钻探工程施工起到至关重要的作用, 为整个钻探工程科学目标的实现奠定良好基础。  相似文献   
379.
高压泥浆系统是自升式钻井平台中的重要系统,对维持生产作业、保证平台的安全具有极为重要的意义。作为一个高性能,高应力系统,对高压泥浆系统进行应力分析以便对管线系统的布置、支吊架位置和结构进行评估是很有必要的。鉴于此,从分析理论、参考标准、分析工具和校核工况组合等多个方面进行探讨,计算该高压泥浆系统的一次应力和二次应力,法兰的强度以及模态分析,得到合理的管路布置,探索出自升式钻井平台中高压泥浆系统应力分析的可行方法。  相似文献   
380.
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