油田高含水期基于微观渗流机理的宏观岩心水驱油数值模拟研究     

谷建伟  翟世奎  李怀明  薛发玉 《中国海洋大学学报(自然科学版)》2006,36(4):540-544

建立地层孔隙网络模型描述微观孔喉特征,利用逾渗方法计算基于微观渗流机理的相对渗透率曲线,并将之应用到数值模拟计算中,给出考虑微观渗流特征的方程,并进行数值求解,得到地层中流体分布特征。实例分析表明该方法可以得到基于微观特征的剩余油分布数量和形式,为调剖堵水、化学驱提供技术参数,实现微观渗流机理与宏观计算的结合。  相似文献   

Origin of a large breccia-vein system in the Sanerlin uranium deposit, southern China: a reinterpretation   总被引：1，自引：0，他引：1  

Jian-Wei Li  Mei-Fu Zhou  Xian-Fu Li  Zi-Jin Li  Zhao-Ren Fu 《Mineralium Deposita》2002,37(2):213-225

The early Tertiary Sanerlin uranium deposit is located near the southwestern margin of the Chaling-Yongxing pull-apart basin defined by the Chaling-Yongxing and Chenxian-Linwu sinistral strike-slip faults in southern China. The uranium ores are hosted in 15 breccia-vein bodies, which are separately located in the cores of three secondary anticlines of the Upper Permian Dangchong Formation. Individual breccia-vein bodies are composed of fragments of silicified shale and sandstone from the Dangchong Formation, and quartz veinlets as cements. These fragments, together with quartz veins, form a mosaic texture. Hydrothermal pitchblende is the only commercial uranium mineral, mainly occurring as disseminated grains within quartz veins or coating fragments. Other metallic minerals include molybdenite, pyrite, chalcopyrite, galena, sphalerite, and red microcrystalline hematite. Fluid inclusions in quartz veins have homogenization temperatures ranging from 150 to 280 °C, and calculated salinity values between 5.6 and 13.4 wt% NaCl equivalent. Stable isotope analyses show that the mineralizing fluid was characterized by '¹⁸O values of -2.2 to +2.6‰ and 'D_H2O values of -134 to -110‰. These analytical data demonstrate that hydrothermal fluids were mainly derived from formation waters (brines) of the Chaling-Yongxing basin. Fluid overpressuring was caused by an abnormal geothermal gradient and impermeable shales in the deposit area. The geometry, texture, and structure of the breccia-vein system, along with the fluid pressure estimates, suggest that hydraulic fracturing generated the mineralized breccia-vein system. Pitchblende and associated minerals were deposited when gaseous phases were released abruptly from the ore fluids due to the hydraulic fracturing.  相似文献   

A Chirp Transform Algorithm for Processing Squint Mode FMCW SAR Data   总被引：2，自引：0，他引：2  

Zhi-Hong Jiang Kan Huang-Fu Jian-Wei Wan 《Geoscience and Remote Sensing Letters, IEEE》2007,4(3):377-381

Frequency-modulated continuous-wave (FMCW) synthetic aperture radar (SAR) is a lightweight cost-effective high-resolution airborne imaging radar. In squint case, the frequency scaling algorithm, which is suitable for processing nonchirped raw data, cannot be used directly in FMCW SAR data processing because of low system sampling frequency. On the other hand, the continuous antenna motion of FMCW SAR can cause serious distortions in the reconstructed images. In this letter, an improved algorithm called the chirp transform algorithm is proposed. When the effects of the residual video phase are negligible, the algorithm uses a chirp transform to perform the time scaling operation to alleviate the sampling frequency problem. It requires only fast Fourier transforms and multiplications. The range cell migration introduced by the continuous motion is also compensated completely in range-Doppler domain. The algorithm performances are analyzed and are supported by point target simulation experiments.  相似文献   

Mississippian (Early Carboniferous) stromatolite mounds in a fore-reef slope setting, Laibin, Guangxi, South China   总被引：1，自引：0，他引：1  

Jian-Wei Shen  Hairuo Qing 《International Journal of Earth Sciences》2010,99(2):443-458

The Mississippian (Early Carboniferous) is generally a period of scarce carbonate buildups in South China. This study documents outcrops of stromatolite mounds at Mengcun and Helv villages, in Laibin City, Guangxi Province, South China. The stromatolite mounds contain various stromatolite morphologies including laminar, wavy-laminar, domal or hemispheroidal, bulbous, and flabellate-growth columns. Intramound rocks are brachiopod floatstone and dark thin-bedded laminated micrite limestone. Individual stromatolites at Mengcun village are generally 3–6 cm thick and morphologically represent relatively shallow-water laminar (planar and wavy-undulated stromatolites) and deeper-water domal, bulbous and columnar forms. Where mounds were formed, the stromatolites continued growing upward up to 60 cm thick. Thrombolitic fabrics also occur but are not common. Stromatolite microscopic structure shows the bulk of the lamination to consist of wavy microbialite and discrete thin micritic laminae. These mounds are intercalated in deep-water fore-reef talus breccia, packstone formed as a bioclastic debris flow and thin-bedded limestone containing common chert layers of the Tatang Formation (late Viséan). Further evidence supporting the deep-water setting of the stromatolite mounds are: (1) a laterally thinning horizon of brachiopod floatstone containing deep-water, small, thin-shelled brachiopods, peloidal micritic sediments and low-diversity, mixed fauna (e.g., thin-shelled brachiopods, tube-like worms and algae) that have been interpreted as storm deposits, (2) common fore-reef talus breccias, (3) lack of sedimentary structures indicating current action, (4) preservation of lamination with sponge spicules, and (5) lack of bioturbation suggesting that the stromatolites grew in a relatively low energy, deep-water setting. The stromatolite mounds are the first described stromatolite mounds in Mississippian strata of South China and contain evidence that supports interpretations of (1) growth history of Mississippian microbial buildups and (2) environmental controls on stromatolite growth and lithification.  相似文献   

Monazite trumps zircon: applying SHRIMP U–Pb geochronology to systematically evaluate emplacement ages of leucocratic,low-temperature granites in a complex Precambrian orogen     

Agnieszka?M.?PiechockaEmail authorView author&#;s OrcID profile  Courtney?J.?Gregory  Jian-Wei?Zi  Stephen?Sheppard  Michael?T.?D.?Wingate  Birger?Rasmussen 《Contributions to Mineralogy and Petrology》2017,172(8):63

Although zircon is the most widely used geochronometer to determine the crystallisation ages of granites, it can be unreliable for low-temperature melts because they may not crystallise new zircon. For leucocratic granites U–Pb zircon dates, therefore, may reflect the ages of the source rocks rather than the igneous crystallisation age. In the Proterozoic Capricorn Orogen of Western Australia, leucocratic granites are associated with several pulses of intracontinental magmatism spanning ~800 million years. In several instances, SHRIMP U–Pb zircon dating of these leucocratic granites either yielded ages that were inconclusive (e.g., multiple concordant ages) or incompatible with other geochronological data. To overcome this we used SHRIMP U–Th–Pb monazite geochronology to obtain igneous crystallisation ages that are consistent with the geological and geochronological framework of the orogen. The U–Th–Pb monazite geochronology has resolved the time interval over which two granitic supersuites were emplaced; a Paleoproterozoic supersuite thought to span ~80 million years was emplaced in less than half that time (1688–1659 Ma) and a small Meso- to Neoproterozoic supersuite considered to have been intruded over ~70 million years was instead assembled over ~130 million years and outlasted associated regional metamorphism by ~100 million years. Both findings have consequences for the duration of associated orogenic events and any estimates for magma generation rates. The monazite geochronology has contributed to a more reliable tectonic history for a complex, long-lived orogen. Our results emphasise the benefit of monazite as a geochronometer for leucocratic granites derived by low-temperature crustal melting and are relevant to other orogens worldwide.  相似文献   

An adaptive over/under data combination method     

Jian-Wei He  Wen-Kai Lu  Zhong-Xiao Li 《应用地球物理》2013,10(4):469-476

The traditional ＂dephase and sum＂ algorithms for over/under data combination estimate the ghost operator by assuming a calm sea surface. However, the real sea surface is typically rough, which invalidates the calm sea surface assumption. Hence, the traditional ＂dephase and sum＂ algorithms might produce poor-quality results in rough sea conditions. We propose an adaptive over/under data combination method, which adaptively estimates the amplitude spectrum of the ghost operator from the over/under data, and then over/under data combinations are implemented using the estimated ghost operators. A synthetic single shot gather is used to verify the performance of the proposed method in rough sea surface conditions and a real triple over/under dataset demonstrates the method performance.  相似文献   

笼养条件下秃鹫繁殖期的行为日节律及时间分配的观察研究     

高峰  纪建伟  田恒玖  史洋  潘红  孙翔楠  张铁楼  胡严  张志明 《湿地科学与管理》2013,(1):65-68

2012年3～5月,采用直接瞬时扫描法和间接监控器摄像相结合的方式,对北京市野生动物救护中心顺义饲养繁育基地的一对秃鹫的繁殖行为的时间分配和活动规律进行了研究,结果显示:秃鹫在警戒、理羽、吃食、交配、孵化等行为存在着明显的节律性,警戒、理羽行为在行为比例中较高,警戒行为占绝对优势。取食行为多发生在上午的中间阶段,孵化行为不间断、并且轮流孵化幼鸟。孵化期内雌、雄个体的行为差异不大,秃鹫发情期各种行为所占的比例存在着一定的性别差异。  相似文献   

内蒙古锡林浩特-东乌旗剖面壳幔电性结构研究   总被引：3，自引：1，他引：2       下载免费PDF全文

徐新学  李俊健  刘俊昌  辛建伟  代涛  牛永强  张丽 《地球物理学报》2011,54(5):1301-1309

为研究二连-东乌旗贺根山一带成矿构造环境,提供矿产资源勘查、预测、评价的地质背景依据,跨贺根山和锡林浩特板块缝合带一线布设了26个超宽频带长周期大地电磁测深点,点距3～6 km,剖面长度100 km,在对获取的资料采用Robust变换、互参考处理的基础上,定性分析了视电阻率和相位曲线、二维偏离度、电性主轴,并采用二维共...  相似文献   

Mineralogical, chemical, and crystallographic properties of supergene jarosite-group minerals from the Xitieshan Pb-Zn sulfide deposit, northern Tibetan Plateau, China     

Lei Chen  Jian-Wei Li  R. O. Rye  W. M. Benzel  H. A. Lowers  Ming-Zhong He 《Mineralogy and Petrology》2013,107(4):487-499

Supergene jarosite-group minerals are widespread in weathering profiles overlying Pb-Zn sulfide ores at Xitieshan, northern Tibetan Plateau, China. They consist predominantly of K-deficient natrojarosite, with lesser amounts of K-rich natrojarosite and plumbojarosite. Electron microprobe (EMP) analyses, scanning electron microcopy (SEM) investigation, and X-ray mapping reveal that the jarosite-group minerals are characterized by spectacular oscillatory zoning composed of alternating growth bands of K-deficient and K-bearing natrojarosite (K₂O >1 wt.%). Plumbojarosite, whenever present, occurs as an overgrowth in the outermost bands, and its composition can be best represented by K_0.29Na_0.19Pb_0.31Fe_2.66Al_0.22(SO₄)_1.65(PO₄)_0.31(AsO₄)_0.04(OH)_7.37. The substitution of monovalent for divalent cations at the A site of plumbojarosite is charge balanced by the substitution of five-valent for six-valent anions in XO₄ at the X site. Thermogravimetric analysis (TGA) of representative samples reveal mass losses of 11.46 wt.% at 446.6 °C and 21.42 wt.% at 683.4 °C due to dehydroxylation and desulfidation, respectively. TGA data also indicate that the natrojarosite structure collapses at 446.6 °C, resulting in the formation of NaFe(SO₄)₂ and minor hematite. The decomposition products of NaFe(SO₄)₂ are hematite and Na₂SO₄. Powder X-ray diffraction (XRD) analyses show that the jarosite-group minerals have mean unit-cell parameters of a?=?7.315 Å and c?=?016.598 Å. XRD and EMP data support the view that substitutions of Na for K in the A site and full Fe occupancy in the B site can considerably decrease the unit-cell parameter c, but only slightly increase a. The results from this study suggest that the observed oscillatory zoning of jarosite-group minerals at Xitieshan resulted mainly from substitutions of K for Na at the A site and P for S at the X site.  相似文献   

黏弹性双相介质参数反演的同伦方法   总被引：4，自引：1，他引：3       下载免费PDF全文

田迎春  章梓茂  马坚伟  杨慧珠 《地球物理学报》2009,52(9):2328-2334

本文以介质的动态时域响应（位移、速度、加速度）作为反演的依据,对黏弹性双相介质的材料参数进行了反分析研究.根据附加条件,并考虑到由于测量误差和测量数据的不充分造成的反演问题的不适定性,将黏弹性双相介质的参数反演问题转化为非线性泛函的极小值问题,然后应用大范围收敛的同伦方法求出使泛函极小的根作为反问题的解.最后,以二维半空间黏弹性双相介质模型为例进行了数值反演分析,数值结果表明本文方法在参数的反演过程中目标函数稳定收敛,且具有一定的抗“噪声”干扰性能;与利用速度和加速度信息反演的结果相比,利用位移信息反演的结果具有较高的精度和抗噪声能力.  相似文献