鄂尔多斯盆地北部上古生界天然气成藏期次——以杭锦旗探区为例

杭锦旗探区是中国石油化工股份有限公司在鄂尔多斯盆地北部的一个重点区块,油气生、储、盖条件良好,目前对于该区上古生界天然气成藏期次的认识存在分歧。通过生烃时间法、圈闭形成期法、流体包裹体法以及储层致密化时间和煤热解模拟结果等方法对该区上古生界油气成藏期次展开研究。结论认为杭锦旗探区上古生界存在2期大规模油气运聚;结合生烃高峰和流体包裹体均一化温度结果,明确了该区上古生界油气成藏时间,分别对应于中-晚侏罗世和早白垩世末-至今,前者为油气兼生期,后者为大规模天然气生成期。研究过程中结合多种方法和手段来判识油气成藏期次,避免了单一方法的局限性,结论及认识的可信度更高。     

MDT测井技术在LG地区多井解释中的应用

LG地区的预探井钻获工业气流后,在该井周围相继钻探了多口井,地质上迫切需要了解储层在横向上的变化情况、气水层在纵向上分布状况和气水界面等。为此,对LG地区10多口预探井及评价井进行了MDT地层测试,较好地解释了二叠系长兴组各个礁滩气藏以及三叠系飞仙关组各个鲕滩气藏之间的关系。研究表明：飞仙关组鲕滩储层中,LG1井与LG001 1、LG001 3、LG001 6井等属同一压力系统,而与LG2井、LG3井和LG6井为不同的压力系统;长兴组礁滩储层中,LG1井与LG2井气层不属同一压力系统,而与LG001 1井、LG001 3井为同一压力系统,LG12井与LG28井为同一压力系统,LG8井和LG11井分别为单独压力系统。该分析结果为单井地层压力分析、气水识别、压力系统分析及后期的储量计算和开发方案的实施提供了直接依据。     

Closed-form solutions for key performance measures of packet multiplexers with finite capacity queue

We revisit the packet multiplexer with a discrete-time single server queue of limited capacity, and we derive a set of exact closed-form solutions for the major performance measures, such as the distributions of queue length, waiting time and number of lost packets per arriving batch. Assuming equally utilised inputs, the results refer to batch arrivals of binomial and Poisson distributed size, whereas they generally hold for systems with two inputs. The analysis is based on both the commonly used Early Arrival and Late Arrival queueing models, and we show that these models are equivalent at any capacity in terms of both waiting time and loss probability if the Late Arrival queue can hold one additional packet compared to its Early Arrival counterpart.     

2D BASIN MODELLING IN THE EASTERN VARISCAN FOLD BELT (CZECH REPUBLIC): INFLUENCE OF THRUSTING ON PATTERNS OF THERMAL MATURATION

This study evaluates the geothermal history of Palaeozoic sedimentary rocks from the easternmost part of the Variscan external zone in the NE Czech Republic. The objective was to investigate the geothermal history of pre‐Variscan Palaeozoic carbonates in the study area, and to assess its relationship with that of the overlying Variscan flysch. In the study area, the Palaeozoic succession occurs at the surface or is overlain by Miocene sediments of the Carpathian Foredeep. Palaeozoic nappes and the main Variscan overthrust have been documented in the subsurface at the deep Pot?tát‐1borehole. Vitrinite reflectance measurements on 38 samples from the Pot?tát‐1 well and 19 samples from nearby surface outcrops and shallow boreholes were available. A 2D thermal model was created using PetroMod and the thermal maturity evolution was modelled by EASY%Ro. The thermal model was constructed based on interpretations of two NW‐SE seismic profiles (lines 5/83 and 5/84) oriented perpendicular to the main Variscan thrusts. The results were calibrated using measured vitrinite reflectance and were adjusted with 1D models from three shallow boreholes. At the Pot?tát‐1 borehole, modelled maximum palaeo‐temperatures of the Variscan flysch (Moravice Formation) ranged from 310°C at a depth of 7.3 km (the top of the preserved succession) to 395°C at the base of the succession, resulting in thermal maturities of >4%R_r. Peak maturation occurred prior to the end of Variscan thrusting. Modelling suggests that the basal heat flow for these thrust units reached a maximum value of 63 mW/m² at 325 Ma. In addition, the modelling suggests that the maturity of the Palaeozoic carbonates was controlled by the thickness of the overlying Variscan flysch nappes. Maximum palaeo‐temperatures for the Palaeozoic carbonates ranged from 265°C at the top of the interval (at a depth of 7.1 km) to 290°C at the base, resulting in a maturity of 3.8 to >4%R_r which is within the dry gas window. The study suggests that basal heat flows in the original (pre‐thrust) Early Carboniferous sedimentary basin were slightly higher than those in the post‐thrust location for the Variscan flysch nappes. This should be taken into account when evaluating the petroleum system in the South Moravian oil province (SW Czech Republic) where a complete sedimentary sequence has not been preserved.     

黄陵矿区煤矿井下围岩喷涌气体致灾机理及防治措施

鄂尔多斯盆地南缘黄陵矿区黄陵一号等煤矿在采掘过程中出现井下围岩大量气体喷涌现象,导致矿井停采停掘,对煤矿安全生产构成严重威胁。为了揭示喷涌气体的成因及致灾机理,以地面钻孔补充勘探和钻探资料及围岩气体地球化学参数测试数据为基础,采用气样地球化学特征分析、热演化史模拟、烃源岩对比、运移通道识别等多种方法,查明围岩气体的砂岩储集层平面及剖面分布特征,研究区内异常致灾围岩气体的成因类型和来源,分析围岩气体异常喷涌的致灾机理,建立以顶底板砂岩探抽为主的分源综合立体抽采防治模式。研究结果表明:(1)该区煤矿井下围岩气体喷涌具有突发性、隐蔽性、涌出集中和涌出量大等特点,涌出气体主要成分为甲烷,气体主要来源于围岩;(2)顶、底板围岩气体主要为原油伴生热解成因的油型气,生气源岩为上三叠统延长组长7等段腐泥型主力烃源岩,经燕山运动形成的北东向基底断层及其周围大规模垂直裂缝运移而来;(3)油型气主要储集砂岩层呈区带式分布,受构造和岩性双重控制;(4)针对围岩油型气以游离态储集在砂岩中、由采动裂隙导通涌出的特点,采用分源综合立体抽采的防治模式进行围岩气灾害治理,取得了良好的治理效果。     

渝东南盆缘转换带常压页岩气储层非均质性特征及主控因素

四川盆地东南部及其盆缘转换带(以下简称渝东南盆缘转换带)页岩气资源量较大,但其地质条件复杂、地层呈常压特征,给页岩气的经济开发带来了困难。为了深入认识该区页岩气储层的非均质性,借助X射线衍射、氩离子抛光扫描电镜、低温氮气吸附等手段,从岩石骨架、储集空间的角度研究了该区上奥陶统五峰组—下志留统龙马溪组页岩气储层的非均质性及其主控因素。研究结果表明:(1)该转换带五峰组—龙马溪组页岩气储层非均质性主要表现在骨架非均质性和孔隙非均质性两个方面,优质页岩层段与上覆页岩段在脆性矿物含量、黏土矿物含量、有机质丰度、孔隙度等方面差异较大,具有较强的纵向非均质性;(2)储层发育有机质孔、脆性矿物孔、裂缝等多种储集空间类型,并且孔隙在形态、分布、孔径、结构特征方面的差异明显,具有较强的微观非均质性;(3)页岩岩石物理参数泊松比、杨氏模量也相应表现出较大的差异;(4)页岩气储层非均质性的主控因素是沉积环境差异导致的岩石骨架变化,构造缝及其多向性增强了储层的非均质性,成岩作用进一步改变了骨架矿物和有机质的含量,对孔隙类型及结构产生影响,进一步加剧了页岩储层的非均质性。结论认为,龙一下亚段应为该区下一步页岩气开发的首选目的层系,平面上以远离构造相对活动带和深大断裂为宜,区块上优选南川区块。     

四川盆地德阳—武胜拉张槽西段构造—沉积特征及勘探领域

基于前人的认识和勘探成果,结合川西地区地球物理及地表地质资料,研究分析了四川盆地德阳—武胜拉张槽(西段)的结构及沉积充填特征,探讨了有利勘探领域及方向。德阳—武胜拉张槽是四川盆地晚二叠世长兴期在弱伸展背景下形成的北西向张性构造单元,具有两侧地层厚、中间地层薄的槽状结构特征。德阳—武胜拉张槽两侧边缘(台缘带)发育生物礁、生屑滩等高能相带沉积,有利于储层发育;槽中央发育较深水—深水环境下的微晶灰岩、硅质泥岩、碳质泥岩、页岩等岩性组合,是有利的烃源岩;其西段龙宝梁三维工区内沿着北西向台缘带发育带状生物礁,与下伏龙潭组等烃源岩及槽内长兴组泥页岩构成"下生上储"、"旁生侧储"源—储组合。该拉张槽边缘相带是油气的潜在勘探领域,龙宝梁地区是近期勘探的有利目标。     

Geochemical characteristics of the Permian marine mudstone and constraints on its provenance and paleoenvironment in the Fenghai area, Fujian Province, southeastern China

Permian marine strata have gradually become a research focus in the world. The marine strata of the Late Permian Dalong Formation (P₃d) in the Fenghai area, Fujian Province, have become more and more important as their geochemical characteristics record important geological information and are a good indicator for recovering and reconstructing the paleosedimentary environments and tectonic attributes. The major elements, trace elements and rare earth elements were analyzed by XRF and ICP-MS, respectively. Based on the results of detailed field geological surveys, profile measurements as well as typical sample collection, the tectonic setting and provenance of Permian marine mudstone were comprehensively discussed. The results showed that the Dalong Formation (P₃d) was deposited in an active continental margin tectonic environment as revealed by the relation between Fe₂O₃ + MgO and TiO₂ and Al₂O₃/SiO₂. The fingerprint characteristics of Mn, Fe, Co, Ni and REE and the ratio of U/Th, V/Cr, Sr/Ba, (La/Yb)_N and V/(V + Ni) indicated that the sedimentary provenance was mainly derived from potassium feldspar, followed by muscovite. Sedimentary water bodies showed a gradually decreasing depositional rate trend, water depth gradually shallowing and paleo-salinity and productivity gradually increasing. Moreover, since transient delamination occurred during sedimentary processes, sedimentary water bodies showed obvious neritic characteristics. It was consistent with the results revealed by lithological and geochemical characteristics. Calcareous mudstone and siltstone transitioned into fine sandstone from bottom to top, indicating paleo-water bodies became shallow. The research results provided good reference and guidance for understanding Permian paleo-sedimentary environments and tectonic attributes of the Yong’an area, Fujian Province, southeastern China.     

中中新世以来南海南部前隆的迁移:来自北康盆地的证据

利用二维地震资料探讨南海南部北康前隆的迁移现象及其对形成油气圈闭的影响。在南沙海域，早中新世不整合（EMU）是一个区域性不整合面，EMU之上的地层可以简单归结为披覆层系和水平层系。披覆层系直接覆盖在EMU上，具有连续薄层的平行地震反射特征，向南东方向加厚，属于悬浮沉积；而水平层系同期充填在低凹处，不断上超和覆盖早期的披覆层系，厚层状，呈不连续或弱反射特征，属于浊积物与悬浮物的混合沉积。通过上超反射终止的迁移和披覆层系的加厚两个特征判断，中中新世以来北康前隆在向上隆升的同时不断向南东方向迁移，反映了南沙海域减薄的陆壳有一个强烈挠曲和均衡反弹过程。前隆的迁移留下了一系列的古潜山，披覆层系和水平层系是很好的盖层，有利于圈闭的形成。     

Trade-Off between Efficiency and Effectiveness: A Late Fusion Multi-View Clustering Algorithm

Late fusion multi-view clustering (LFMVC) algorithms aim to integrate the base partition of each single view into a consensus partition. Base partitions can be obtained by performing kernel k-means clustering on all views. This type of method is not only computationally efficient, but also more accurate than multiple kernel k-means, and is thus widely used in the multi-view clustering context. LFMVC improves computational efficiency to the extent that the computational complexity of each iteration is reduced from O(n³) to O(n) (where n is the number of samples). However, LFMVC also limits the search space of the optimal solution, meaning that the clustering results obtained are not ideal. Accordingly, in order to obtain more information from each base partition and thus improve the clustering performance, we propose a new late fusion multi-view clustering algorithm with a computational complexity of O(n²). Experiments on several commonly used datasets demonstrate that the proposed algorithm can reach quickly convergence. Moreover, compared with other late fusion algorithms with computational complexity of O(n), the actual time consumption of the proposed algorithm does not significantly increase. At the same time, comparisons with several other state-of-the-art algorithms reveal that the proposed algorithm also obtains the best clustering performance.