Interactive design exploration for constrained meshes

In architectural design, surface shapes are commonly subject to geometric constraints imposed by material, fabrication or assembly. Rationalization algorithms can convert a freeform design into a form feasible for production, but often require design modifications that might not comply with the design intent. In addition, they only offer limited support for exploring alternative feasible shapes, due to the high complexity of the optimization algorithm.We address these shortcomings and present a computational framework for interactive shape exploration of discrete geometric structures in the context of freeform architectural design. Our method is formulated as a mesh optimization subject to shape constraints. Our formulation can enforce soft constraints and hard constraints at the same time, and handles equality constraints and inequality constraints in a unified way. We propose a novel numerical solver that splits the optimization into a sequence of simple subproblems that can be solved efficiently and accurately.Based on this algorithm, we develop a system that allows the user to explore designs satisfying geometric constraints. Our system offers full control over the exploration process, by providing direct access to the specification of the design space. At the same time, the complexity of the underlying optimization is hidden from the user, who communicates with the system through intuitive interfaces.     

川西彭州地区雷口坡组潮坪相薄储层辨识机理研究

川西彭州地区三叠系雷口坡组雷四上亚段潮坪相薄储层识别难度极大。围绕如何从复合地震强反射中区分并识别上、下两套储层面临的地球物理难题,采用先“分”后“合”的研究思路,基于实际地层结构及不同储层叠加样式建立正演模型,利用全波场波动方程正演模拟技术,剖析了不同主频条件下薄储层的地震响应特征,通过波形差异化分析,从复合地震响应中“剥离”出了两套储层所引起的地震响应特征及变化规律,明确了两套储层在不同频带下的地震识别标志和识别方法,为该区强反射界面干扰下两套薄互层储层辨识机理分析及精准预测奠定了基础。基于不同频带下薄储层辨识机理的分析结果,定性预测了薄储层平面展布,提出了深层潮坪相薄储层识别和预测难题的解决方案,为该区地震资料品质评价、面向薄储层的地震采集技术设计、地震资料处理及薄储层预测提供了依据和指导。     

Data sharing mechanism of various mineral resources based on blockchain

Basins with various mineral resources coexisting and enriching often occupy an important strategic position. The exploration of various mineral resources is repetitive at present due to unshared data and imperfect management mechanism. This situation greatly increases the cost of energy exploitation in the country. Traditional data-sharing mode has several disadvantages, such as high cost, difficulty in confirming the right of data, and lack of incentive mechanism, which make achieving real data sharing difficult. In this paper, we propose a data-sharing mechanism based on blockchain and provide implementation suggestions and technical key points. Compared with traditional data-sharing methods, the proposed data-sharing mechanism can realize data sharing, ensure data quality, and protect intellectual property. Moreover, key points in the construction are stated in the case study section to verify the feasibility of the data-sharing system based on blockchain proposed in this paper.     

电磁精细探测法在隐伏型导水地质裂缝勘探中的应用

针对传统隐伏型导水地质裂缝勘探方法存在勘测精度较差的问题,提出电磁精细探测法探析隐伏型导水地质裂缝。依照屏蔽系数、实测场强和理论场强数据绘制综合曲线图,通过该图获取隐伏型导水地质裂缝所处位置几何阴影范围,采用层析成像法得到网格化的工作面,获取隐伏型导水地质图像。通过图像直接观测隐伏型导水地质工作面裂缝所处位置,在此基础上,观测四个电磁场分量,采用正交电磁场分量计算介质视电阻率,依据计算视电阻率数值和视电阻率分布状态研究裂缝发育情况和裂缝富水程度。结果表明:采用该方法能较为精准地获取隐伏型导水地质裂缝位置。通过裂缝位置进一步检测出隐伏型导水地质裂缝最大发育高度为63.5 m。当视电阻数值不断增加时,隐伏型导水地质裂缝和裂缝富水性逐渐减小,与实际情况较为相符,说明该种方法探析效果较好。     

气烟囱效应——礁滩相岩性气藏的典型地震响应特征

品质良好的地震剖面上出现的地震模糊带称为气烟囱，发现和识别气烟囱是寻找大型气藏的有效方法。四川盆地东北部长兴组气藏是礁滩相岩性气藏，礁、滩作为一个独立的岩性体，与周围的地层、岩性结构差异较大，由此在构造应力场中形成力学尖点，从而产生气烟囱效应。已知的黄龙场、普光等气田，其气烟囱普遍存在。点礁通常形成下方的气烟囱，台缘礁通常在上方形成气烟囱；礁滩相在构造运动中控制了断层的发育过程，凸起的礁滩相上方可能发育对冲断层；斜坡较陡的台缘礁可能发育叠置的逆冲断层；礁、滩两侧边缘的断层一般都比较发育。断层发育加强了气烟囱效应。模拟试验验证了地震剖面解释结果。根据气烟囱地震相特征，预测黑池梁存在一个大型气藏。     

CYLINDRICAL AND CONICAL FOLD GEOMETRIES IN THE CANTARELL STRUCTURE, SOUTHERN GULF OF MEXICO: IMPLICATIONS FOR HYDROCARBON EXPLORATION

The NW‐SE trending Cantarell structure in the Gulf of Campeche hosts the largest oilfield in Mexico. The oil occurs predominantly in latest Cretaceous – earliest Tertiary breccias with subsidiary reserves in Upper Jurassic (Oxfordian and Kimmeridgian) and Lower Cretaceous oolitic and partially dolomitized limestones, dolomites and shaly limestones. Cantarell has been interpreted both as a fold‐and‐thrust zone and as a dextral transpressional structure. Analysis of structure contours at 100m intervals, on the tops of the Tertiary breccia and the Kimmeridgian (Upper Jurassic) dolomite, indicates that the structure is an upright cylindrical fold with gently plunging conical terminations; there is also a conical portion in the central part of the structure. The axes of the central, NW and SE cones are subvertical. This geometry indicates that the two fold terminations and the central cone are aprons rather than points, with the NW and central cone axes intersecting the cylindrical fold axis at the point where the geometry switches from conical to cylindrical. The apical angle (i.e. the angle between the fold and cone axes) varies as follows: (i) in the NW cone, it is ～70° in the breccia and ～76° in the Kimmeridgian dolomite; (ii) in the central cone, it is ～77° in the breccia and ～73° in the Kimmeridgian dolomite; and (iii) in the SE cone, it is ～64° in the breccia and ～57° in the Kimmeridgian dolomite. This indicates that whereas the fold opens with depth in the NW cone, it tightens with depth in the central and SE cones. Assuming a parallel fold geometry, these apical angles indicate an increase in volume in the NW cone (i.e. larger hydrocarbon reservoirs), compared to the central and SE cones. Theoretical considerations indicate that the curvature increases dramatically towards the point of the cone. In the case of the Cantarell structure, the apices of the cones are located at the conical‐cylindrical fold junctions, where the highest curvature may have resulted in a higher degree of fracturing. The coincidence of maximum curvature and the intersection of the conical and cylindrical fold axes in the fold culminations with porous and permeable reservoir rocks may have made these locations favourable for the accumulation of hydrocarbons.     

四川盆地上三叠统划分对比研究

四川盆地上三叠统对比长期存在混乱，给盆地整体评价带来困难。通过岩石地层、地震地层、事件地层及高分辨率旋回地层等多种方法讨论了须家河组与香溪群各岩性段的对比关系，得出了全盆地上三叠统的对比关系；指出须四段底可近似看成等时界面；须家河组下部地层自西向东、向南逐层超覆在雷口坡组之上，上部地层在盆地西北部自东南向西北方向剥蚀层位渐次变老。文章建议四川盆地上三叠统废除“香溪群”，统一使用“须家河组”，以利于对全盆地上三叠统进行油气资源整体评价与深化研究。     

地震属性解释技术的研究及确定性分析

随着油气勘探开发的不断发展，储层预测、属性分析等技术得到了广泛的应用，在生产中取得了较好的效果。但地震属性的概念，分类方法，地震属性之间、地震属性与储层参数之间的相互关系仍较模糊，各种地震属性解释方法虽然种类繁多，但缺乏系统的研究，这使得地震属性在应用中存在较大的不确定性。文章通过系统研究地震属性的概念、储层地震响应的基本特征，提出了地震响应的核心是反映地震波在介质传播过程中的能量变化，所有能引起地震能量发生变化的介质的不均质性均可导致地震属性的变化，由此提出了一种新的地震属性分类方法，并认为大部分地震属性只是基本属性在不同域中的不同表现形式。在分析现有地震解释技术的基础上，提出了对地震属性解释的新认识，强调了地震属性对地层岩性油气藏勘探的重要性，对属性间的关系及地震属性解释技术的确定性进行了研究，提出了岩性油气藏地震解释的工作流程及对地震资料采集和处理的要求。     

多介质立体取样及在北黄海油气化探中的应用

由于不同环境条件下,不同化探测试指标受到不同的因素干扰,所以不同介质样品的应用条件存在一定的差异。针对不同介质样品特点,分别采集海底沉积物、底部海水和低空大气3种介质样品,并采用在海底沉积物柱状样不同深度部位取样的立体取样方法,通过多指标综合分析,对不同介质和深度样品的多项化探指标互相进行了验证和补充,可以抑制干扰因素的影响,为油气资源远景评价提供依据。运用该方法在北黄海盆地油气勘查中进行初步尝试,并据此划分了三级化探异常区,提出了有利的含油气远景区,均与已知油气区和区域地质分析的结果相符合,取得了很好的效果。      

营尔凹陷下白垩统油气勘探应避开高压水层

营尔凹陷下白垩统(K₁₎存在下沟组和赤金堡组2套源岩，目前它们已到成熟阶段。凹陷东侧长沙岭构造在下白垩统下沟组和赤金堡组储层中也发现油藏，但主要分布在高压水层的顶部及下部，而高压水层段存在良好的储层，并未发现油气。文章根据高压水层段的储层荧光特征，通过储层烃与源岩的对比，分析了下白垩统高压水层对油气运移的影响。研究结果表明：高压水层段，储层荧光弱，储层抽提物特征既不同于赤赤金堡组源岩，也不同于下构组源岩，为就近捕获的产物；高压水层未发生大规模的油气运移，其形成时间早于油气运移的时间。建议该区油气勘探目标的选择应避开高压水层，选择凹陷附近的圈闭、高压水层以下的层位。