海缆路由探测中浅地层剖面仪的现状及应用

浅地层剖面仪以其高效和经济性成为了海底地质情况和海缆路由的有力勘查手段。本文在介绍浅地层剖面仪工作原理及其技术发展历程的基础上,以实例展现了浅地层剖面仪的应用效果;通过调研阐述了国内外浅地层剖面仪的发展现状,着重论述了国外各大厂家的商品化Chirp和SES型浅地层剖面仪及其关键技术指标,对浅地层剖面仪在海缆探测中存在的...     

基于MIP-CPT技术的海底浅层气探测方法——以东海舟山海域为例

国际上MIP-CPT技术在陆域环境污染监测领域得到了较成功的应用。为了准确识别海底浅层气,避免其对海洋开发的影响,采用MIP-CPT技术,辅以其他多种地球物理探测方法,在东海舟山海域进行了海上试验。基于得到的MIP数据识别了测试海域海底面以下30 m内的游离气和溶解甲烷,将典型孔位的FID信号与同位置的浅地层剖面进行对比,基本符合地球物理勘察的结果;结合同时得到的多项CPTU数据对MIP数据进一步分析发现测试海域的浅层气主要来源于较深部地层,并得到了多道地震勘探数据的旁证。研究表明相对于传统浅层气探测手段,MIP-CPT技术具有快捷性、直观性和多数据的优势,这种技术很适合研究海底浅层气的成因机制。     

深拖系统在南海深水工程勘察中的应用

利用DT1深拖系统搭载EM2000多波束测深系统、EdgeTech侧扫声呐及浅地层剖面系统等设备在南海北部陆坡区域进行了大范围的深入调查,获取了调查区丰富的地形、地貌及浅地层的数据。在对定位数据滤波的基础上,借助Caris、Triton和KingdomSuite等软件分别对上述数据信息进行了高保真、精细化处理和多模式展示。资料处理成果清晰地揭示了调查区的滑坡、陡坡、凹沟等特殊地形地貌的特征,为评价调查区的工程地质条件提供了丰富的信息。本文探讨并总结了历次深拖调查作业所获得的技术经验,可为深水海域的类似调查提供参考和借鉴。     

Evaluation of the seafloor structural setting of Alamein New City offshore area,Egypt

The Alamein New City is one of the newly established capital cities in Egypt. The study of the offshore extension is important to define the morpho-sedimentary seafloor features and evaluate the structure of the seafloor, sand resources, and the quantities of sediments that are responsible for beach renourishment. To achieve the purpose of the study, the marine acoustic geophysical techniques (MBES, SSS, and SBP) with video-camera attached in the ROV as a ground truth tool, were used. That has proven to be extremely powerful techniques in coastal applications.The integration of the marine geophysical data obtained from the bathymetric, shallow seismic surveys, and the validity of these data that was confirmed by SSS backscatter sonograph, in addition, the images obtained by using the ROV, divided the study area into three main zones. The southern zone (Z1) was rugged, which coincided with sandy mounds in the area, and has gradual backscatter strength from high to moderate with the direction of the prevailing current describing the rugosity of sand ripple. This zone has characterized by the thickest layer of sediment in the study area. Whereas the middle zone (Z2) showed the highest values of rugosity due to the slope where the ridge exists and has complex backscatter strength with finer thick of sediment. The northern zone (Z3) was characterized mostly by intermediate rugosity and gradual backscatter strength from high to moderate aligned with the direction of the current, describing the rugosity of sand ripple. The northern zone has the second thickest layer of sediment.The gentle sloping of the seafloor with the existence of the mounds and the submerged ridge are allowing the waves to break and scatter their energy provide natural protection for the beaches of Alamein New City.     

Distinguish seabed objects utilizing different marine acoustic techniques

The marine acoustic techniques are powerful tools to investigate and identify the seabed objects by applying different processing and interpretation steps. Two types of marine acoustic imaging techniques used in this study; Side Scan Sonar (SSS) that mapping seabed features and identifies the objects on it, and Sub-Bottom Profiling (SBP) that providing information about sediment thicknesses and stratigraphic structure. The integration between these two marine acoustic techniques, as well as, ground truth data obtained from an underwater camera, was used to distinguish seabed objects; coastal boulder accumulations that are documented along the western Mediterranean coast of Egypt. The study and analysis of the collected data demonstrated that: the combination between side scan sonar, chirp sub-bottom profiling systems, and ROV images can successfully distinguish different types of objects. Generally, objects observed from SSS are indicated in the SBP as weak backscatter curves. The case study results, from analysis of SBP with ROV image to the object detected by SSS utilized three objects making a shadow in SSS seabed: boulder, hard substrate, and seagrass. The integration of these techniques resulting specifies the location of the geo-hazards area.     

油泉子地区表层结构调查方法

柴达木盆地油泉子地区因地表干燥层巨厚,低降速带厚度大,使用常规浅层调查方法难以确定合适的激发层位。针对上述问题在本区开展了录井岩样含水量调查、电测井及高密度电阻率法等研究工作,以配合地震微测井工作。通过采用上述方法对两条相交试验测线的表层结构开展联合调查,结果发现在地表以下35m深度范围内仍然可以找到1-2个井段为高含水量及低电阻率值部位,适宜地震勘探激发。这套表层联合调查方法为地震与非地震方法结合提供了一条新途径。     

舟山东极岛东侧海底浅层气特征

利用声学剖面仪对舟山东极岛东侧海域进行探测,发现该区存在较为明显的浅层气特征:一是海水中存在云雾状反射;二是侧扫声纳海底影像显示海底存在有三个海底凹陷;三是声学浅地层反射剖面中存在声波反射异常现象,主要表现为反射剖面的声学幕和声学空白。静力触探(CPT)探测显示该区沉积物中有溶解甲烷。经过分析,海水中的云雾状反射是浅层气作用形成的。海底凹陷是由浅层气引起的沉积物不均匀下陷的结果。     

Geoelectrical resistivity mapping and characterization of bituminous sands at some parts of Eastern Dahomey Basin,SW Nigeria

Predicting the variability and subsurface distribution of bituminous sand deposits rely significantly on integrating geophysical techniques such as electrical resistivity mapping with borehole information. While several studies have been conducted to characterize the bitumen-rich sequence of the sedimentary terrain of the study area, there are no or few studies documenting the subsurface architecture of bituminous sands in the transition zones in the study area. This study utilized the integration of 2D electrical resistivity mapping and borehole lithology logs to delineate and characterize bituminous sands in the study area to provide insights into the electrical resistivity signature of bituminous sand deposits within the transition zone in Ondo state, SW Nigeria. Two boreholes (BHI and BH2) and 2D electrical resistivity mapping using dipole–dipole array along five traverses were used for the investigation. A systematic and data-based approach was employed for the mapping of the deposits. The 2D electrical resistivity survey acquisition was carried out on traverses oriented north–south in the direction perpendicular to the sedimentary strike to effectively map the bituminous deposits. The results obtained from the approach employed indicated a maximum of three to four geoelectric layers delineated within the study area. This includes the topsoil, the upper X-horizon, mudstone, and lower Y-horizon. The upper/shallow bituminous sands in the X-horizon, as well as the deeper bituminous sands in the Y-horizon sands, are characterized by a very high resistivity range of about 1000 to about 100,000 Ωm. Findings from this study reveal that the resistivity of bituminous sands in the area is generally high in contrast to the low resistivity signature observed in the sedimentary parts of the area. The results obtained from this study would serve as a means to guide future exploration studies within transition zones in Eastern Dahomey Basin, SW Nigeria.     

地震照明分析技术在深海地震数据采集设计中的应用

中国南海北部陆缘深水海域是形成大型油气区的有利区域。但由于该区水深急剧变化,峡谷纵横,构成了海底崎岖的地形地貌带,给该区的油气勘探带来了困难。本文利用高斯射线束地震波正演模拟方法,研究了南海白云凹陷深水崎岖海底区地震波对地下目的层的激发照明以及检波器接收照明能量的分布特征。针对不同接收缆数、不同排列长度及不同激发方向对海底崎岖界面和深部目的层的激发与接收照明能量的模拟分析,初步认识崎岖海底和下伏目的层地震波能量的分布特征,以及不同观测系统参数对地震采集能量的影响程度,为南海崎岖深海区地震采集参数设计提供了依据。     

基于CMP直线分布的不规则观测系统设计方法研究

我国南方海相碳酸盐岩油气区及西部前陆盆地边缘探区,均面临着地表起伏剧烈和地下构造高陡的双复杂地震勘探问题。为了准确勘查地下构造形态,野外地震采集中应尽可能降低起伏地表的复杂性及优选最佳的激发参数,从而获得高信噪比的地震单炮记录。在保证沟谷平坦区有利激发的前提下,通过最优化反演进行弯曲接收排列的设计,使得最终得到的二维地震剖面具有直线反射面元的特征,通过加入局部宽线的采集措施,使弯线地震采集的每个中心面元的覆盖次数和炮检距能够均匀分布。进行了四川盆地东北部镇巴地区复杂山地不规则观测系统的设计和属性分析,证明了基于CMP直线分布的不规则观测系统设计方法具有很好的实际应用价值。     

复杂山地地震采集技术在库车坳陷的应用

塔里木盆地库车坳陷的地震资料受到复杂地表结构和地腹地质条件的影响,普遍存在着信噪比低、剖面品质不高的问题,制约了油气勘探开发的进程。为此,在库车坳陷DK二维地震攻关测线施工中,以宽线观测系统、大基距组合接收(巨厚黄土堆积带采用9串检波器面积组合接收,老岩层出露的复杂山体区采用3串检波器"三"字形组合接收)为核心采集技术,开展详细表层调查,利用地震工程遥感技术选择合理的激发点和接收点,同时增加目的层的覆盖次数,强化激发和接收条件,从而提高了单炮记录的信噪比,改善了地震剖面的品质,为库车坳陷构造形态的重新认识提供了良好的地震资料。攻关试验的成功表明,该套技术方法在其他类似地区也具有很好的推广应用价值。     

盐穴储气库注采运行过程中的腔体形状检测

金坛储气库注采运行过程中,由于岩盐的蠕变特性,压力、温度的变化会对盐穴的形态产生影响,使盐穴发生片帮和收缩,严重的情况会影响到注采运行的安全。为了研究腔体形状的变化,评价其影响,为安全平稳的运行提供保证,也为今后国内盐穴储气库高压气腔声纳检测积累经验,给地下盐穴储气库的生产运行提供技术保障,金坛储气库对两口注采运行多年的老腔进行了检测。从高压气腔声纳检测现场施工出发,重点说明高压气腔声纳检测的详细操作程序及关键技术。这一工作在国内尚属首次。     

库车坳陷复杂山地宽线采集技术及应用效果

库车坳陷山地地震勘探受复杂地表和地下条件影响,激发和接收条件差,原始资料信噪比低,构造成像困难,影响地下构造形态认识和油气资源评价.在西秋里塔格构造带进行了宽线采集技术攻关,针对工区复杂的地震地质条件,提出了相应的技术对策.首先对宽线主要采集参数如道距、覆盖次数、最大炮检距、接收线距和激发接收参数等进行了详细论证,然后根据论证结果选择2炮3线、单线480道接收的宽线观测系统进行了资料采集.与常规二维采集相比,宽线采集能较好地解决复杂山体区资料信噪比低,浅层反射弱和中、深层成像难的问题,所获得的剖面品质有较大幅度的改善.     

多波地震资料在三湖地区油气预测中的应用

地下岩层含气时会引起地震纵波能量吸收与构造畸变问题,且单一利用纵波资料在岩性油气藏勘探中会表现出明显局限性。而转换波受地层含流体影响较小,联合应用纵波和转换波资料能有效解决单独利用纵波资料易受多重因素影响而出现的多解性问题。本文基于柴达木盆地三湖地区的高品质多波数据,从分析纵波与转换波在走时及振幅等属性上的差异入手,通过转换波合成记录标定及纵波与转换波资料匹配等,联合应用多波地震属性进行储层描述和油气预测。经实际钻探验证,本文方法在三湖地区具有较强的适用性。     

塔里木盆地库车坳陷油气勘探前景

库车坳陷为晚第三纪以来形成的前陆盆地。该区油气资源丰富,油源条件比较优越;有五套这良好的储盖组合;构造成排成带分布,构造圈闭发育;勘探领域广阔,由于该地区地面和地下条件都十分复杂,因此要加强综合研究,进一步研究油气成藏规律,并且在山地地震和高陡构造及盐下构造解释上进行攻关,同时还要解决钻井工程上克服地应力的影响和钻穿巨厚盐膏层方面所需要的新技术。     

反射和折射波联合地震勘探在JR地区的应用

JR地区地质构造复杂 ,野外采集的地震资料信噪比低。虽然在这一地区进行了多年的地震勘探方法、地震资料处理和解释的研究 ,但效果并不理想。为此 ,在该区开展了反射和折射波联合地震勘探 ,在采集方法、反射波处理方法和折射波处理方法等方面进行了试验研究 ,得到了适合于该地区的采集方式和处理手段 ,并应用采集、处理、解释一体化的工作模式 ,使资料的信噪比得到了提高 ,获得了清晰的地下构造成像     

泌阳凹陷新庄地区高密度三维地震资料采集方法研究

泌阳凹陷新庄地区地下地质构造复杂,目的层埋藏较浅,断裂发育,圈闭破碎,以往的地震资料难以满足油气勘探和开发的需要,为此,开展了高密度三维地震资料采集方法研究.首先基于正演模型对观测系统参数进行了分析和论证,然后根据论证结果和勘探目的层的实际情况设计了小道距、小炮点距、小接收线距和小激发线距的观测系统,该观测系统的特点是物理点密度较大、覆盖次数高、炮检距分布均匀.在泌阳凹陷新庄地区,采用高密度采样、连续采样和对称采样相结合的方法进行了三维地震数据采集,获得了品质良好的地震剖面,与老资料相比,新资料的信噪比和分辨率明显提高,主频由30 Hz提高到45 Hz,频带宽度拓宽了15 Hz,层间信息丰富.     

IDENTIFICATION OF SALT FEATURES IN SEISMIC DATA

Deciding on the viability of a salt deposit as a possible site for storage‐cavern solution mining requires detailed geological studies of the salt and of its confining formations. Borehole data alone can seldom deliver the information required for such a study. It can impart great detail of the subsurface but only at the actual borehole location in an area. The most practical approach to developing 3D information is to carry out a seismic survey tied in to one or more boreholes which have been logged geophysically Ideally, a high‐resolution seismic survey is needed to study relatively shallow zones of the subsurface and resolve the top and base of fairly thin beds. However in some cases it is possible to use “reach‐me‐down” seismic data acquired previously during hydrocarbon exploration. Although these data were not designed to meet the requirements of salt deposit studies, they may still be adequate for the purpose. Their use will lead to quicker and lower‐cost results than the commissioning of a full field seismic survey with concomitant processing, although in both cases a seismic interpretation would be required.     

鄂尔多斯盆地演武-三岔地区长8油层组物源分析

鄂尔多斯盆地演武-三岔地区是多油层叠合的含油富集区,但区块开发程度低,地质条件复杂,近年来油气勘探一直未能取得较大的突破。物源分析基于长8油层组三角洲沉积体系,对区内轻矿物组分、碎屑岩特征、重矿物特征、石英阴极发光及粒度特征等进行综合分析,结果表明演武-三岔地区主要受到西南部物源控制和影响,其母岩来自于西南部陇西古陆及南部秦岭的变质岩和酸性岩浆岩组合。     

渤海湾盆地东营凹陷利津洼陷西斜坡沙三下亚段沉积特征——以滨南油田滨648区为例

滨南油田构造上属渤海湾盆地东营凹陷利津洼陷西斜坡，滨648区是一个被断层复杂化、北高南低的背斜断块油藏，主力含油层系为沙河街组三段下亚段，目前处于中低含水、低采油速度开发阶段。在测井曲线标准化处理基础上，利用Direct-Art软件的多井编辑模块，在海拔垂深对比模式下进行地层划分与砂体对比，将研究区沙三下亚段划分为5个砂组、11个小层；滨648井粒度累积概率曲线、C-M图均反映出粗-中粒的高密度浊流沉积特征。研究区沙三下亚段以扇三角洲前缘亚相及前扇三角洲亚相沉积为主，进一步可划分为水下分流河道、水道间、水道砂坝、前缘席状砂以及前扇三角洲浅湖泥沉积微相；油气储集有利相带多集中在水下分流河道及水道砂坝沉积微相中。