Deepwater and Deep Layers： the Strategic Choices for China＇s Oil and Gas Resources Development

On December 2, 2017, the 2nd Seminar on the Development Strategy of China＇s Oil and Gas Resources was held in Beijing. This seminar was hosted by the Strategic Research Center for Oil and Gas Resources, Ministry of Land （MLR） and Resources and sponsored by both the CNOOC Exploration Department and the School of Ocean and Earth Sciences of Tongji University. With the theme of ＂deepwater and deep-layer oil and gas resources and development strategy＂,

China Offshore Oil Industry and Foreign Investment

The history of China's offshore oil industry can be traced back to late 1950's when geophysical surveys started in limited offshore areas.Then,in 1960's and 1970's,a few exploratory wells scattered from north down to south were drilled resulting in a number of discoveries with the total proven oil in place being merely 40 million tons.In fact,the China's offshore oil industry in a real sence did not emerge on the horizon until early 1980's when China opened its door to outside world and the China National Offshore Oil Corporation(CNOOC)was born.

Modeling underwater transport of oil spilled from deepwater area in the South China Sea

Based on a Lagrangian integral technique and Lagrangian particle-tracking technique,a numerical model was developed to simulate the underwater transport of oil from a deepwater spill. This model comprises two submodels: a plume dynamics model and an advection-diffusion model. The former is used to simulate the stages dominated by the initial jet momentum and plume buoyancy of the spilled oil,while the latter is used to simulate the stage dominated by the ambient current and turbulence. The model validity was verified through comparisons of the model predictions with experimental data from several laboratory flume experiments and a field experiment. To demonstrate the capability of the model further,it was applied to the simulation of a hypothetical oil spill occurring at the seabed of a deepwater oil/gas field in the South China Sea. The results of the simulation would be useful for contingency planning with regard to the emergency response to an underwater oil spill.

An Installation System of Deepwater Risers by An S-Lay Vessel

Along with the consumption increase of the petroleum products, more countries have transferred their attentions to the offshore fields, especially the deepwater oil and gas reserves. For deepwater exploitation, the risers must be installed to act as the conduits connecting surface platforms to subsea facilities. In this paper, the typical risers sorted by different classes are introduced, and the correspondent installation methods are presented. By investigating the recent projects performed in the deepwater hot spots, and combining the challenges of HYSY20 l for riser installation, a lifting device developed for assisting riser installation is proposed and detailed to satisfy the installation of deepwater risers in the LW3-1 Gas Field of 1500 m in the South China Sea. Tests on both the functions and performances of such a new system exhibit the satisfaction of meeting all challenging requirements of HYSY201 for application to riser installation in waters up to a depth of 3000 m in the South China Sea.

Strategic Thinking on Shallow-water Oil and Gas Exploration in Offshore China

The oil and gas exploration in offshore China has made great achievements,and as the important areas of offshore exploration,the shallow waters contribute most of the oil and gas reserves and production.However,the available area for exploration is diminishing and the cost of exploration is rising.The field changes and ever increasing difficulties of exploration bring new challenges technically and economically.Therefore,for effective exploration of shallow-water oil and gas in offshore China,it is necessary to center on the general requirements of becoming a powerful marine country and the ideas of value exploration,initiate key research projects in the fields of China's offshore stratigraphic-lithologic reserves,Paleogene reserves,buried-hill reserves,high temperature and pressure reserves and hydrocarbon-rich sags,and form geological theories and explorative technologies of large and medium size oil and gas field in offshore China.The measures regarding the challenges include:(1) Innovating theoretical understanding and optimizing new exploration fields,(2) developing technical capabilities and improving the success rate of exploration,and(3) enhancing management level and deepening value exploration.

Reservoir forming conditions and key exploration technologies of Lingshui 17-2 giant gas field in deepwater area of Qiongdongnan Basin

On September 15,2014,China National Offshore Oil Co.,Ltd announced that a high production of oil and gas flow of 1.6
106 m3/d was obtained in Well LS17-2-1 in deepwater area in northern South China Sea,which is the first great oil and gas discovery for self-run deepwater exploration in China sea areas,and a strategic breakthrough was made in natural gas exploration in deepwater area of Lingshui sag in Qiongdongnan Basin.Under the combined action of climax of international deepwater exploration,high oil prices,national demands of China,practical needs of exploration,breakthroughs in seismic exploration and testing technologies,innovations in geological cognition and breakthroughs in deepwater operation equipment,Lingshui 17-2 gas field is discovered.Among these factors,the innovation in reservoir forming geological cognition directly promotes the discovery.The quality of seismic data in the early time is poor,so key reservoir forming conditions such as effective source rocks,high quality reservoirs and oil-gas migration pathways are unable to be ascertained;with support of new seismic acquisition and processing technology,some researches show that Lingshui sag is a successive large and deep sag with an area of 5000 km2 and the maximum thickness of Cenozoic stratum of 13 km.In the Early Oligocene,the Lingshui sag was a semi-closed delta-estuarine environment,where the coalmeasure and marine mudstones in Lower Oligocene Yacheng Formation were developed.The Lingshui sag is a sag with high temperature,and the bottom temperature of source rocks in Yacheng Formation can exceed 250C,but the simulation experiment of hydrocarbon generation at high temperature indicates that the main part of this set of source rock is still in the gas-generation window,with resources of nearly 1 trillion cubic meters,so the Lingshui sag is a hydrocarbon-rich generation sag.In the Neogene,the axial canyon channel from the Thu Bon River in Vietnam passed through the Lingshui sag,and five stages of secondary channels were developed in the axial canyon channel,where four types of reservoirs with excellent physical properties including the axial sand,lateral accretion sand,natural levee sand as well as erosion residual sand were developed,and lithologic traps or structural-lithologic traps were formed.The diapiric zone in the southern Lingshui sag connects deep source rocks in Yacheng Formation and shallow sandstones in the channels,and the migration pattern of natural gas is a T-type migration pattern,in other words,the natural gas generated from Yacheng Formation migrates vertically to the interior of the channel sandbody,and then migrates laterally in the channel reservoirs and forms the reservoirs.Innovations of geophysical exploration technologies for complicated geological conditions of deepwater areas are made,such as the detuning comprehensive quantitative amplitude hydrocarbon detection technology,which greatly improves the success rate of deepwater exploration;key technologies of deepwater safety exploratory well testing represented by the platform-dragged riser displacement technology are developed,which greatly reduces the drilling test cost.The above key exploration technologies provide a strong guarantee for the efficient exploration and development of Lingshui gas field.

CNOOC Discovers Deepwater Gas Field in South China Sea

China National Offshore Oil Corporation (CNOOC) andHusky Oil China Limited have made a new deepwater gasdiscovery,Liuhua (LH) 34-2,which is the second deepwatergas discovery in the Pearl River Mouth Basin in the easternSouth China Sea following Liwan (LW) 3-1 in this area.CNOOC Limited said on December 9th,2009.The Liuhua 34-2-1 well has ability of producing 55 millioncubic feet of natural gas per day.

南海东部油田浅储层随钻测压取样技术及应用

针对南海东部浅层疏松砂岩地层的特征,优选了测压取样工具,提出了在作业前优化作业方案,在测压取样过程中,优化泵抽速度,及时判断砂堵并有效解堵等,大大提高了测压取样作业的成功率。

国外Spar平台研究现状及中国南海应用前景分析

Spar平台是1种新型深水平台,其吃水深,水线面积小,运动稳定性好,适合500～3 000 m水深的油气开发工程。文中详细介绍国外Spar平台及其关键技术研究和开发现状,分析中国南海深水油气开发的应用前景及南海环境条件下的新概念Spar平台。

西非深水油气田开发状况及其发展趋势

西非深水海域油气资源丰富、开发潜力巨大,是世界上公认的海上油气田最具开发前景的地区。由于众多石油公司参与开发,西非深水油气田的开发模式呈现多样性。文章分析研究了西非现有深水油气田的开发模式、相关技术及发展趋势,为西非深水油气田的开发提供了一定的参考依据。

中国近海油气田区域开发战略思考

总结了我国近海油气田开发从大型油田独立开发-油田群联合开发-体系性开发的历程,分析了目前我国近海油气田开发面临的挑战,提出了区域开发模式,并阐述了区域开发的定义、区域划分原则和区域开发总目标,指出了我国近海油气田区域开发的重要性、可行性,以及区域开发工作的重点。

中国油气田开发现状、面临的挑战和技术发展方向

回顾了我国油气田开发所走过的不平凡光辉历程,简要叙述了我国油气田的储层地质特点、主要类型和已形成的技术系列,揭示了近年来所面临的严峻挑战,比较详细地阐述了应对这些挑战的技术对策和开发好高含水、低渗透、稠油、海洋等主要类型油田和各种复杂气田的技术发展方向。

发展海工设备制造,走向世界海洋石油市场

近年来,深海油气勘探开发发展迅速,在2000~2005年全球新增油气储量中,陆上、浅水和深水分别占28%、31%和41%。与此相应,该领域的投资也持续快速增长,据预测,2012年全球海域作业支出将达到3610亿美元,比2007年增长42.1%,其中深水增幅约74%。在影响海上油气发展的诸多因素中,有两个问题最为业内人士所关注。一是海上油气发展需要大量的设备,而所涉及的种类众多的设备和技术必须形成智能化的配套体系;二是要有能胜任海上石油运作实力强大的团队,它不仅拥有投资和抗风险的实力,也要具有一流的技术和管理人才团队。近两年我国海工设备制造已进入深水领域,中国各大造船厂与各大石油公司的海工基地一起,组成了我国正蓬勃兴起的海洋石油装备制造队伍。但同时在这个领域也存在着专业化程度和关键设备国产化程度偏低,深水、超深水配套能力不足等问题。我国应将海上石油设备研制作为走向制造强国的＂抓手＂之一,统一规划,形成协同发展的合力。在拥有了适用于深水的设备并形成初步配套后,就可大踏步走向世界海洋石油市场,在实践中进一步提高设备制造的水平和配套的完整性。此外,我国在南海应更加积极主动地进行勘探开发活动,以深水勘探打破南海油气停滞、被动的局面。

中国近海油气勘探进展

近年来,中国近海的油气勘探坚持以寻找大中型油气田为指导思想,以区域研究为基础,以科学合理部署为保证,针对中国近海独特的油气地质特征,通过创新认识和技术进步,坚持走高效勘探之路,取得了丰硕成果,新发现储量屡创历史新高,步入了历史上最好时期。然而,随着勘探程度的提高和勘探领域的拓展,中国近海油气勘探也面临越来越多的挑战。

中国近海油气勘探的回顾与思考

在回顾中国近海油气勘探历程的基础上,介绍了中国近海油气勘探近年来取得的主要成果,总结了近年来中国近海油气勘探的成功做法和经验,探讨了如何在中国近海走油气勘探的可持续发展之路。

海上欠饱和稠油油田原油降黏方式探讨

根据海上油田开发的特殊要求 ,通过理论计算 ,对比分析了用加热降黏法和加气降黏法进行稠油开采的差异 ,探讨了欠饱和稠油油田用天然气回注地层降黏的可行性 ,认为在原始地层压力条件下 ,仅向地层原油中补充溶解气油比是原始溶解气油比的 0 .5～ 1.5倍的天然气 ,就可以有效地降低原油黏度 ,提高采收率。采用加气降黏法比加热降黏法具有工程规模小、建设周期短、耗能少、投资少的优点 ,因此更具实用价值。

中国海上油气形势及展望

经过20余年的开发,海上油、气产量己分别占全国20.4%、8.7%。南海北部石油产量在上世纪90年代上升最快并成为主产区,但1997年后呈波状快速下降。本世纪初渤海产量快速上升并成为主产区。2011年海上产量已出现降势,可能是今后转为相对稳产和下降的信号。为维持海上油气稳产/增产需大力进行新区新领域的战略接替。新区的现实接替区是南黄海,特别是南海北部陆坡深水—超深水区。新领域为南海北部到东海的中生界。

深水大型半潜式天然气生产平台风险管理

位于南海北部的陵水17-2气田半潜式天然气生产平台是国内首个1500 m水深、立柱内大容量储存凝析油的半潜式生产平台,为了识别其各系统的潜在风险并进行风险管理,利用HAZOP、SIL和基于熵权的贝叶斯网络方法,结合专家的经验,对该平台的常规和特有风险进行了分析评价。研究方法和步骤包括:①确定事件与事故的因果关系,建立贝叶斯网络;②进行事故致因分析,确定最大事故致因链;③开展敏感性分析,找出对事故发生概率影响最大的事件,为风险防控提供重要依据;④依据风险识别与分析结果,针对平台各子系统提出相应的风险防控建议。由此建立了该半潜式平台的风险管理流程,将平台划分为系泊、立管、平台上部(气体接收和分离、气体压缩、气体脱水和燃气、生产水、凝析油处理、排水管和火焰)、船体设施、生活区以及货物装卸区等11个区域,针对每一个区域进行HAZID分析,识别出平台火灾爆炸、烟气扩散、船舶碰撞、落物、逃生撤离救生、化学品泄漏以及凝析油储存和外输等风险源,并给出了主要风险的应对措施。结论认为,该项研究成果对于我国未来深水油气项目的风险管理具有重要的参考价值。