Simulating the Effect of Hydrate Dissociation on Wellhead Stability During Oil and Gas Development in Deepwater

It is well known that methane hydrate has been identified as an alternative resource due to its massive reserves and clean property. However, hydrate dissociation during oil and gas development(OGD) process in deep water can affect the stability of subsea equipment and formation. Currently, there is a serious lack of studies over quantitative assessment on the effects of hydrate dissociation on wellhead stability. In order to solve this problem, ABAQUS finite element software was used to develop a model and to evaluate the behavior of wellhead caused by hydrate dissociation. The factors that affect the wellhead stability include dissociation range, depth of hydrate formation and mechanical properties of dissociated hydrate region. Based on these, series of simulations were carried out to determine the wellhead displacement. The results revealed that, continuous dissociation of hydrate in homogeneous and isotropic formations can causes the non-linear increment in vertical displacement of wellhead. The displacement of wellhead showed good agreement with the settlement of overlying formations under the same conditions. In addition, the shallower and thicker hydrate formation can aggravate the influence of hydrate dissociation on the wellhead stability. Further, it was observed that with the declining elastic modulus and Poisson's ratio, the wellhead displacement increases. Hence, these findings not only confirm the effect of hydrate dissociation on the wellhead stability, but also lend support to the actions, such as cooling the drilling fluid, which can reduce the hydrate dissociation range and further make deepwater operations safer and more efficient.

Global oil and gas development in 2022:Situation,trends and enlightenment

Through analysis of four aspects,including the distribution and production of global oil and gas fields,the distribution and changes of remaining recoverable reserves,the differences in oil and gas production between regions/countries,and the development potential of oil and gas fields with production capacity not built and to be built,this paper presents the situation and trends of global oil and gas development in 2022.It is found that,in 2022,oil and gas fields are widely distributed worldwide,and upstream production activities continue to recover;the oil and gas reserves decrease slightly year on year,and the oil and gas reserves in sea areas increase significantly;the oil and gas production increases continuously,and the key resource countries make a significant contribution in oil and gas production growth;the oil and gas fields with production capacity not built and to be built hold abundant reserves,and their development potential will be gradually released with the economic benefits increase.Further analysis is conducted from the perspectives of global oil and gas resources continuity,geopolitical risks,potential of international cooperation,and upgrade of unconventional oil and gas technology.Finally,in view of core business domains and strategies under the new situation,the Chinese oil companies are recommended to:(1)keep a foothold in onshore conventional oil and gas development by virtue of their comparative advantages and learning from other’s experience in cooperation;(2)carry out pilot tests on development adjustment,and deepen the international cooperation in enhanced oil/gas recovery;(3)improve the oil and gas operation capabilities in sea areas to transform from follower as minority shareholder to joint venture and then to independent operations;and(4)seek appropriate ways for shale oil/gas development to reduce the dependence on foreign oil and gas.

Bargaining strategy of oil companies in international oil and gas development Projects-Based on a bilateral bargaining model

Bargaining between the host country and oil companies is very common to international oil and gas development projects.The existence of information asymmetry gives the host country an endogenous bargaining advantage.Foreign oil companies might change their unfavorable negotiating position by changing the order of bidding and adjusting bidding strategies.This paper introduces both factors into a bilateral bargaining model to study the impact of information asymmetry and bidding order on the strategy and equilibrium returns of oil companies.According to the ownership of the right to bid first,two scenarios are designed for the model to compare the equilibrium returns of the host country and oil companies.The results show that:1)There is a first-mover advantage in the process of bilateral bidding,so oil companies better bid first;2)The information asymmetry will lead to a higher nominal income ratio of oil companies and a lower nominal income ratio of the host country,but it doesn’t affect the total income ratio at all.

Oil and Gas Supply and Demand in China and Its Development Strategy

The paper makes a comprehensive prediction of China＇s future demand for oil and gas with two methods, i.e. the prediction method based on the demand for individual oil and gas products and the method for predicting the total demand. According to the demand prediction of, and the historical data on, the oil and gas consumption, we conduct an analysis of the oil and gas consumption trends, which can be described as six different development periods. On the other hand, the paper makes a comprehensive analysis of the domestic oil and gas resources and, on this basis, makes a basic prediction of the domestic output of oil and gas. The supply and demand situation is also analyzed. By using the SWOT analysis method, the paper puts forward the development strategies for China＇s oil and gas industry and gives some related strategic measures.

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

On December 2,2017,the 2^(nd) Seminaron 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",the

Development characteristics, models and strategies for overseas oil and gas fields

Based on about 20 years of accumulated experience and knowledge of oil and gas field development in overseas countries and regions for China's oil companies, the development features, ideas, models and plan designing strategies of overseas oil and gas fields were comprehensively summarized. Overseas oil and gas field development has ten major features, such as non-identity project resource, diversity of contract type, complexity of cooperation model, and so on. The overseas oil and gas field development aims at the maximization of production and benefit during the limited contract period, so the overseas oil and gas field development models are established as giving priority to production by natural energy, building large-scale production capacity, putting into production as soon as possible, realizing high oil production recovery rate, and achieving rapid payback period of investment. According to the overseas contract mode, a set of strategies for overseas oil and gas field development plans were made. For tax systems contracts, the strategy is to adopt the mode of "first fat and then thinner, easier in the first and then harder", that is, early investment pace, production increase rate, development workload and production were decided by the change of tax stipulated in the contract. For production share contracts, the strategy is to give priority to high production with a few wells at a high production recovery rate to increase the cost-oil and shorten the period of payback. For technical service contracts, the strategy is that the optimal production target and workload of the project were determined by the return on investment, so as to ensure that the peak production and stable production periods meet the contract requirements.

Research progress and challenges of natural gas hydrate resource evaluation in the South China Sea

As an efficient clean energy,natural gas hydrate(NGH)has become a hot topic in recent researches.Since1990 s,China has made great achievements and progress in NGH exploration in the South China Sea(SCS),including determination of the favorable distribution areas and favorable strata thickness,identification of the dual source for accumulation,evaluation of the prospective gas contents,verification of the widespread existence,and confirmation of the technical recoverability of NGH resources.However,there are three major challenges in the NGH studies.First,all the 24 national key and major projects in the SCS focused on trial production engineering and geological engineering in the past 20 years,while 8 of the 10 international NGH research projects focused on resource potential.Second,resource evaluation methods are outdated and some parameter selection are subjective.Third,the existing resource evaluation results are low-level with a great uncertainty,and cannot be used to guide NGH exploration and production or strategic research.To improve the evaluation of NGH resources in the SCS,future researches should focus on four aspects:(1)improve the research on the criterion of the objective existence of NGH and the method of prediction and evaluation;(2)apply new theories and methods from the global NGH research;(3)boost the research on the difference and correlation of the conditions of hydrocarbon migration and accumulation in different basins;(4)innovate the theory and method of NGH resource potential evaluation.

渤海不同类型稠油油藏开发策略研究

为提高渤海稠油油藏开发效益,根据油藏特征和海上生产条件,在开展冷采人工注水、热采转驱或蒸汽辅助重力驱(Steam Assisted Gravity Drainage,SAGD)的水体倍数界限、常规水驱与注蒸汽开发的流体性质界限和布井区油层厚度或油柱高度界限研究的基础上,结合先导试验认识与行业分类标准,提出了渤海稠油油藏分类标准并确定了不同的开发策略。普Ⅰ-1类稠油(50*~150*mPa·s),采用常规水驱、化学驱开发。普Ⅰ-2a类稠油(150*~350*mPa·s),采用常规水驱、热水驱开发。普Ⅰ-2b类稠油(350*~10000 mPa·s),弱水体油藏采用蒸汽吞吐、蒸汽驱开发;中、强水体油藏利用天然能量或人工注水开发;低油柱油藏采用火驱开发。特稠油块状底水稠油(10000~50000 mPa·s),采用蒸汽吞吐、SAGD开发的渤海不同类型稠油油藏开发策略与技术路线。研究结果为渤海稠油油田开发部署与技术攻关提供了依据。

国外深水钢悬链线立管研究发展现状

介绍国外在新型深水立管系统——钢悬链线立管关键技术方面的研究发展现状,论述浮体一、二阶运动对钢悬链线立管疲劳寿命的影响、浮体升沉运动对钢悬链线立管触地点疲劳寿命的影响;钢悬链线立管与海底相互作用机制的实验研究及结果;钢悬链线立管涡致振动与疲劳的研究现状。并简要论述钢悬链线立管触地点问题的研究结论。

国外深水油田开发模式

深水油气田与浅海及陆上油气田勘探开发相比,具有诸多难题和挑战:技术要求高,作业难度高,投资风险大。深水油田的开发目前已经成为世界投资的热点,但对于深水油田开发模式方面的研究报道还比较少。通过研究国外典型深水油田的勘探开发过程,从油藏特征、开发策略和动态开发规律等方面分析深水油田的开发模式,为深水油田高速开发模式的建立奠定基础,同时为中国南海海域深水油田的开发提供参考。

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。

从“剑桥能源周”看未来能源战略走势

第 37届剑桥能源周的基本共识:今后一个时期石油需求增长强劲,油气仍是未来能源主角,但能源转型是大势所趋;天然气作为洁净能源将继续引领化石能源发展,亚洲是需求增长主力;技术和管理创新对能源行业将产生巨大的颠覆性影响;石油公司将优化资产组合,加强战略合作;全球海上及深水油气业务将触底反弹;能源地缘政治态势恶化,对油气市场带来不确定因素;美国提出"能源新现实主义"命题与发展等。建议我国石油公司加强能源转型研究,制定切实可行的能源转型战略;加强传统领域技术创新与跨领域技术创新的融合;加强对美国"能源新现实主义"政策以及能源地缘政治的研究;抓住当前LNG买方市场机遇,择机签订LNG长贸合同。

中国石油海洋油气业务发展的机遇与挑战

海洋油气已成为全球油气资源的战略接替区,成为全球石油行业主要的投资领域之一。海洋油气勘探开发已进入深水油气开发阶段。中国石油的海洋油气业务经过十多年的发展,装备和技术水平不断进步,海洋油气勘探开发已从浅海走向深海、从国内走向国际,但实际工程技术能力与国家发展海洋、走向深海的要求相差甚远,深水工程技术能力不足的问题更加突显。国际原油价格跳崖式下跌以来,海洋石油工程技术服务、海洋工程装备建造市场量价齐跌,给公司的海洋油气业务发展造成了很大的挑战。但是,国家正在重点实施的"一带一路"和"中国制造2025"发展战略部署,又给海洋油气业务带来了机遇。建议中国石油利用此次海洋装备制造相对低价的机遇期,稳步发展海洋业务工程技术服务能力,加快深水能力建设进程。

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。

坐落管柱控制系统发展现状及国产化研究难点

坐落管柱是深水油气测试关键装备,遭遇特殊海况和紧急工况时可通过控制坐落管柱来实现油气封堵和测试管柱解脱,保障浮动平台安全撤离。随着海洋油气开发逐渐转向深水、超深水,坐落管柱控制系统已经历了直接液压控制、先导液压控制和电液控制等3个发展阶段,然而中国对坐落管柱控制系统的研究还处于起步阶段。详细介绍了坐落管柱控制系统组成、发展历程以及国内外研究现状,总结了坐落管柱3种控制系统的技术特征,包括响应时间、成本等;进一步通过对比现有国外产品,分析了坐落管柱控制系统整体发展趋势;最后结合中国实际情况,指出了坐落管柱控制系统国产化研究重点、难点。本文研究成果可为坐落管柱控制系统国产化提供参考。

进军深水——中国石油可持续发展的战略思考

当前中国石油勘探开发重点正逐步由常规向非常规、由陆上向海上、由滩浅海向深水海域转移。目前中国石油在资源、服务能力、技术能力等方面具备了走向深水的现实基础,但因自身深水工程技术能力不足,与国际先进水平比差距大,需要走有别于传统陆上的发展之路。围绕中国石油天然气集团公司深水探区勘探开发的迫切需求,提出了中国石油走向深水的目标,并绘制了发展路线图,对经营方式、装置配备、关键技术、人才培养和HSE管理等重点工作进行了论证。在此基础上,提出了制定深水工程技术能力发展规划及实施方案并推进实施、尽快开展推进核心装备与设施项目前期工作、积极争取政策支持等建议。

海上带凝析气顶的边底水油藏开发策略——以我国海上X油田H油藏开发为例

带凝析气顶的边底水油藏由于油气水关系复杂，开采难度大，容易出现油、气、水互窜，导致凝析油和原油的损失。对于这种复杂的油藏，不同的开采技术政策对油气采收率影响较大。以我国东部海域X油田 H油藏开发为例，在对气顶底水油藏的开发机理研究的基础上，结合海上油气田开发特点，提出带凝析气顶的边底水油藏开发策略：利用天然能量，先期以采油为主，后期兼顾采气；采用水平井开发，生产压差控制在1～1.5M Pa ，纯油区开采4～5a后封水平段油层，开采上部顶气。

深水油气勘探开发锚泊事故研究及对策分析

深水油气勘探开发锚泊事故主要包括锚索断开、走锚和制动系统失效等类型,如果控制不当可能造成人员伤亡、生产停产、平台碰撞倾覆和井喷等严重后果。鉴于此,通过调研国内外锚泊事故案例,总结事故失效类型以及各类事故的形成原因、影响因素和失效模式,提出了不同失效类型事故的预防措施和应对策略。分析了典型的外部影响因素对锚泊事故的影响,并提出台风和内波等外因影响下的锚泊事故风险应对策略。研究内容可为我国深水锚泊系统优化设计、制造加工工艺的改进以及风险分析提供参考,从而提高我国深水油气勘探开发过程中锚泊作业安全管理能力和事故应急能力。

中国海洋石油工业的发展战略

中国海洋石油工业2010年目标是生产5000万～6000万t油当量 发展战略是:坚持合作,加强自营,油气并举,向气倾斜,搁置争议,共同开发,增加储量,提高产量;海外合作,利用两种资源;开拓下游,建立上下游一体化的产业结构;进行股份制改造,建立完全的现代企业制度。

中国海洋石油报办报理念及其启示

作为企业报,面对时代发展提出的新要求和新挑战,中国海洋石油报不断探索新的发展思路。在定位上,准确把握国家战略、宏观经济和行业发展规律,科学确定发展方向;在视野上,坚持开门办报,不断拓宽国际视野;在组织上,充分借鉴企业的先进管理经验,确保高效运作;在人才上,打造复合型编辑记者团队,夯实发展根基。可以说,中国海洋石油报在中国海洋石油总公司的企业发展中发挥着重要作用。