Dynamic Analysis Method of Offshore Jack-up Platforms in Regular and Random Waves

A jack-up platform, with its particular structure, showed obvious dynamic characteristics under complex environmental loads in extreme conditions. In this paper, taking a simplified 3-D finite element dynamic model in extreme storm conditions as research object, a transient dynamic analysis method was proposed, which was under both regular and irregular wave loads. The steps of dynamic analysis under extreme conditions were illustrated with an applied case, and the dynamic amplification factor （DAF） was calculated for each response parameter of base shear, overturning moment and hull sway. Finally, the structural response results of dynamic and static were compared and analyzed. The results indicated that the static strength analysis of the Jack-up Platforms was not enough under the dynamic loads including wave and current, further dynamic response analysis considering both computational efficiency and accuracy was necessary.

Design of A Bionic Spudcan and Analysis of Penetration and Extraction Performances for Jack-up Platform

The mechanisms of soil structure interaction have drawn much attention in the past years in the installation and operation of jack-up platform. A bionic spudcan produced by biomimetic of egg and snail shell is proposed, and the performance of the penetration and extraction are analyzed by numerical method. The geometric contour of egg and snail shell is measured, and its mathematical model is established respectively. According to the structure of existing spudcan of jack-up platform, three kinds of typical biomimetic spudcan are designed. Furthermore, numerical analysis models of biomimetic spudcan are established respectively to study the soil structure interaction mechanism in the process of penetration and extraction, and contrastive analysis of resistance characteristics are carried out. To conclude, the results show that the biomimetic spudcan facilitates the platform installation, and it is also beneficial to the improvement of the bearing capacity of spudcan.

Soil-Structure Interaction Analysis of Jack-up Platforms Subjected to Monochrome and Irregular Waves

As jack-up platforms have recently been used in deeper and harsher waters, there has been an increasing demand to understand their behaviour more accurately to develop more sophisticated analysis techniques. One of the areas of significant development has been the modelling of spudean performance, where the load-displacement behaviour of the foundation is required to be included in any numerical model of the structure. In this study, beam on nonlinear winkler foundation （BNWF） modeling--which is based on using nonlinear springs and dampers instead of a continuum soil media--is employed for this purpose. A regular monochrome design wave and an irregular wave representing a design sea state are applied to the platform as lateral loading. By using the BNWF model and assuming a granular soil under spudcans, properties such as soil nonlinear behaviour near the structure, contact phenomena at the interface of soil and spudcan （such as uplifting and rocking）, and geometrical nonlinear behaviour of the structure are studied. Results of this study show that inelastic behaviour of the soil causes an increase in the lateral displacement at the hull elevation and permanent unequal settlement in soil below the spudcans, which are increased by decreasing the friction angle of the sandy soil. In fact, spudeans and the underlying soil cause a relative fixity at the platform support, which changes the dynamic response of the structure compared with the case where the structure is assumed to have a fixed support or pinned support. For simulating this behaviour without explicit modelling of soil-structure interaction （SSI）, moment- rotation curves at the end of platform legs, which are dependent on foundation dimensions and soil characteristics, are obtained. These curves can be used in a simplified model of the platform for considering the relative fixity at the soil- foundation interface.

The Calculating Model of Structural Analysis for Jack-Up Rig Legs

The selection or establishment of structural calculating model is a matter of primary importance in structural analysis. By analysing the irrationality of the calculating models used by some research organizations at home and abroad in structural analyses for truss jack-up rig legs, this paper introduces a new calculation model which is more reasonable. This model can simulate better the load situation of a rig reflecting more precisely the effects of the leg loads caused by the spring support of gearboxes of the jacking system and the secondary bending moment raised by hull displacement under extreme conditions. The rig conversion was completed in 1989. In July 1991 the rig safely stood the frontal hitting of Typhoon with the wind speed of 52 m / s, which shows that the checking on the structure is correct.

Collision Analysis Between Spudcan and Seabed During the Process of Jack-up Platform Lowering Jack-up Legs

In the leg-lowering process,the offshore jack-up platform is in a floating state,and the spudcan may collide with the seabed due to the platform motion in waves,thereby threatening the safety and stability of the platform.This paper first analyzed the hydrodynamic response of a jack-up platform under different sea states.Then a finite-element model was established which considered the material and geometrical nonlinearity in the structure and the nonlinear interaction between soil and structure to investigate the collision response between the spudcan and seabed during lowering jack-up legs.The results show that the dynamic response of the platform decreases and gradually tends to be stable as the wave period increases.The motion response of the platform reach the largest value when the wave period is 8 s and the wave direction is 0°.The collision angle between the spudcan and seabed has a large influence on the collision response,while the velocity of leg-lowering has little influence on the collision response.The collision response is also significantly affected by soil conditions.For clay,the increase in undrained shear strength and Young’s modulus will increase the impact force.

中国石油井下作业数字化监督发展问题与对策

阐述了中国石油井下作业数字化监督在监督人员数字化管理、施工队伍数字化监督、施工作业数字化监督、井场环境数字化监督4个方面的发展现状。分析了井下作业数字化监督发展面临数字化监督管理制度不健全、监督数据标准不统一、数字化智能监督技术不完善、缺少统一的数字化智能监督平台、监督数据价值挖掘不深入5个方面的主要问题。提出了制定井下作业数字化监督管理制度、建立井下作业监督数据标准、攻关数字化智能监督关键技术、研发井下作业数字化智能监督平台、提升监督大数据分析应用水平5项数字化监督发展对策。展望了井下作业数字化监督建设发展后在提升监督人员履职效率、降低监督人力资源成本、提升工程质量、保障施工安全与环保4个方面的预期成效。

石油钻井平台装备电动化进程及趋势

针对国内外电驱动管柱自动化作业装备开展技术研究,分析了美国Canrig公司钻台机器人、排管机器人、电动铁钻工、输管机器人,美国NOV公司钻台机器人及其相关自动化作业系统,法国道达尔公司巡检机器人7类产品的功能、特性等;论述了国内电动扶管手、二层台机械手、指梁、巡检机器人等技术和应用现状。通过技术对标分析得出:国内外石油钻机装备均向智能、高效、绿色化发展,钻井作业由传统人力操作逐步向自动化、智能化转变;国外装备在小体积大功率驱动、防尘防水、防爆防盐雾、多轴协同等关键技术突破方面优于国内,而其在产品多样性以及应用推广方面与国内差距明显。建议国内基于电传动系统的特点,突破传统理念,研发新型高效装备;以及在装备自主决策、故障诊断等方面加大技术攻关力度。研究结果可为我国石油钻井装备技术发展提供参考。

连续复合管缆投捞式人工举升技术研究

海上无修井机平台依赖钻井船修井,费用高、时效慢,现有非常规作业技术对平台条件要求高,难以推广。为此,开展了连续复合管缆投捞式人工举升技术研究和应用。针对复杂井况和无修井机平台特点,对管柱和井下工具结构进行了优化设计,通过管缆选型计算和电泵扬程拟合,在南海西部涠洲11-1A平台A21H1井进行了先导性应用。研究结果表明:连续复合管缆投捞式人工举升工艺优化了管柱结构,取消湿接头设计,增设液控滑套,生产期间可实现换层;采用特质动力电缆集成的连续复合管缆强度大,防腐能力增强,大大降低了作业风险;完成了在A21H1井的不压井作业,目前该井投产后日增油60 m^(3)。研究结果可为海上油田无修井机平台的修井作业提供技术支撑。

连续管缆投捞电泵技术在南海西部油田的应用

为了解决海上无修井生产平台,电泵采油井进行检泵或换泵作业时动用钻井船,导致修井费用高。通常钻井船作业资源协调困难,鉴于此种情况研发了一种连续管缆投捞电泵技术。该技术将电泵采油技术与连续油管技术相结合,将动力电缆和液控管线集成在连续油管里组成连续管缆,利用连续油管设备操作连续管缆进行电泵机组的起下作业,井下电泵机组与动力电缆直接连接供电,实现对井筒流体的举升。在南海西部油田的应用案例表明,该配套技术成熟,具有检泵作业工期短、产量恢复快、修井综合成本低的特点,为无修井机生产平台检泵或换泵作业提供了新选择。

海洋模块钻机钻井仪表和电控系统集成优化技术研究

随着海上油气开采的不断深入,模块钻机自动化程度越来越高,开展钻井仪表和电控系统集成优化研究具有重要意义。介绍了海洋模块钻机控制技术现状,并在此基础上进行深入研究,提出了一套以PLC控制技术为基础,将钻井仪表系统、泥浆泵控制系统、绞车电控系统及顶驱电控系统集成为一体化电控系统的优化方案,可为同类海洋模块钻机的设计提供借鉴。

Prediction Methods of Spudcan Penetration for Jack-up Units

Jack-up units are extensively playing a successful role in drilling engineering around the world, and their safety and efficiency take more and more attraction in both research and engineering practice. An accurate prediction of the spudcan penetration depth is quite instrumental in deciding on whether a jack-up unit is feasible to operate at the site. The prediction of a too large penetration depth may lead to the hesitation or even rejection of a site due to potential difficulties in the subsequent extraction process; the same is true of a too small depth prediction due to the problem of possible instability during operation. However, a deviation between predictive results and final field data usually exists, especially when a strong-over-soft soil is included in the strata. The ultimate decision sometimes to a great extent depends on the practical experience, not the predictive results given by the guideline. It is somewhat risky, but no choice. Therefore, a feasible predictive method for the spudcan penetration depth, especially in strata with strong-over-soft soil profile, is urgently needed by the jack-up industry. In view of this, a comprehensive investigation on methods of predicting spudcan penetration is executed. For types of different soil profiles, predictive methods for spudcan penetration depth are proposed, and the corresponding experiment is also conducted to validate these methods. In addition, to further verify the feasibility of the proposed methods, a practical engineering case encountered in the South China Sea is also presented, and the corresponding numerical and experimental results are also presented and discussed.

履带式全空间液压钻机的研制及应用

针对现有公路隧道注浆钻机存在施工高度有限、灵活性差、钻孔施工效率低的问题,研制了一种履带式全空间液压钻机,采用有限元方法对钻杆和钻头进行了强度分析,建立数学模型对冲击作用下的钻机进行了稳定性分析,并应用于江西南石壁隧道注浆治理中。研究结果表明:该钻机可在3~9 m内实现隧道内全方位钻孔,主要受力构件满足强度、刚度的使用需求,最大动态稳钻压力作用下,该钻机能保持自身稳定。履带式全空间液压钻机解决了现有隧道注浆钻机施工高度不足、靠孔姿态调整范围小的问题,有效提高了隧道注浆钻孔效率。

深水平台控压钻井技术浅析

窄密度窗口、漏溢同存、高温高压已成为深水钻井实现安全高效钻探所面临和亟待解决的难题。控压钻井技术已在我国陆地和浅海取得良好应用效果,国内深水领域还未系统开展控压钻井工艺和装备的攻关研究。调研分析我国南海某工区钻井工程需求,文章在此提出将旋转控制头安装在张力环下方的深水控压钻井技术,从系统的组成和功能方面阐述控压钻井隔水管水下子系统和控压钻井平台管汇系统;从平台工作状态、控压钻井隔水管水下子系统部署时序、钻井液循环特点等方面与自升式平台控压钻井进行对比分析;以井底压力为研究目标开展平台升沉、大排量钻井、增注/节流参数等因素对其影响的模拟计算。在此基础上指出我国深水控压钻井应从工艺、井底压力波动机理及控制方法、实时水力计算软件研发等方面开展攻关研究,满足深水钻井工程需求,助力深水油气资源高效勘探开发。

跨海大桥超低净空嵌锚式支座快速更换技术研究

某大桥为等截面预应力混凝土刚构-连续体系,标准跨径为70m。全桥支座为球形钢支座,最小支座高度仅为8.9cm,支座锚栓均采用永久性地脚锚栓锚固方式(嵌锚式支座)。2016年经过检测,该桥梁支座均出现不同程度滑板磨损开裂、锚固螺栓干涉、位移超限等病害,需全部更换。但受限于旧支座锚栓为地脚螺栓锚固方式,新支座安装存在旧支座螺栓无法重新使用、超低净空下需异位重新钻孔及低净空长锚栓植入等技术难题,国内尚属首次。以该桥支座更换难点为背景,提出针对性解决技术并得到成功应用。结果表明,该系统化技术可大幅缩短工期和降低成本。

基于云平台的石油钻机智能管理维护系统研究

针对石油钻机设备远程管理、平台监测、智能维护等的需求,设计了基于云平台的石油钻机智能管理维护平台,文章从平台的应用需求、方案设计、系统架构、功能应用等方面进行了详细阐述。并针对管理维护平台的网络拓扑、总体业务规划、信息采集传输、数据存储分析等关键技术进行了研究。平台可实现对不同种类、型号的石油钻机设备进行统一管理、实时监测、故障分析、智能运维等功能。为实现钻机关键设备全生命周期管理、预测性维护及降低钻机设备非计划停机率、故障率奠定了基础。

渤海某油田模块钻机设备升级改造

渤海某油田钻机设备服役年限均超过12年,在过去十几年里为祖国能源事业做出巨大贡献。随着平台服役年限的增加平台生产面临诸多问题,包括设备能力不足、分流器常规安装受限、防砂设备无法上平台等问题。为了解决这些问题并降低工作成本,形成一套适用于该油田的模块钻机设备升级改造技术。该技术推动了该油田设备设施升级,提高了油田深度挖潜的能力,并已取得良好的应用效果和经济效益。该技术方案可用于其它类似生产平台模块,具有良好的推广价值。

逆作桩柱一体安装加设回转钻机平台混凝土底座施工技术研究

逆作桩柱一体安装施工技术在不同结构工程中应用广泛,为控制好钢管柱垂直度,解决逆作桩柱一体安装施工过程中钢管柱环板与回转钻机平台夹持作用位置点冲突问题,以克服钢管柱插入桩内混凝土时产生的浮力阻碍。该文结合北京城市副中心站综合交通枢纽工程,重点介绍桩柱一体安装施工工艺、回转钻机平台混凝土底座的原理及作用。应用该技术解决桩柱一体安装施工的难题,为同类工程施工提供参考。

煤矿救援钻机井口平台的结构设计与优化研究

救援钻机是煤矿应急处置的关键设备,是事故发生后的紧急救援工具。现有地面应急救援车载钻机整体井口平台结构形式不灵活,存在开口孔径小、拆装困难、不能满足大直径钻头和套管下放的问题。基于此,结合救援施工要求,提出了一种模块化且大开口车载钻机智能井口平台总体方案。模块化井口平台具有快速对中、夹紧、自动调平、满足多系列大直径钻具要求的特点。采用数值模拟方法对U型井口平台进行分析,并根据原结构的分析结果提出优化结构。结果表明,优化后的结构应力优于原始结构,为救援钻机结构设计与优化提供了重要支持。

便携式钻机在海上平台进行勘察的应用实践

为提高海上钻探施工效率、避免传统立轴式钻机在海上施工时易受到波浪和潮汐影响、钻进取心效率低、存在安全风险且易发孔内事故的难题,依托青岛胶州湾第二海底隧道勘察项目,在近海海上平台尝试使用了便携式钻机。介绍了近海海上常用的不同类型平台,提出便携式钻机在海上固定式平台和浮动平台上的钻进取心实施方案。探索研究出一种便携式钻机在浮动平台上的波浪补偿绳索取心钻进方法。高效、安全地完成了钻探任务。所提出的方案对同行有参考借鉴作用,有利于海洋工程的勘察。

地质岩心钻探标准化机台建设探索与实践

地质岩心钻探工程是一个复杂、综合的施工体系,其作业所用的钻机、钻塔、附属设备及工器具等金属器件繁多,作业环境复杂,影响安全施工的不确定性因素众多。从规范机台施工秩序、提高机台管理水平、减少生产安全事故、改善施工作业环境等方面考虑,推行机台标准化建设具有重要的意义。文章重点介绍了我单位在机台标准化建设方面取得的一些经验做法,重点论述了施工现场标准化、装备管理标准化、施工管理标准化3个方面的做法,分析了标准化机台建设具有安全性高、规范化好、易于管理等优势,在甘肃寨上、陕南及北山等勘查区的推广实施,取得了良好效果,并为钻探行业施工更加规范化、制度化提供了参考。