涪陵地区页岩气井造斜井段提速研究

发布时间：2018-09-04 08:05

【摘要】：页岩气作为新兴的油气资源,很大程度上改变了现有的能源结构布局,拓展了油气能源开发的领域。页岩气并非是最近几年才发现的油气资源,在以往的钻井勘探开发中,钻遇泥页岩地层时就常有少量气体溢出,但并未作为有价值气源投入商业开发。大部分产气页岩分布范围广、厚度大,且普遍含气,使得页岩气井能够长期地稳定产气。但页岩气储集层渗透率低,开采难度较大。随着钻井技术的发展,水平井技术和水力压裂技术作为页岩气开发关键技术加快了页岩气发展的步伐。我国为加快页岩气勘探开发技术的发展,已将重庆涪陵页岩气项目作为国家级示范区,以形成页岩气高效开发配套技术措施。据现已钻井资料,涪陵地质条件复杂,浅层有溶洞和硫化氢气体、地层可钻性差、井壁亦不稳定、韩家店组井漏严重,这些都大大增加了钻井施工难度。为保证钻井开发安全高效进行,涪陵区块实施了多种钻井措施,本文主要研究涪陵造斜井段提速问题。造斜段所使用的提速钻井工艺主要为复合钻井技术以及针对井漏问题而实施的空气泡沫定向钻井技术,另外通过引入提速工具以提高造斜段钻井效率。复合钻井技术通过增加转速强化钻井参数以增强破岩能量,在涪陵地区已作为主要的提速措施进行应用,提速效果显著。为了配合复合钻井技术在造斜段的使用,合理的选择造斜率进行轨迹优化设计,增加复合钻井时效,降低滑动钻井时效,从而达到提高造斜段钻井速度的效果,轨迹控制能力满足要求。由于在造斜井段,螺杆不仅仅提供定向造斜的作用,而且复合钻进螺杆也持续保持着高速旋转,这些都很大程度上增加了螺杆的工作强度,导致螺杆寿命较短,一旦螺杆出现故障,就需要起下钻更换,大大增加了钻井间断时间,因而螺杆成为造斜段钻进中较为脆弱的环节。基于复合钻井表现出来的螺杆寿命短问题,本文通过对比已钻井资料,优选了立林厂家螺杆,其寿命长,满足施工要求。通过对比分析,等壁厚螺杆较常规螺杆使用效果稳定,寿命更长。另外,合理的施工规程和措施是提高螺杆寿命的重要手段。为改善造斜段托压问题,在造斜段施工中引入了辅助提速工具水力振荡器和液力推进器,根据钻井效果分析,水力振荡器使用效果较好,在使用井段钻时降低明显。造斜段地质复杂,海相地层分布,韩家店组、小河坝组井漏问题大大增加了钻井间断时间。为解决这一问题,涪陵区块引入泡沫定向钻井技术,定向造斜率0.15-0.220/m,满足定向施工要求。依据涪陵地质情况,对涪陵区块空气泡沫钻井技术可行性进行了分析,掌握涪陵区块出水出气情况是实施空气钻井技术的先决条件。同时,井壁稳定也是空气泡沫钻井主要问题,据焦页1HF井取岩心分析,岩石表现为水平裂缝发育,垂向无裂缝,嘉陵江组—小河坝组地层岩石抗压强度曲线显著高于地层坍塌曲线,空气泡沫钻井井壁较为稳定。焦页13-1HF井使用泡沫定向钻井,进尺524.140m,相比邻井对应井段提速效果显著。在钻井过程中,钻杆磨损严重、携岩能力不足是空气泡沫钻井主要问题。针对携岩问题,本文通过修正的Angel模型对空气泡沫钻井最小注气量进行了计算,为钻井施工提供有效的参考。
[Abstract]:Shale gas, as a new oil and gas resource, has greatly changed the existing energy structure and expanded the field of oil and gas energy development. Shale gas is not a newly discovered oil and gas resource in recent years. In the past drilling exploration and development, a small amount of gas spills out when drilling shale formation, but it is not a valuable gas source. Most of the gas-producing shale rocks are widely distributed, thick and generally gas-bearing, which enable shale gas wells to produce gas steadily for a long time. However, the permeability of shale gas reservoirs is low and it is difficult to exploit. With the development of drilling technology, horizontal well technology and hydraulic fracturing technology, as key technologies of shale gas development, accelerate shale gas generation. In order to speed up the development of shale gas exploration and development technology, Chongqing Fuling shale gas project has been taken as a national demonstration area to form a complete set of technical measures for efficient shale gas development. In order to ensure the safe and efficient drilling, Fuling block has implemented a variety of drilling measures. This paper mainly studies the problem of increasing the speed of Fuling inclined section. The speed-increasing drilling technology used in the inclined section is mainly composite drilling technology and the air for the leakage problem. Foam directional drilling technology, in addition to the introduction of speed-increasing tools to improve drilling efficiency in the deviated section. Composite drilling technology through increasing drilling speed to enhance drilling parameters to enhance rock breaking energy, Fuling area has been used as the main speed-increasing measures, speed-increasing effect is significant. In order to coordinate with the use of composite drilling technology in the deviated section, reasonable. The trajectory control ability meets the requirements by optimizing the trajectory design by choosing the build-up rate, increasing the composite drilling efficiency and reducing the sliding drilling efficiency, thus increasing the drilling speed in the build-up section. The working strength of the screw is increased to a great extent, and the life of the screw is shorter. Once the screw fails, it needs to be replaced by taking-off drilling, which greatly increases the drilling interruption time. Therefore, the screw becomes a vulnerable part in the drilling of the deviating section. By comparison and analysis, the screw with equal wall thickness is more stable than the conventional one, and the life of the screw is longer. In addition, reasonable construction rules and measures are important means to improve the life of the screw. Hydraulic oscillator and hydraulic propeller have been used in this area. According to the analysis of drilling effect, the use of hydraulic oscillator is better, and the decrease is obvious when drilling in wellbore section. According to Fuling geological conditions, the feasibility of air foam drilling technology in Fuling Block is analyzed. It is a precondition to implement air drilling technology to master water and gas production in Fuling Block. Core analysis shows that the rock has developed horizontal fractures and no vertical fractures. The compressive strength curve of Jialingjiang-Xiaoheba formation is significantly higher than the collapse curve, and the borehole wall of air foam drilling is more stable. During the drilling process, the main problems of air foam drilling are serious wear of drill pipe and insufficient rock-carrying capacity. Aiming at the problem of rock-carrying, this paper calculates the minimum gas injection rate of air foam drilling by using the modified Angel model, which provides an effective reference for drilling operation.
【学位授予单位】：长江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE24

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