鄂尔多斯盆地布署的天然气风险探井完钻层位已进入年代古老的元古界、太古界地层,元古界长城系地层沉积年代远、地层埋藏深(4000～6000 m),岩性致密、研磨性强、可钻性差,常规钻井机械钻速低(0.3～0.5 m/h)、钻头易磨损.文章针对长城系地层常规钻井存在的技术难题,开展了氮气钻井适应性分析、提速可行性分析、钻头优选等氮气钻井提速关键技术研究,并在鄂尔多斯盆地中西部天然气探井T105井、T91井长城系地层进行氮气钻井提速验证试验,实现了三开氮气钻井"一趟钻"作业,钻头寿命增加明显,提速效果显著,平均单只钻头进尺200 m,长城系地层平均机械钻速2.16 m/h,同比常规钻井提速4倍以上,为长城系地层钻井提速提效提供了新手段.

As a large-scale,standardized and flow-oriented high-level fracturing mode,the factory fracturing puts forward higher requirements for fracturing equipment and its matching facilities.Surface equipment,which are an important part of the factory fracturing technology,have a significant impact on the implementation of the factory fracturing.The equipment facilities status of foreign factory fracturing and the difficulties of equipment facility in China have been analyzed.The present situations of China's factory fracturing equipment have been systematically introduced,including continuous water supply,continuous mixing,continuous sand transport,continuous pumping and fracturing fluid recycling.In view of the actual applications and the encountered problems in domestic oilfield,advices on the future development of domestic surface equipment for factory fracturing have been proposed:improving the level of China's factory fracturing surface equipment should be speed up in the aspects of application improvement,matching facility optimization and technical specification establishment,so as to promote the application of factory fracturing technology in China.

水平井的钻井技术起源于上个世纪三十年代，发展是在八十年代，随着现代的对原油采油量采收率越来越重视，为了降低开发生成的成本，对水平井的钻井技术进行了研究和讨论，并对水平井的钻井技术的发展方向进行了探讨。我国水平井的钻井技术广泛应用在各种油气藏，并取得明显的经济效果，促进了水平井的钻井技术应用规模快速发展，在国内，以长庆油田、胜利油田为代表对一些油田实施水平井的钻井技术并开发了各种油气藏，并且收到了显著的效果，获得较好的经济效益。目前我国对水平井的钻井技术项目越来越重视它的先进性和适用性，并且对油藏地质和水平井的完钻技术以及采油作业技术有机的结合起来，使水平井的钻井技术能够迅速的发展，这也是国内水平井的钻井技术的未来发展方向。

Because of better developed corrosion holes and cracks in Ordovician Kelimoli group and Bench Mt group of the western Ordos Basin, Changqing Gas field, and lower formation pressure coefficient, lost circulation and reservoir damage problems have always constrained gas exploration and development in the region. In recent years, the aerated nitrogen drilling supporting technology was researched in Lower Paleozoic formation of the western Ordos Basin, including gas injection fluid parameter optimization, aerated nitrogen drilling equipment, well control safety, and etc. Field test has obtained success, solving the lost circulation problem in Lower Paleozoic formation, obtaining better effect in reservoir protection and speed raising, and providing new ways for exploration and development of the western Ordos Basin, and then it provided guidance for lost circulation treatment and aerated nitrogen drilling operation.

The application of nitrogen drilling at the highly abrasive gas-bearing Xujiahe Formation of the LG area is critical for the ROP improvement,reservoir protection,prevention of downhole explosion,and for further exploration and development in this area.Hereby,according to the practices and experiences from the nitrogen drilling in this formation on many wells,we summarized the equipments used,the technical challenges encountered,and the measures adopted as follows:1) the drilling rate should be controlled to be over 5 min/m in order to avoid sticking;2) if serious sticking occurs,work the drill string at a controlled pull force,and keep circulating continuously till no obstruction in the annulus,then readjust the work distance of the drill string in order to free it.The successful application of nitrogen drilling at the Xujiahe formation has proved that nitrogen drilling can not only improve the ROP effectively,but avoid downhole fires or explosions when drilling through gas zones with air.

Gas drilling has been widely used in northeast Sichuan area gradually.It not only can greatly increase the penetration rate,shorten the construction cycle,reduce drilling costs,but also can improve the rate of exploratory wells and enhance recovery ratio.Anticipating the complex characteristics of gas drilling in the course of drilling,using the immediate symptoms during before or during the accident occurred to forecast and treat down hole accidents timely is key of gas drilling.The paper summarized some symptoms of yielding water,borehole collapse and hole deviation in northeast Sichuan area by practice.Meanwhile,the method on how to diagnose complicated downhole problems according to these symptoms was described,and some processing methods on formation water output,hole sloughing,borehole inclination and so on were put forward.

Air drilling has two advantages of increasing ROP and formation protection, and the air drilling is developed rapidly in China. With the air drilling, a lot of new oil and gas resources have been discovered. Although the air drilling has its advantages, the limitations of the air drilling process must also be regarded. The technology of air drilling had improved rapidly with the air drilling was taken into account by the petroleum industry, but excessive formation water, wellbore stability, sulfide formation, downhole fire etc. issues have restricted the air drilling. Integrating the field trial in SuLiGe area of ChangQing, the paper analyses the complex condition accompanying air drilling and have formed a series methods dealing with the complicate problem in air drilling.