Abstract:The problem of hole-wall stability includes the well collapsing and the well fracture. The formation of ultra-deep scientific drilling (UDSD) is provided with high stress, high temperature and high formation pressure. The hole-wall stability of UDSD is one of the focuses. Take the example of 12000m UDSD, starting from the formation temperature, analysis was made on the changes of equivalent static density of drilling fluid and annular pressure equivalent density caused by drilling fluid circulating temperature, and on the influence to hole-wall stability by formation temperature-gradient stress and formation temperature-difference stress.

Abstract:Drilling is a direct and effective means for getting geological material. During the drilling period, the complex conditions are frequently encountered such as strata leakage, hole wall collapsing and diameter shrinking, etc. Due to the unstable borehole wall, drill sticking and burying often happen. If it is not timely and properly treated, borehole scrap would be inevitable. In order to get the core fast, safe and accurate, the rule “prevention first, prevention & treatment combination” should be obeyed from the initial design. With the case of Shanggong gold mine, the principle of one level diameter reserved before drilling and drilling with casing & drilling fluid plugging were summarized, which could be the technical reference for the subsequent drilling work.

Abstract:Continuous coring drilling for rock salt was succeeded with good effect by using water well rig, developing rock salt coring drilling; taking rational borehole structure and optimizing drilling assembly with proper saturated saltwater drilling fluid and coring drilling technology. According to the rock salt survey project of Puyang, the paper introduced coring drilling technology for deep rock salt.

Abstract:According to the collapsing and leakage in some individual borehole of Shengjingzi oil shale mining area in Jilin, taking PVA as main material, the flush fluid was prepared with better cementation and inhibition properties for collapsing prevention and wall protection. Economical and practical inert materials such as sawdust and peanut shell were used for leakage stoppage to lower the accident rate and drilling cost as well as improving the drilling efficiency.

Abstract:The medium exploration wells of Yaoyingtai, Qinjiatunbawu, Qinjiatunshiwu block and surrounding Lishu fault depression and Changling fault depression of Songliao area in Jilin are important in China Petroleum & Chemical Corporation of northeast area, as well as shallow gas well of Fulongquan. Different efficiency improvement measures were respectively made according to the characteristics of each well. Through constant bit optimization, enhancing drilling parameters, adopting high power and high temperature composite screw drilling technology, designing detailed single well drilling schemes and developing efficiency potential, the best drilling record was obtained. The paper introduced the optimized and fast drilling technical schemes and the specific measures in Songliao area.

Abstract:Nitrogion foam under-balanced drilling test was made to effectively release gas reservoir and evaluate the technical and economic feasibility of under-balanced horizontal well in developing He 1 gas reservoir of Daniude gas field, whole process under-balanced was realized to protect the gas reservoir with higher penetration rate than common horizontal well drilling. It provides the technical reserve for the development of Daniudi low permeability gas field.

Abstract:There is possibility of circulation loss and collapse in the upper stratum of Jiulongshan region, strong abrasivity and extremely poor drillability in the middle stratum, and multiple field and pressure system in the lower stratum. In order to cope with the abnormal situation, this well is designed to use gas drilling. The stratum is gassing when air drilling was dilled to 1170.28m. Then switch to nitrogen drilling, but when drilled to 1868m, it is wellface collapsed and drill stem blocked and sticking. At last it must finish the gas drilling. The paper records a main gas concentration changes and the handing measures of the abnormal condition during the drilling process, and provides some experiences to gas drilling crews dealing with abnormal condition. In conclusion, gas drilling have more advantage than conventional drilling in preventing circulation loss, stratum gassing without H2S, and abnormal pressure.

Abstract:Sidetracking in open hole is one of the most popular drilling technologies. Unknowing sidetracking or only with single sidetracking method, the construction time would be longer, more well sections would be lost with tools and instrument loss, even with failure. Some key problems of sidetracking are studied and discussed in this paper; principles of kick-off point are given and the evaluation of tools and control drilling by time or weight on bit are brought forward. In addition, sidetracking in a well is taken as an example to describe the technologies.

Abstract:Ｔｈｉｓ ａｒｔｉｃｌｅ ｅｌａｂｏｒａｔｅｄ ｔｈｅ ｖａｌｕａｂｌｅ ｅｘｐｅｒｉｅｎｃｅ ｗｉｔｈ ｔｗｏ ｅｘａｍｐｌｅｓ ｔｈａｔ ｔｈｅ ａｃｉｄｉｆｉｃａｔｉｏｎ ａｎｄ ｃｒｕｓｈｉｎｇ ｔｅｃｈｎｏｌｏｇｙ ｃａｎ ｂｅ ｕｓｅｄ ｔｏ ｉｎｃｒｅａｓｅ ｇｅｏｔｈｅｒｍａｌ ｅｘｐｌｏｉｔ ａｍｏｕｎｔ．Ａｃｉｄｉｆｉｃａｔｉｏｎ ａｎｄ ｃｒｕｓｈｉｎｇ ｔｅｃｈｎｏｌｏｇｙ ｉｓ ｗｏｒｔｈ ｔｏ ｓｐｒｅａｄ ｉｎ ｇｅｏｔｈｅｒｍａｌ ｅｘｐｌｏｒａｔｉｏｎ， ｗｈｉｃｈ ｃａｎ ｂｅ ｕｓｅｄ ａｃｃｏｒｄｉｎｇ ｔｏ ｇｅｏｌｏｇｉｃａｌ ｃｏｎｄｉｔｉｏｎｓ ｉｎ ｉｍｐｒｏｖｉｎｇ ｇｅｏｔｈｅｒｍａｌ ｙｉｅｌｄ ｃｏｎｓｔｒｕｃｔｉｏｎ ｉｎ ｔｈｅ ｃａｒｂｏｎ- ａｔｅ ｇｅｏｔｈｅｒｍａｌ ｒｅｓｅｒｖｏｉｒｓ ｗｈｉｌｅ ｔｈｅｙ ａｒｅ ａｓ ｔｈｅ ｔａｒｇｅｔ ｌａｙｅｒｓ．Ｂｅｆｏｒｅ ｔｈｅ ａｐｐｌｉｃａｔｉｏｎ， ａｔｔｅｎｔｉｏｎ ｓｈｏｕｌｄ ｂｅ ｐａｉｄ ｔｏ ｔｈｅ ａｎａｌｙｓｉｓ ａｎｄ ｓｔｕｄｙ ｏｎ ｔｈｅ ｂａｓｉｃ ｇｅｏｌｏｇｉｃａｌ ｄａｔａ， ｅｓｐｅｃｉａｌｌｙ ｏｎ ｔｈｅ ａｎａｌｙｓｉｓ ｏｎ ｐｕｍｐｉｎｇ ｔｅｓｔ ｄａｔａ ｂｅｆｏｒｅ ａｃｉｄｉｆｉｃａｔｉｏｎ； ａｐｐｌｉｃａｔｉｏｎ ｐｒｅ- ｒｅｑｕｉｓｉｔｅ ｏｆ ａｃｉｄｉｆｉｃａｔｉｏｎ ａｎｄ ｃｒｕｓｈｉｎｇ ｔｅｃｈｎｏｌｏｇｙ ａｌｓｏ ｓｈｏｕｌｄ ｂｅ ｍａｄｅ ｃｌｅａｒ ｉｎ ｏｒｄｅｒ ｔｏ ａｃｈｉｅｖｅ ｔｈｅ ｉｄｅａｌ ｅｆｆｅｃｔｓ．

Abstract:Based on the construction environment and the conditions, according to the characteristics of red layer of central Yunnan, different drilling equipments and well completion technologies were adopted in the southwest drought resistance at the beginning of 2010. Favorable technically economic effect and important social benefit were gained by fast and effective well completion, drinking water crisis was solved for local people and domestic animals. This article describes the technology methods and construction experience of improving well quality and drilling speed in the red layer of central Yunnan, such experience can be used as reference to the future drilling projects with the similar conditions.

Abstract:Air downhole hammer drilling has played important role in well construction for drought resistance in the mountain area of western Henan, where is a bed rock area seriously short of water. The paper introduced the practical application, the operation points and the advantages of the technology in well construction. Further discussion and summary were made on the application effects of air downhole hammer drilling technology in fault fracture zone and well developed formation.

Abstract:The current environmental issue is gained more and more attention by people; indispensable sampling project becomes a key of study on environmental science. To get a good environmental sampling result, the phenomenon of the core blocking, core lost, samples being washed, the hole wall collapsing, and so on must be overcome. Press-fitting sampling drilling tool of three layer pipes of water insulation style is mainly designed for loose and soft formation sampling. It has been proved by practice in Daihai Lake that press-fitting sampling drilling tool of three layer pipes has a very reliable performance and can meet the requirements of coring rate of 100% in environmental science core drilling.

Abstract:DTH drilling with casing is an effective means to deal with drilling in complex strata. However, the case is usually broken in practical application. Based on the finite element analysis, it is the relation between size and position of case tool escape that causes the case fatigue damage. To solve this problem, pipe shoe was lengthened in order to weaken the impact on case. Compared to the original design, stress and strain of the improved case were dramatically declined with force status greatly improved. The results of field test indicate that the improving scheme is practical and effective.

Abstract:It is the first time to use outrigger diaphragm wall in Hangzhou area. Based on the practice, this thesis presents main technical points of outrigger diaphragm wall. By the tracking analysis on the practical construction procedure, the whole technological process and technical measures for ensuring construction quality of outrigger diaphragm wall, the excavation depth of basement and the security and stability of foundation pit. The application prospects of outrigger diaphragm wall were presented.

Abstract:The composite soil-nailing has been wildly used in the soft soil zone, but its theory for design and calculation cannot satisfy the present project application. With the aid of the non-linear plane strain finite-element, the distortion performance of composite soil-nailing during the step-by-step excavation and supporting process was studied. Through the contrast testing with engineering examples, the rationality of this method was verified. The preliminary view to the composite soil-nailing design was proposed.

Abstract:The paper summarized the damage causes of loess foundation pit, and took the example of a retaining project to sum up the geological situation of construction and the retaining methods. Based on the foundation pit damage model, the stability computation was made and designing parameters were adjusted to determine the final scheme. The retaining scheme was introduced including the application of composite soil-nail technology and monitoring on the foundation pit deformation. The construction experience was also presented.

Abstract:Pile bottom grouting for bored pile means grouting cement slurry into the sediment and surrounding soil mass to largely increase their strength by fully filling the soil pore of the sediment at the pile tip and the soil mass to a certain range. By the physical and chemical effect, the strength was greatly enhanced to increase the vertical bearing capacity of single pile. Based on the construction practice of pile bottom grouting for bored pile of high speed railway, the paper introduced two kinds of grouting process and elucidated the importance of improving working efficiency, ensuring grouting quality and the implementation of key technical measures.

Abstract:Because large amount of water in the fourth aquifer of a coal mine in Huaibei, water was introduced into the coalface through F5 fault with serious influence to the production. High concentration chemical slurry was developed to solve the problem and restart mining by borehole grouting with good effect.

Abstract:The paper briefly analyzed the hydrogeology conditions and water inrushing factors, and the water-proof plan was established. The division of grouting section, slurry matching ratio in the water-proof grouting procedure and grouting ending standard were discussed.

Abstract:Backfill drilling is a widely adopted high efficiency mining method in modern mine, borehole backfilling is the key in backfilling system. Beside the physical property of medium transported, the mechanical property of the system and the material property of pipeline, the construction quality such as borehole deviation and some others are the decisive factors to service life of the backfilling borehole. The filling times line is main basis for design of backfill drilling hole, the construction method and process quality control are the key to ensure the quality. Based on the analysis on the factors affected on service life of backfill drilling hole and the construction difficulties, the paper summed up and introduced the construction method of backfill drilling hole and the measures for quality control.

Abstract:The pressure-dispersing anchor cable is a new type of single-hole composite anchorage system developed in recent years. Several unit cells are set in the same hole, each unit cell with different free length and anchor cable length. By the preliminary compensate tension, the concentration tensile of cable are divided into several small dispersive pressure with equal load value, which respectively acts on cable segment of each unit anchorage. With the engineering practice of slope treatment of K17+440~695 subgrade of 330 national highway, this paper discusses the construction technology of pressure dispersion pre-stressing cable and some key points which should be paid attention in the construction and engineering operation.

Abstract:To solve the difficulties of borehole completion in high slope anchor cable drilling construction for Futang hydropower plant, by the laboratory experimental study, the quick setting slurry with sulpho-aluminate cement as main agent adding special early strength agent and retarder was taken, which greatly shortened the hole cleaning and stay setting time after grouting for wall consolidation, improved the construction efficiency of anchor cable boring. The paper introduced the testing process, testing results, engineering application and the effects in detail.

Abstract:The foundation of Meizizhou open excavation section mainly consisted of approach channel and shield excavation well. Due to the large-scale excavation, abundant groundwater and complex geological conditions, dewatering in foundation pit became one of many key technologies. Because of the simple circumjacent environment, the scheme of dewatering in foundation pit was designed based on the pumping test. It was proved that the scheme was rational and feasible without unfavorable influence to the environment.

Abstract:In recent years, under-balanced drilling (UBD) and managed pressure drilling (MPD) have been rapidly developed thanks to their contributions to penetration rate improvement and effective reductions in both the occurrence of down-hole problems and non-productive time. At present, a considerable number of industry standards have been made for the above two techniques in China and abroad. Starting from oil industry standards, IADC standards and API standards, the paper focused on the discussion on the current situation of standards of UBD and MPD, studied the main contents in the future standards of managed pressure drilling in China.