Abstract:In the strategic action of ore prospecting breakthrough， the drilling depth is constantly increasing， and intelligent working condition recognition has become a necessary measure for safe， efficient and low-cost drilling. Its steps include signal acquisition， feature extraction， state recognition and diagnosis decision， among which the establishment of accurate and reliable in-hole accident discrimination criterion is the difficulty and core of state recognition and diagnosis decision. Firstly， based on the theoretical knowledge and engineering practice experience of in-hole accidents， this paper divides the six types of accidents in drilling holes into buried drilling， stuck drilling， burned drilling， broken drilling， hole leakage and hole overflow， and summarizes their occurrence symptoms. The characteristics and change trend expression of real-time drilling signal parameters are analyzed in detail. On this basis， the relative mean， standard deviation， mean slope， standard deviation slope and their thresholds of six characteristic parameters， including pump pressure， drilling speed， torque， rotation speed， overhead weight and outlet flow， are proposed to characterize the change of each parameter. Finally， the accident discrimination criterion is established in the form of matrix. The discrimination criterion has strong theoretical and practical basis， and can divide the detailed drilling accident categories in actual use， which can provide a discrimination basis for subsequent software development.

Abstract:This paper mainly introduces the basic working principle， technical performance and application of hydraulic pipe cutter for small diameter drilling in geological core drilling in southern Shanxi and Beishan areas. The practice shows that compared with other types of pipe cutters， the hydraulic pipe cutter has the advantages of simple design， convenient operation and high working efficiency. It has played a huge role in the treatment of drilling stuck， buried drilling and other accidents， and has achieved good application results. At the same time， there are also some problems in the practical application of hydraulic pipe cutter， such as the welding quality of the tool head is not high， the existence of ring cutting vibration and the phenomenon of the tool head falling edge. Through the analysis and summary of the actual application， some suggestions are put forward to improve the existing problems， so as to promote the application of the equipment.

Abstract:Drilling accidents can cause serious economic losses， wasted time， and even threaten life safety. If the drilling equipment can judge the type of accident in time， the accident processing time can be shortened and the development of the situation can be contained. To solve the above problems， this paper proposes a drilling fault diagnosis model of equipment based on neural network. In order to optimize the correct rate of different neural networks in drilling accidents classification， two neural network models of BP and RBF are constructed respectively in nntool of Matlab. Through the simulation test taking the variation trend of construction parameters in a mining area as input parameters， it is found that the best performance in BP neural network is LM and BR algorithm， and the best performance of RBF neural network is PNN algorithm. All three had an accuracy rate of more than 90 percent. But BP neural network is easy to fall into local optimal with unstable performance. On the contrary， PNN neural network has no such limitation， does not require training， and the design process is simple. So PNN algorithm is more suitable for the establishment of drilling fault diagnosis model.

Abstract:The research on “Air DTH Hammer drilling technology” was carried out by the Bureau of Geology and Mineral Exploration and Development of Guizhou Province, which was a part of the scientific research project of “Application research on deep well drilling technology in Guizhou complex strata”. During the test process, some typical accidents happened, such as the hammerhead fracture, hard alloy tooth fracture, impactor blockage and blocking, mud ring wrapping, drill pipe sticking & burying and borehole bending. The causes of these typical accidents are analyzed in detail, and the systematic technical measures to avoid and solve these typical accidents have been formed. The results are proved good through field inspection and this paper gives a comprehensive elaboration on this achievement in order to provide reference for the similar construction.

Abstract:Xiangyongdi well-1 drilling engineering for the geological survey of shale gas was carried out in the Paleozoic shale gas field in the Middle Yangtze region of China, the final depth was 2,224.69m with full borehole coring, logging and well logging. This article mainly introduces the general situation of the project, the main drilling equipment, logging equipment and well logging equipment used in drilling engineering and the core drilling technology of Xiangjingdi well-1. The technical measures adopted for drilling accidents encountered in drilling construction and the drilling construction technology of shale gas survey well are discussed.

Abstract:In the drilling process of ZK1010 which is a deep exploration hole of Yuquan manganese mine in Xiushan of Chongqing, drill pipe breaking often happened. Drill pipe falling often occurred during tripping out process, which made the accidents even worse. Finally, by the use of releasing fishing spear, the drill rod breaking is successfully handled for times. The paper introduces the releasing fishing spear about its working principle and advantages.

Abstract:By the analysis on the technical problems encountered in the scientific drilling construction in Luobusha of Tibet, the paper elucidates the technical problems that are often encountered in deep drilling construction and need to be carefully considered; summed up the construction experience in complex formations and the countermeasures.

Abstract:To make the drilling process more efficient and successful against drilling complex formations while penetrating through deep thick overburden layer at Badi hydropower station over the Dadu river, 139 thick-walled casing and vegetable gum were used to improve coring quality and drilling efficiency respectively. 139 thick-walled casing can avoid frequent drilling accidents and shallow depth in casing process and is compatible with 108 casing much better than 127. It is proved that this technology can give good coring qualityand satisfy drilling efficiency with lower drilling cost and higher economic benefits.

Abstract:For 100 meter depth geological drilling in offshore sand, directly coring in non-cementing loose sandy sediments formation without casing greatly reduces labor intensity and improves working efficiency. Hole wall collapsing, difficult cuttings upward, sand gushing and drill pipe sticking are often encountered in the core drilling investigation in offshore sand of Yellow Sea. The paper summed up the drilling process technology for the well of 100 meter depth in offshore sand and the prevention measures for downhole accident.

Abstract:In the core drilling construction, downhole accident is unavoidable and the block of drill pipe, drilling tools and casing are frequently occur. Reverse thread drill pipe cannot get off the block at ideal position and the pipe cutter is commonly used to continue the construction to reduce the economic loss. A new pipe cutter was designed in the engineering practice with reliable working performance; comparing with previously used pipe cutters, it has characteristics of simple structure, easy operation, wide application range (pipe with minimum inner diameter of 60mm can be cut), high working efficiency and good generality.