Abstract:Accurate prediction of rate of penetration （ROP） in deep geological drilling process can help to improve drilling efficiency and reduce drilling costs， which can provide key technical support for safety and efficient deep geological drilling construction. In this paper， a dynamic prediction method of ROP in deep geological drilling process based on regional multi-well data optimization and model pre-training is proposed. First， the deep geological drilling data warehouse is designed by selecting lithology identification software， drilling process intelligent monitoring cloud platform， and geological cloud system as data sources. Secondly， the regional multi-well data optimization technique is used to select the matching data with the target well in the data warehouse， and the ROP model is pre-trained on this basis. Finally， the ROP prediction model is dynamically updated through combining the actual drilling data of deep geological drilling process， and introducing techniques such as the wavelet filtering， extreme learning machine， and incremental learning strategy. The experimental comparison results verify that the proposed method has strong ROP prediction performance and generalization capability.

Abstract:It is planning to drill an extremely deep hole with depth of 13000m in China that has great significance. In deep drilling， particularly in superdeep drilling it is a difficult problem to transfer the bottom hole drilling parameters to the surface in time and correctly and to adjust and control them so that the normal drilling and good technical and economic results can be guaranteed. Russian experts propose a combination link channel and that has definite reference value probably. It is very important to have an automatic control system to solve the problem of how to adjust and control the bottom hole drilling fluid pressure in order to guarantee the normal drilling and prevent accident and how to resolve the response lateness of signal in the link channel. Russian scientists have done a lot of work in these fields and got a definite success and that deserves our attention.

Abstract:Scientific drilling is an important technical means for obtaining underground physical data， anaylzing underground structures， and verifying important geological theories. The key underground instrument is an important basic guarantee for ensuring the smooth implementation of drilling projects. However， during the myriametric scientific drilling process， the requirements of underground working conditions and craftwork such as high temperature， high pressure， long drilling period， and large specification parameters seriously challenge the working performance of underground instrument. To the end， this paper analyses the structural characteristics and failure reasons of key underground instrument such as drill string， downhole mud motor， and auxiliary synergistic tools under the myriametric drilling working condition， and proposes corresponding measures on optimizing the structure of drill pipe joint， designing metal gear drill， improving the structure of hydraulic oscillator and injection-type torque thruster， and materials selection and setting up surface strengthening techniques， which can provide technical reserves for earth interior detection.

Abstract:Currently in the field of deep geological core drilling，wire-line core drilling is the most commonly used drilling technology. Owing to annular size of wire-line core drilling is smaller， have no choice but to adopt the method of enlarging the drill bit， solve problems such as high pump pressure and high excited pressure causing hole-wall instability. In deep hole construction， the problem of annular clearance can be solved by increasing the drill bit to the upper caliber without lowering the upper casing. There is also an additional level of spare caliber. This article analyzes the drill pipe capacity of wire-line coring drilling， The theoretical basis for cross bore wire-line coring tools is proposed. The drilling tool has been designed and processed in a complete set and continuously improved in application practice. It provides great help for drilling structure design and complex formation drilling in the field of deep geological core drilling， Achieve good application results. In order to meet the requirements of long hole coring in geothermal drilling， a design scheme for large diameter wire-line coring tools was proposed， further expanding the scope of use of wire-line coring.

Abstract:The 3000m scientific deep borehole in southern Hunan is the first 3000m geological core drilling extra-deep hole in Hunan province. It is located in the transition zone of complex folds， and many complex formations， such as borehole shrinkage in clay， total hole leakage， water-sensitive collapse shrinkage and vertical joint development collapse， have been drilled， resulting in many down-hole incidents. In view of the main down-hole incidents such as bit sticking and hole collapse， the drilling structure， drilling fluid system and drill assembly were optimized， and various technical measures were adopted to effectively deal with various difficulties in drilling， such as sidetracking， circulating sand bailing， wall protection with film forming drilling fluid and wall protection with cement slurry. The final hole depth is 3008.93m， and the average core recovery rate is 98.16%， which has achieved the expected goal. Qualified geological boreholes and physical core data are provided for the theoretical study of deep mineral mineralization and resource exploration in this area.

Abstract:The 3000m deep scientific drilling of west Sichuan Jiajika lithium mine is located in the Songpan-Garze orogenic belt in the middle and north of the Qinghai-Tibet Plateau. Key technology such as wireline coring drilling and wireline coring hydraulic percussive rotary drilling， diamond bit optimization in hard rock formation， lengthened internal coating inner pipe and improved fishing device， and environment-friendly solid-free polymer flushing fluid technology are adopted. The final hole depth is 3211.21 meters， creating a new record for the depth of small caliber solid mineral exploration holes in plateau areas and a national record for the efficiency of drilling construction of the same type at that time. It has important scientific significance for the theoretical innovation of the metallogenic model and mechanism of the Jiajika pegmatite lithium deposit， and also provides a reference for the deep drilling construction in the plateau area.

Abstract:With the application of directional drilling technology more and more widely， the control technology of borehole trajectory becomes particularly important. In order to study the natural bending law of the borehole， find out the change trend of the vertex angle and azimuth angle， and then predict the change of the borehole trajectory to be drilled， use SPSS software to conduct multiple equation regression statistical analysis on the borehole inclinometer data of Anhui No.1 mining area. On the basis of considering the influence of the hole depth and the spatial location information of the hole opening point （x、y、z coordinates） on the vertex angle and azimuth angle， a quaternion octave polynomial regression equation is established， and the average angle full distance method is used to compare the spatial location of the regression fitting borehole axis with the actual borehole spatial location. The results show that after linear processing of the original drilling data， a good result can be obtained by using quaternion octave polynomial regression. If the regression is carried out after classification according to the different occurrence of the stratum where the drilling is located， the fitting degree will be further improved. The regression equation with high fitting degree can be used to predict the natural bending trajectory of the borehole in the non-perforated area， which also plays a good role in controlling the borehole trajectory in the project construction， and can better guide the project construction.

Abstract:During the investigation and evaluation of Uranium deposits in Shiquantan area of Qaidam Basin，the formation pressure anomaly was encountered. The formation pressure coefficient of 0~600m is 1.25~1.4. The formation is easily soluble with a high salt content of up to 1.025%. Accidents such as stuck and collapse usually happened during the drlling process as drilling information about this area is less. In this paper， a set of anti-salt and anti-collapse flushing fluid system suitable for the strata in this area is proposed by analyzing the lithological characteristics of the strata in this area， and preferentially selecting the corresponding slurry-making clay and treatment agent for the flushing fluid. As a result， this systerm has good anti-salt and anti-collapse performance， mainly showing as follows： the apparent viscosity 38MPa·s， the dynamic shear force is 16.4Pa， the API filter vector is 4~5mL， the mud skin is thin and dense with the thickness of 0.3~0.4mm which has good wall protection effect. It effectively solved the problems such as shrinkage in salt-gypsum layers， hole collapse and destabilization of flushing fluid under abnormal conditions of high pressure in this area. As a result， the average monthly efficiency is increased from 729.76m to 1378.78m， the hole expansion rate is reduced from 130% to 19.4%， and the cost of mud material and water is reduced from 57.91RMB/m to 38.92RMB/m. Good economic benefits have been achieved in practical application in the field which make it has the value of popularization and application.

Abstract:Compared with the traditional drilling technology， air reverse circulation drilling has the advantages of low cost， fast drilling speed， low site requirements， reliable and non-pollution samples. Because it takes compressed air as the main circulating medium， it is easy to cause blockage when meets water and ice. Therefore， it has been a difficult problem to be applied in the ultra-high altitude area with complex environment such as thin air， thick permafrost and abundant groundwater. In order to verify the feasibility of air reverse circulation drilling technology applied in the complex environment， based on the air reverse circulation drilling project of Julong copper mine in the Tibet autonomous region， this paper has successfully developed a complete set of construction technology to overcome complex environmental factors through the selection of high-power equipment， the improvement of waterproof technology and the application of anti-freezing materials. As a result， its comprehensive efficiency is similar to that of the plain area， and the air reverse circulation drilling technology can be applied to the ultra-high altitude area is proved.

Abstract:In order to research the impact motion law of the dual-fluid rotary valve impactor in rotary percussive drilling， and optimize its performance parameters， through the analysis of its forces in the phases of stroke and return， the finite difference method is used to create the mathematical model of the rotary valve piston movement， and a simulation computer program compiled with MATLAB software is applied to simulation of the dynamic process of the rotary valve piston to obtain the optimal impact performance parameters of the dual-fluid powered rotary valve drilling impactor. At the same time， the influence of the difference in the area between the upper and lower chambers of the impactor， and the flow rate and pressure drop of the oil pressure system on the impact performance of the dual-fluid powered rotary valve drilling impactor is studied， and the orthogonal analysis test for impact energy， impact frequency and impact power is designed. The results are optimized by Design-Expert software to improve the working performance of the impactor. The results show that the piston rod diameter and pressure drop have prominent effects on the impactor performance， while the flow rate has little effect on the impactor performance. After optimization， the impact energy， impact frequency and impact power are increased by 21.88%，12.9% and 37.6% respectively. The research has guiding significance to the design and application of hydraulic impactors.

Abstract:Closed pressure maintaining coring is a special coring technique that can maintain or approach formation pressure， allowing fluid and gas in the core to remain in their original state.This technology is of great significance for correctly understanding geological conditions， calculating recoverable reserves of oil fields， analyzing the mechanism of shale gas and coalbed gas reservoirs， and formulating exploration and development plans.TKP194-80 type sealed pressure maintaining coring tool is developed， which adopts key technologies such as large bore high pressure ball valve sealing， sealing fluid plugging， hydraulic differential migration， piston pressure compensation， and is equipped with core post-processing processes such as core freezing， cutting， and gas gathering. The outer diameter of the drill bit is 215mm， the pressure maintaining capacity is 50MPa， and the core diameter is 80mm.The application of pressure retaining coring was carried out in a coalbed methane resource geological exploration well in Jinzhong， Shanxi province. A total of 8 pressure retaining coring barrels were carried out， with a total footage of 37.51m. The core recovery rate was 84.4%， and the pressure retaining success rate was 87.5%.The research results show that the coring tool has reliable pressure retaining performance， feasible technical scheme， and meets the design requirements. It can provide technical equipment support for the exploration and development of conventional and unconventional oil and gas reservoirs.

Abstract:Completely weathered argillaceous limestone has complex composition and special structure. When countered water， it is easy to be soften and distingrate， and its strength is rapidly reduced， which is very easy to induce various engineering geological disasters. Taking the completely weathered argillaceous limestone in Dajiangou area of Jinan as the research object， the engineering geological characteristics of the completely weathered argillaceous limestone are studied from the physical， mechanical and hydraulic aspects through the combination of field investigation and laboratory test， moreover， the stability of the hole wall during the drilling process is evaluated based on the discrete element software PFC. The correlation between the stress in the hole and the grouting pressure is obtained， which provides reasonable suggestions and references for the future pile foundation construction. The results show that the completely weathered argillaceous limestone has poor water resistance and is easy to disintegrate， and the water content has a significant impact on the disintegration rate. With the increase of water content， the shear strength of completely weathered argillaceous limestone decreases exponentially， and the deterioration of strength is obvious. Under dynamic disturbance， the internal unit of completely weathered argillaceous limestone is seriously damaged. It is recommended to set the mud pressure at 0.3MP， which can generate relatively obvious normal contact force on the hole wall without causing soil damage， and provide better support for the stability of the hole wall.

Abstract:This paper takes a deep fill slop in Xianning Hubei as the construction background. The numerical simulation software—Geo-studio was adopted to analyze the influence of rainfall-surcharge coupling effect on the stability of deep fill slope， the pore water pressure distribution inside the slope and the influence of constant rainfall and surcharge at the top of slope on the stability coefficient were also analyzed. The results showed that the original slope was in metastable state under the condition of rainfall and surcharge at the top of slope， the stability coefficient decreased with the rainfalls time， compared with the constant rainfall， the surcharge load had a greater impact on the stability of fill slope. To the end， a reinforcement scheme of a slope scouring and load reduction and waterproof surface was proposed. The numerical simulation results confirmed the feasibility of the scheme， which meet the requirement of the construction， meanwihile， the rationality and validity of the simulation results were verified.

Abstract:In practical construction， there are usually some foundation pits with large scale， long construction period and are overwintering. Therefore， the work of proper cold-insulation and protection needs to be done. Based on a deep foundation pit project of a building in Ulaanbaatar， the capital of Mongolia， this paper studies the cold-insulation and protection technology for safety wintering of deep foundation pits. B2 grade polystyrene board is used to insulate and prevent freezing of the soil at the bottom of the pit. Greenhouse was built to keep the leakage area on the side wall of the foundation pit warm. Measures of electric heat tracing and insulation with rock wool are adopted to ensure normal dewatering of the foundation pit. The actual construction situation confirmed the effectiveness of the above technology， which can provide reference for the insulation and protection of safe overwintering of foundation pit projects in the future.

Abstract:In order to know more accurately the rock mechanical properties of hot-dry rock reservoir under high temperature， and further guide the drilling work of hot-dry rock， the real-time Brazilian splitting test， shear test and uniaxial compression test under high temperature were carried out in laboratory. In a single test， rock samples taken from the same borehole and the same depth were loaded at a rate of 0.1mm/min by setting the temperature and holding temperature time using a high-low temperature chamber， to reduce the adverse influence of the discretization of rock macro-mechanical properties and the deviation of test process on the test results. The samples are monzonitic granite taken from the Well LGZK1 in the Wendeng-Rongcheng-Weihai area of Shandong province. Through obtaining the maximum load and deformation data of the samples at failure， the mechanical properties such as tensile strength， shear strength， compressive strength and elastic modulus are calculated， and the failure mechanism and strength difference of the rock under real-time high temperature are analyzed. As a result， the shearing strength and uniaxial compressive strength of granite increased and the tensile strength decreased below 200 °C. While the shear strength and uniaxial compressive strength of the granite decreased and the tensile strength continuously decreased with the increase of temperature. The increase of temperature and stress will increase the hardness and plasticity of the rock. It provides basic parameters for the study of rock mechanical properties of the high heat flow granite， and also provides a reference for the selection of rock-crushing tools， drilling technology and wellbore stability in the exploration and development of high heat flow granite type hot-dry rock resources.

Abstract:Compound cone single cone bit is a new type of single cone bit based on spherical single cone bit. Its unique rock breaking method can improve the bit efficiency. The field test found that the cutting teeth and diameter retaining teeth on the small end of the drill bit tooth wheel were seriously worn， and the cutting teeth and diameter retaining teeth at the large end of the tooth wheel were basically not worn， resulting in a decrease in the drilling speed of the entire drill bit. In order to find out the reasons for the uneven wear of the drill bit， the tooth load of each ring gear of the drill bit was tested by finite element analysis method， and the cutting trajectory shape of each ring gear tooth and the contact time between the tooth and the rock were analyzed. The results showed that the tooth load at the large end of the tooth wheel was greater than that at the small end of the tooth wheel， but the contact time between the teeth at the small end of the wheel and the rock was longer. Based on the analysis of tooth rock breaking time and tooth axial load， the wear of No.⑥ ring gear teeth should theoretically be minimal. The field test results show that not only the wear of the No.6 ring gear is small， but also the wear of the No.①，④ and ⑤ ring gear is smaller. The diameter retaining teeth on the side of the drill bit are seriously worn， and the wear of the ring gear No.⑦ and ⑧ is serious， it can be determined that the drill bit is tilted to the side of the well wall during drilling， resulting in serious wear of the cutting teeth and diameter retaining teeth on the side of the drill bit.

Abstract:In response to the characteristics of Daqing Gulong Shale-type reservoirs such as rich phyllite， low horizontal permeability and inability to flow in the vertical direction， it is necessary to increase the pure pressure by temporary plugging steering fracturing technology. The degree of fracture complexity is further increased using the temporary particles to seal the borehole and force the fracturing fluid to turn. This paper analyzes the force and pressure changes of temporary plugging particles in the wellbore and near the shot-holes before and after temporary plugging， proposes the equation of motion of the temporary plugging particles， establishs two parameters to evaluate the setting effect of temporary plugging particles， sets the standard to evaluate the temporary plugging steering， develops the dosage design method of temporary plugging particles， and studies the sealing effect of temporary plugging particles in the process of fracturing construction for horizontal wells in shale oil test area. The field test results show that the efficiency of temporary plugging reached 66.7%， the setting efficiency reached 74% and the temporary plugging particle efficiency reached 34%. The fracture initiation position or extensive direction is obviously different after temporary plugging， the shot-hole sealing is effective， and the purpose of fracture steering is realized， which provides theoretical support for the future work of fracturing for shale oil reservoirs.

Abstract:Aiming at the problems of long horizontal section， complex wellbore conditions， difficulty in casing centralization， low displacement efficiency， and high performance requirements of cement system which restrict the improvement of cementing quality in shale oil horizontal wells， research on the collaborative optimization technology of drilling parameters and drill string assembly was carried out to meet the requirements of improving cementing quality for wellbore cleaning. In addition， the ideal casing centralization is designed by the simulation of displacement efficiency， and the integral stamping screw semi-rigid centralizer and the water displacement prestressed cementing technology are also optimized. Furthermore， the strength of cement paste is improved based on the toughness modification technology. The hydraulic fracturing requirements of shale oil wells can be met through ruducing the Young''s modulus and using the improved cement paste. All these work ensured the cementing quality of Well GY5-1-4H， so as to provide a worth considering key technology for long horizontal well cementing.

Abstract:Well D05 is a geothermal exploration well in Xiong’an New Area with the total depth of 4014.42 m， and two thermal reservoirs were revealed named Wumishan Formation and Gaoyuzhuang Formation. The situation of serious wear and short service life of bit appeared when drilling in the quartz-rich chert dolomite strata in Gaoyuzhuang Formation. Therefore， the exploration of drill bit was made through the analytical study and practice optimization. As a result， a kind of cone bit suitable for ?215.9mm well diameter in quartz-rich chert dolomite strata was explored， and the problem of bit wear and drilling efficiency were balanced. The drilling task of ?215.9mm well diameter in the third spud of Well D05 was completed smoothly by the use of this bit. The successful application provides a reference scheme for bit usage in similar strata， enriches the deep geothermal drilling technology and provides technical support for the development of deep geothermal drilling.

Abstract:In recent years， people have paid more and more attention to the development of medium-deep sandstone geothermal resources， and centralized exploitation has gradually become the norm. In the deployment process of centralized sandstone geothermal wells， well spacing and well pattern not only determine the temperature and water level changes of geothermal wells after many years， but also affect the life and economy of geothermal projects. This paper takes the geothermal heating project with an area of 2.3×10⁶m² in Jidong Caofeidian Newtown as an example， the optimization of centralized sandstone geothermal exploitation well pattern is studied. On the basis of geothermal exploration in the study area， the exploitation volume of geothermal wells is 100m³/h and the reinjection volume is 80m³/h. Numerical modeling is used to optimize the well spacing of geothermal production and irrigation wells to 450m， and the well pattern of geothermal production and irrigation wells is arranged in staggered rows. Multi-well pilot test is used to verify the rationality of the production and reinjection volumn of the geothermal well， and the geothermal well production and irrigation operation and maintenance system is formulated to achieve 100% natural reinjection. The water level and temperature changes for many years of the thermal reservoir seepage field are predicted by modeling the production data of the well group. It can provide technical support for large-scale geothermal resource development.

Abstract:The emergence of magnetic guided butted well technology has greatly improved the connectivity of docking. Now the technology is widely used in the mining of natural alkali and other minerals. With the continuous development of this technology， as an excellent representative of the underground “thread the needle” navigation tool—SmartMag drilling target-hitting guide system， with its excellent measurement accuracy， stability and reliability， has made hundreds of good achievements in the water solution mining butted wells at home and abroad.From the perspective of science popularization， this paper introduces the necessity of downhole docking navigation， the composition and principle of SmartMag system， the development process of SmartMag system and the achievements made in recent years， so as to improve everyone’s understanding of the SmartMag system， achieve the purpose of mutual exchange and mutual promotion， and finally promote the continuous development of the technology and the continuous expansion of the application field of the active magnetic measurement system represented by SmartMag system.