Abstract:此次南海可燃冰试采工程作业区位于珠海市东南320km的神狐海域。3月28日第一口试开采井开钻，5月10日下午14时52分点火成功，从水深1266m海底以下203～277m的可燃冰矿藏开采出天然气。到5月18日上午10时，连续产气近8天，平均日产超过1.6万m3，超额完成“日产万方、持续一周”预定目标。

Abstract:This paper briefly describes the general situation of coal mine survey project in Daxueshan mining block (in the east part) of Yunlian mining area in Sichuan, including the project background and the directional hole design; mainly introduces the technical route, program and technical points, as well as the drilling effects, economic benefits and achievements obtained by cabled directional drilling. With XY-2000 spindle type hydraulic drilling machine, BW-320/10 mud pump, HC wireline coring pipe, ADST inclinometer putting through the cable swivel for measuring while drilling, the controlled directional hole was constructed by whipstocking with screw motor BHA. In 2 ultradeep holes of more than 1000m in depth, the total footage was 7378m with 29 whipstockings. The drilling trajectory was basically controlled to reach the geological target. In the construction, the selection of the bent joint angle of screw drill tools for directional drilling and the decision of bending strength suitable to wireline drill pipe were explored.

Abstract:Based on the analysis on the technical difficulties of L-type CBM horizontal wells in Shanxi, the corresponding technical countermeasures are explored, 2 build-up guidance models of landing and horizontal sections are established to form the geo-steering technical process mainly in 4 aspects of marker beds division and correlation, stratigraphic dip calculation, geological modeling and real-time trajectory control for L-type CBM horizontal wells. The successful application of this technology in T-P05 well not only enriched the contents and methods of geo-steering technology for CBM horizontal wells, but also further verify its good feasibility and application prospect, this technology is worth promoting and applying in L-type CBM horizontal wells in Linfen block.

Abstract:There are abundant geothermal resources in Fengheying which is located at the depression of Central Hebei, and the hot water reservoir is mainly JXW, belongs to carbonate crack and karst reservoirs. There are accidents such as leakage in hot water reservoir, clay swelling and collapse in the drilling process. Based on the analysis on the geological characteristics of the reservoir, the performance evaluation is made on the drilling fluid system. The experiment shows that the original drilling fluid system had poor wall building and leakage blocking properties. According to the geological characteristics of the reservoir and the mechanism of accidents, the performance of the original drilling fluid is optimized. By adding 5% superfine calcium carbonate and 5% potassium chloride into the original drilling fluid system, the performance of new drilling fluid is greatly improved with good rheology, strong inhibition, good blocking capacity and low filtration. The damage to Fengheying geothermal reservoir can be reduced by the optimized drilling fluid system.

Abstract:Combined with the construction example of Baijiatuan monitoring well of Beijing seismic station, the paper introduced a set of construction technical method which is suitable for boreholes with special requirements in complicated formations, such as unconsolidated layers, cracks and karst caves. The study was made on borehole design, drilling methods, drilling tool gradation selection, wall protection and leakage plugging technologies. Based on the previous drilling experience, drilling technical measures and drilling construction quality control measures for complicated formations were put forward, which can be useful reference for subsequent similar drilling construction.

Abstract:In view of the special requirements for cementing slurry in natural gas hydrate drilling, a new low-temperature and low-density cementing slurry formula was obtained with a number of experiments, the composition is 100% class-G oil well cement + 15% floating beads + 10%～15% micro silicon + 8% superfine slag + 1% defoaming agent + 0.5% fluid loss additive + 2.5% dispersant + 2% silane coupling agent + 5.6%～6% sodium metasilicate anhydrous + 8%～8.5% calcium chloride + 0.3% triethanolamine + 1% sodium chloride with 70% water-solid ratio. The slurry system can meet the cementing requirements of natural gas hydrate drilling in density, thickening time, compressive strength, rheology and bleeding at low temperature.

Abstract:Xinjiang Baiyanghe mining area is the first case of CBM development and utilization demonstration project in Fukang of Xinjiang, mountains and hills there make complicated topography with geological characteristics of high strata dip, multiple and large thickness of coal seams. Therefore, cluster wells are mainly planned in this area and the directional drilling technology is widely applied. This paper mainly analyzes the influence of well bore quality on the eccentric abrasion of tube and rod based on the drainage and production situation of existing wells in the demonstration project, and studies the directional drilling technology in this area in bottom-hole assembly and directional drilling technique optimization. Some problems in the application of directional drilling technology are discussed, which can provide technical basis for the future application of this technology in this area.

Abstract:In view of the serious casing damage in the mudstone interlayer and near the fault of complex Dongxin fault block reservoir, the casing damage mechanism is studied. The studies demonstrate that the main causes of the casing damage in the mudstone interlayer and near the fault are the abnormal in-situ stress there. Therefore, considering casing damage caused by the abnormal stress and non-uniform stress in these 2 stratigraphic sections, the optimization design method of casing strength is put forward based on the in-situ stress.

Abstract:With the gradually increasing development of deep geothermal reservoir in Tianjin area, it becomes more difficult for geothermal well drilling construction as serious leakage formations should be drilled through. Therefore, a set of air-lift reverse circulation drilling system with suspension type independent inner pipe is developed. In combination with the engineering examples of 2 geothermal wells in Tianjin area, the paper introduces this drilling system and analyzes the application effects in deep geothermal wells construction.

Abstract:With the continuous development of oil industry and the continuous widening of the exploration and development field in the world, the direction of exploration and development has gradually transformed to“exploring deep deposit”. The increase of the proportion of high-risk wells, deep wells and ultra-deep wells has put forward higher requirements for drilling technology and drilling fluid technology. Especially since 2014, the drilling environment of Dongsheng gas field changed significantly, due to the application and extension of drilling fluid recovery technology, a lot of used drilling fluid is involved in the circulation after simple treatment, large amount of submicron in such drilling fluid makes the maintenance and treatment difficult. For infill wells construction in old blocks, especially the exploited blocks, the permeability of drilling fluid during the pre-drilling process reduced the mechanical strength of strata rocks and changed the stress distribution of rocks, which makes the formation pressure can not be accurately predicted on the basis of the original geological data, the borehole instability problem is more prominent. Therefore, scientific management and fine management are also necessary for drilling construction, and simulation analysis is more necessary to accurately determine the performance range of drilling fluid for wall stability. The paper discusses the borehole instability of Dongsheng gas field in recent 2 years, a set of borehole stability technology is formed by the combination of drilling fluid and engineering measures to deal with the increasingly complicated borehole conditions.

Abstract:Annular gas channeling is a potential problem in almost all natural gas well cementing. Sebei natural gas field is a middle-shallow depth gas field of the Quaternary with poor diagenesis and strong shale hydration & dispersion, strong pressure sensitivity and water sensitivity; in long gas well segment, gas layer and water layer are interbedding with multiple thin gas layers; the low compressive strength of formation rock leads to very low second interface bonding strength of cement ring, it is difficult to improve the second interface quality, gas channeling, water channeling and interstratified channeling are easy to occur. Therefore, how to improve the sealing of the annular space, improve the cementing quality and ensure the integrity of the wellboe becomes a problem that needs to be solved. In view of the special geological characteristics of the gas field, the factors affecting cementing quality are analyzed and the limitation for the application of cementing technology, anti-channeling slurry system and technological measures are studied and ECP is selected to deal with the annual channeling. The analysis results show that ECP can not only effectively prevent gas channeling cement channeling, but also can improve cementing quality and optimize casing program to ensure gas well safety and prolong service life. The application of ECP for gas channeling prevention and cementing quality improvement in Sebei gas field drill is practical.

Abstract:Leakage plugging in Ordovician limestone cave has been difficult, as for the large leakage channel dimension and the slurry retention difficulty, the plugging technology of chemical consolidation with positive charges has excellent properties such as good retention, high strength and micro expansion. The chemical consolidation plugging agent contains positive charges, which can produce electric adsorption with the negative charges on the surface of leakage channel to increase retention ability; the strength of cured consolidating material can reach up to 17MPa in 48h, and the consolidating material has micro expansive function, the expansive ability can reach 3.33%, the leakage channel can be completely filled and plugged. The thickening time can be adjusted according to the underground construction situation. The chemical consolidation plugging technology was applied in well TP187 in Ordovician limestone cave, where the leakage rate was reduced from total loss to 1～2m3/10min in 3 times of plugging, which met the requirements of continuous drilling. Chemical consolidation plugging technology is effective in cave section leakage.

Abstract:The geological situation is complicated in Banchang polymetallic mining area. The fracture development of the upper part leads to the common occurrence of well leakage, collapse and shrinkage often occur because of strong water-sensitive of epidote and chlorite in middle formation. It is determined to use low solid plant glue drilling mud system in upper part; and the approximate adding amouts of plant glue, potassium humate and potassium polyacrylate as well as the influence on drilling mud performance are made clear by series of experiments; at the lower part, on the basis of plant glue, calcium treatment drilling mud was used to enhance the inhibition, increase adding amount of plant glue(CL) and asphalt powder(FT) in order to improve cementing ability and sealing ability of mud. The mud schemes have been succssefully applied in ZK1724 of Banchang polymentallic mining area, which created favorable conditions for complex formations in this area.

Abstract:Shale has strong water sensitivity, borehole instability of over-diameter and diameter reducing caused by collapse and spall often happen in shale gas exploration drilling. Diamond wire-line coring technology was adopted in well Luodi-1 with the completed depth of 1501.06m, core recovery and hole deviation are all in accordance with geological design requirements. This paper summarizes the drilling equipments, wellbore structure and construction difficulties of well Luodi-1 in order to provide reference for the construction of shale gas investigation well in the future.

Abstract:The technical requirements of drilling fluid rheology test instruments under new drilling conditions are analyzed in this paper. The development and application of popular imported high temperature and high pressure rheometer are presented. This paper also introduces the research progress, main functions, technical advantages and application fields of the ultra-high pressure high-temperature and low-temperature drilling fluid rheometer Explore 97, which is independently developed in China, and takes it comparing with Fann iX77 rheometer in technology.

Abstract:Reverse circulation (RC) sample drilling is another technical revolution in drilling technology, which has been widely applied in western counties for its efficiency, low cost and high adaptability. In recent years, RC drilling has also been paid more and more attention in China with more and more application. Sampling technology is an important part of RC drilling, comparing with some foreign countries, the sampling technology is still backward in China. The double-outlet cyclone sampler is an improved device on the basis of a single outlet cyclone sampler; the valve is shared by 2 outlets, one opening while another closing. Samples taking are in turn at 2 outlets by the valve switching to avoid samples missing in continuous drilling and reduce the dust pollution in the sampling process. Through the application in RC drilling test in Kalatage equipped exploration mining area, it is proved that this double-outlet cyclone sampler has great superiority in preventing samples omission, reducing environmental pollution and facilitating sampling operation.

Abstract:In Luanjiahe gold exploration area, XD-30DB drill rig was introduced to carry out wire-line coring drilling construction for deep geological hole. Mainly through the application of electric frequency conversion top drive drilling machine, this paper optimizes and sums up its effect, performance and working methods in the drilling process, and puts forward some suggestions for the improvement.

Abstract:Since PDC（Polycrystalline Diamond Compact）was developed successfully in 1980s, PDC drill bit has been widely applied in petroleum drilling and geological exploration in many countries due to its good penetration ability and wear resistance, and very good results have been obtained. However, how to further improve its technical and economic indicators in drilling engineering becomes a very urgent problem. Russian doctor of technical sciences professor Скоромных В. В. and some others have studied this problem for many years and put forward an idea of stabilized mode of rock fragmentation, that is a rock fragmentation method under the condition that the resultant force R held together by axial load & torque sheering force and the cutting surface are perpendicular to the angle with the constant cutting depth. On this basis, some suggestions on PDC bit design are presented.

Abstract:Numerical simulation study on geothermal field of ground water heat pump system is of great significance to the development and utilization of shallow geothermal energy. By building hydro-thermal coupling model of ground water heat pump system by TOUGH2, the change trend of geothermal field and the temperature change of pumping-recharging wells in the study area for years are simulated. The results show that a large amount of cold accumulation appeared in some component parts of ground water heat pump system after 10 years’ operation, which affects heating temperature. Based on the above results and combined with the field site conditions, the solar assisted heat source system is adopted for the system strengthening design aiming at the cold accumulation, the change trend of geothermal field for years in the strengthened system is simulated, and the results show that the solar assisted heat source system can effectively improve the heating temperature.

Abstract:Based on the Mindlin elastic displacement solution and combined with finite element numerical example, the analysis is made on the vertical deformation difference of deep plate test and single pile vertical compressive static load test under the same load condition. The ratio of vertical displacement resulted from these 2 tests decreases with the increase of pile diameter, and the ratio is 3.2～4.6 while the conventional pile diameters are within the range of 0.8～2.0m. The engineering example shows that the ratio of the both can be 4.5～7.2 times. Therefore, single pile vertical load-bearing potential can not be fully exploited in the deep plate loading test and the test results can not truly reflect the single pile vertical load-bearing performance. The bearing capacity of pile tip should be determined by single pile vertical compressive static load test rather than deep plate loading test.

Abstract:The design and construction of directional blasting demolition of a 120m high chimney in Changzhou is introduced, where existing hot gas pipeline, workshop, communication tower and high voltage line and so on. The environment of blasting area is complex and near to the protection objects, it is difficult to control the collapse vibration and flyrocks. According to the features of chimney structure and the site actual situation, good blasting results are achieved by rising the blasting cut height, selecting reasonable design scheme and parameters and adopting pertinence safety precautions measures of damping ditch, damping earth embankment and cut-off wall.