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In the Upper Permian coal bearing strata of Liupanshui Coalfield, there were coal seam, shale and sandstone overlaid frequently. In order to have an overall plan and exploration on the natural gas in different reservoir and to favorably reduce the resources wasted and improve the development benefit, with the study on the lithofacies, thickness and source rock geochemistry of the coal measure gas reservoir, the reservoir physical property and the spatial occurrence law, this paper analyzed the reservoir formation potential of the coalbed methane, coal measure shale gas and the coal measure tight gas in Liupanshui Coalfield and discussed the space overlaid relationship and exploration prospects of the coal measure gas. The study results showed that within the coalfield, the coal rank of late Permian coal seam was complete, the thickness was high, the metamorphic grade was generally higher, and the gas content was good. The gross thicknesses of the shale and the sandstone were high, the organic geochemistry and reservoir physical parameters were good. The difference was high in regional and horizon distribution of different lithology, the lithological combination types varied, and the space disposition was beneficial to the development of many vertical natural gas reservoirs. The favorable exploration horizon of the coal measure shale gas was the lower section of the Longtan Formation and the favorable horizon of the coalbed methane and the coal measure tight gas was the Wangjiazhai Formation and the up section of Longtan Formation. Based on the circumstances, totally three major gas reservoir types, including the “resources and storage integration” independent coal measure shale gas reservoir, “resources and storage closed neighbor type” coal measure “three gas combined gas reservoirs” and “bottom resources and top storage type” coal measure “two gases combined gas reservoirs” were summarized and provided. The paper preliminarily concluded that Qinglong Syncline deep section would be the priority exploration zone of the coal measure shale gas, Qingshan Syncline deep section would be favorable to the co-exploration and co-mining of the coalbed methane and the coal measure shale gas, Panguan Syncline and Gemudi Syncline deep section would be favorable to the co-exploration and co-mining of the coalbed methane and the coal measure tight sandstone gas. [ABSTRACT FROM AUTHOR]

During the process of hang sidetrack drilling in open hole of multilateral horizontal wells for extracting coal-bed methane (CBM), it is very important to understand the mechanism of multilateral junctions' crushing and stabilizing under the effects of in-situ stress and drilling tools. This paper presented a dynamic explicit finite element model containing the interaction between the bit, well-bore and drilling fluid based on Lagrange explicit algorithm and triaxial compressive test data on core samples obtained from Well Z1. The dynamic process of hang sidetrack drilling in an open hole was simulated on the basis of Drucker-Prager criterion to investigate the influence of nonlinear and dynamic force from the rotary percussion of drill bit and the contact of drilling tools on the formation of branch well. The process from the start of sidetracking to the formation of branch well was defined as engraving stage which was further divided into three steps including “early”, “middle” and “last” stage. The fluctuating stress of wall rock, the way of crushing and the control condition of bit pressure for branch well's formation were obtained for these three stages.Furthermore,the paper comprehensively discusses the process and the mechanism of multilateral junctions' crushing in sidetracking under the effects of in-situ stress,drilling tools and fluid. [ABSTRACT FROM AUTHOR]

Aiming at the problems of low efficiency of coalbed methane extraction in soft and hard coal composite seam and uneven extraction in coal seam longitudinal section, etc，In order to achieve rapid and overall efficient extraction of CBM over a large area. Taking the No. 3 coal seam in Zhaozhuang field of Qinshui basin as an example, this paper analyzes the layered characteristics of soft-hard coal, optimize the local hard coal segment in the composite coal seam. and puts forward the new idea of exploiting CBM through noncementing staged fracturing horizontal wells in layered soft-hard coal seam. On the basis of fracture propagation pattern of fracturing on horizontal wells in layered soft-hard coal seam, the technical measures for the development of CBM by noncementing staged fracturing horizontal wells are investigated. The results show that there are obvious layers of soft and hard coal in No. 3 coal seam. and obvious characteristics of natural gamma and resistivity logging response in soft-hard coal. Horizontal well in hard coal fracturing can form a complex and irregular vertical fracture, which is easy to expand and extend along the roof strata with strong brittleness. Hydraulic fracturing can break both hard and soft coal seam, and can improve the fracturing effect of soft and hard coal seam. The location of horizontal wells in hard coal and fracturing construction discharge have an influence on the effect of fracture expansion, the influence degree of fracturing discharge is large and the horizontal well position is small. In view of this characteristic, four key technologies for the successful development of CBM by horizontal wells of staged fracturing are formed:(1) Optimization technology of perforation and fracturing section in horizontal well;(2) Pipeline transmission large displacement hydraulic jet anti-channeling technology; (3) Technology of slug type water carrying sand fracturing with “large displacement, large scale and medium sand ratio”; (4) Fine drainage and mining technology for simultaneous production of gas and water well separately. The practice proves that this technology can greatly increase the output of horizontal well of coalbed methane, break through the technical bottleneck of low yield of soft and hard coal composite coal seam, and provide a technical way for coalbed methane extraction and gas disaster control of soft and hard coal composite coal seam. [ABSTRACT FROM AUTHOR]

Compared with AC microgrid, DC microgrid has the advantages of few energy conversion devices, simple control structure, no consideration on eddy current and reactive power, and so on. It has become a research hotspot in the field of efficient utilization of distributed energy resources(DERs) and flexible DC distribution. Hwever, most of the research focuses on the application and development of DC microgrids in future residential and intelligent buildings, as well as the optimization and coordination of DERs in DC microgrids, which lacks in-depth research on the DC microgrid system for CBM ground extraction with the application background and self load characteristics of the energy industry. Combined with the power network for coalbed methane(CBM) ground extraction and electrical load characteristics, the DC microgrid hierarchical topology system for CBM ground extraction was proposed in this paper. In addition, the key technologies to build DC microgrid system for CBM ground extraction were summarized and analyzed, and the feasibility of implementing a DC microgrid system for CBM ground extraction was analyzed and overviewed. [ABSTRACT FROM AUTHOR]

With the constant development of production technology, the co-exploration of coal measure gas becomes possible. Since the co-exploration of coal measure gas is based on the co-existence of coal measure gas, the study on the co-existence of coal measure gas has important guiding significance to the co-exploration. Based on the study of source rock, reservoir rock and cap rock of coal measure gas in Linxing block, eastern Ordos Basin, as well as the observation of rock core and field geology trip, this paper summarizes the co-existence patterns of coal measure gas, and discusses the origin mechanism of coal measure gas in terms of sedimentation and diagenesis. Results show that No. 8+9 coal seams in Benxi formation and Nos. 4+5 coal seams in Shanxi formation are the main source rocks. Dark muddy shales have a certain capacity of hydrocarbon generation. The type of sandstone is mainly lithic sandstone, whose average porosity is 6. 2% and average permeability is 0. 14×10-15 m2, meaning it belongs to tight sandstone. Tight sandstone, shale and coal seam are cap rock to each other, which leads to 14 combination modes between any two of tight sandstone gas, gas and coalbed methane. And the composition pattern of coal measure gas can be divided into four categories. Sedimentation determines the formation of CMG and the diagenesis affects its co-existence. [ABSTRACT FROM AUTHOR]

Hydrogeological condition is one of the most important factors controlling the migration,dispersion,distribution and accumulation of coalbed methane (CBM) in coal reservoir.In this paper,the water produced from CBM wells in Gujiao mining area was monitored in terms of concentrations,water quality and salinity.Then,combined with the local gas content and the distribution characteristics of groundwater,the geological controlling mechanisms on gas distribution characteristics in different units were discussed.Results show that the main ions of produced water were Na+,HCO3- and the type was NaHCO3.The total dissolved solids (TDS) of produced water were relatively lower,which ranged from 632 to 2 512 mg/L,belonging to freshwater-saline water.The research area were divided into runoff zone,weak runoff zone and stagnant zone,and the stagnant zone according to discounted water level and TDS.The stagnant zone had the highest gas content,while the gas content in the weak runoff zone was relatively lower.The enrichment of Gujiao mining area was controlled by structure and hydrogeological conditions.Now two hydraulic patterns were identified:The monocline-hydraulic sealing in the central of Malan was the richest area and the horst-hydraulic sealing in Dongqu was the richer area. [ABSTRACT FROM AUTHOR]

Coalbed methane high efficiency production from broken soft and low permeable coal seams has been being a technical bottleneck of restricting coalbed methane industrialization development and coal mine gas control for many years.This paper has investigated the No.8 broken soft and low permeable coal seam in Lulling coal mine of Huaibei mining area in Anhui Province,China.Site investigation,sampling and testing,theoretical analysis,hydraulic fracture physical and numerical simulation have been performed.As a result,a new model of coalbed methane high efficiency production from broken soft and low permeable coal seam by roof strata-in horizontal well and staged hydraulic fracture has been presented,the hydraulic fracture extension and control mechanism under this model have been revealed,and the main technological processes of the model implementation have been given.The results show that the roof strata are relatively brittle and have high propagation pressures,while the broken soft coal seam is relatively plastic and has a low propagation pressure.When case perforation and hydraulic fracture are performed in horizontal well of the roof strata,the hydraulic fractures in roof strata,on the vertical,extend downward and penetrate the broken soft coal seam.At the same time,the hydraulic fractures also get rapid horizontal extension,and the traction engendered by this rapid horizontal extension rips the coal seam to form long hydraulic fractures in the coal seam.Numerical simulation results show that the hydraulic fracture length formed in the broken soft and low permeable coal seam when fracturing in roof strata is long as 6.7 times as that when fracturing directly in the coal seam.Those hydraulic fractures formed in the roof strata and the broken soft coal seam are filled with sand proppant in follow-up adding-sand fracturing,and come into being a coalbed methane migration pathway from the underlying coal seam to the roof strata-in horizontal well.It can be seen that broken soft coal seam can get a good fracturing stimulation effect in this new model.The results of this study are applied to the coalbed methane development demonstration project by roof strata-in horizontal well and staged hydraulic fracture in Luling coal mine of Huaibei mining area in Anhui province,China and have obtained a good gas production effect.The average daily gas production rate of the single coalbed methane horizontal well was respectively 10 358 m3,9 039 m3,7 921 m3 in three,six and twelve consecutive months.As of November,16,2017,this horizontal well already produced 5 million cubic meters of coalbed methane gas,and its daily gas production rate was still over 3 200 m3.This has created a new record of gas production of a single coalbed methane horizontal well from broken soft and low permeable coal seam in China. [ABSTRACT FROM AUTHOR]

China is relatively rich in coalbed methane.A better estimation of maximum adsorption capacity and recovery ratio is based on a better understanding of isothermal adsorption curve.This paper is going to make a comparative study on Langmuir equation,the representative theory of monolayer adsorption theory,and DR equation,which is based on micropore filling theory on an attempt to find a more suitable model fitting equation.Data of the coal sample from four different coal ranks (Ro,max from 0.60% to 3.18%) are fitted.The result shows that VL and pL would be more accurate in physical significance and the equation fitting would be more meaningful if the two parameters are calculated before fitted;the accuracy of other parameters is improved while V0 in DR equation is calculated;and Amankwah method is the most suitable method for calculating p0 after a comparison of five calculation methods by introducing the concept of virtual saturated vapor pressure.DR equation works better in fitting effect and comes nearer to the actual data after a comparison between Langmuir and DR equation. [ABSTRACT FROM AUTHOR]

The paper carried out the adsorption/desorption experiments under different water contents,and the results show that the adsorption capacity decreases and the desorption rate increases with the increase of the water content under the balanced pressure and temperature.At the same temperature,the saturated adsorption capacity and the final desorption rate of coal show a good linear relationship with the water content,and the saturated adsorption capacity is almost not affected by water content.By fitting analysis,it is found that the Langmuir model can accurately describe the adsorption behavior of CBM,the improved Langmuir model is suitable to describe the desorption behavior and newly improved Langmuir model can be used to accurately fit the desorption rate data.With the increase of temperature,the parameter a in Langmuir model decreases.With the increase of water content and temperature,the parameter b decreases. [ABSTRACT FROM AUTHOR]

Coalbed methane (CBM) exploitation feasibility is determined by both hydrogeological conditions and hydraulic fracturing conditions of coal seams.Exploitation feasibility evaluation and reservoir evaluation constitute two important aspects of coalbed methane recoverability.In this paper,through the drainage efficiency comparison between Shouyang and Shizhuang CBM blocks in Qinshui Basin,CBM exploitation feasibility evaluation was discussed from four aspects,including coal measures aquosity,faulting,in-situ-stress state and the lithology combination of coalbed with adjacent rocks.An evaluation flow chart for CBM exploitation feasibility evaluation was finally proposed.The study shows that coal measures aquosity plays an important role in the CBM exploitation feasibility of whole CBM Block.The hydraulic communication between coal seams and surrounding aquifers through faults weakens the closeness of wellbore-fracturing coal system,leading to lower exploitation feasibility of CBM resources near the faults.The stronger the coal measures aquosity is,the greater risk of high water production in wells near faults will take place and the lower exploitation feasibility will be.The in-situ stress state of coalbed and lithology combination of coal seams with adjacent rocks constitute the objective conditions of CBM exploitation feasibility,and a comprehensive evaluation of exploitation feasibility should be done through combining in-situ stress state,the strength of horizontal stress and fracturing volumes.The qualitative/semi-quantitative evaluation method of CBM exploitation feasibility,based on hierarchy analysis considering coal measures aquosity,faults,the in-situ stress state and the lithology combination of coal seams with adjacent rocks,can be applied to CBM block selection and well/coalbeds selection through the whole process of CBM exploration and development. [ABSTRACT FROM AUTHOR]

Previous material balance equations (MBEs) were established under the assumption that the adsorption and desorption process of coalbed methane (CBM) is completely reversible and the adsorption hysteresis phenomenon observed in CBM adsorption/desorption experiment was neglected,which is obviously not consistent with the actual depressurization process of CBM reservoirs by water drainage.This paper proposed the concept of adsorption hysteresis effect based on laboratory observation and analysis of the potential mechanisms.Furthermore,an improved MBE model of CBM reservoirs considering the adsorption hysteresis effect was established,and it was applied in predicting the original gas in place (OGIP),recoverable reserves and recovery factor of some actual CBM reservoir.The results show that MBEs may significantly underestimate the OGIP while overestimating the recovery factor if the adsorption hysteresis effect is not included in the calculations.Conversely,the calculated OGIP and average water saturation are in good agreement with the actual values using the new MBE model that incorporates the adsorption hysteresis effect.Therefore,the validity and accuracy of the new MBE model is proved,and then the proposed material balance method can be potentially applied in evaluating the recoverable reserves and recovery factor of CBM reservoirs,which would also play a major guiding role in the subsequent development planning and adjustment of CBM reservoirs. [ABSTRACT FROM AUTHOR]

In order to understand the influence laws of geologic structure on the gas production of coalbed methane (CBM) well, the paper made the Changzhi Block, Qinshui basin, as an example, and introduced the variation coefficient of coal thickness to express the complexity degree of geologic structure. Then the complexity degree of geologic structure was evaluated and structure network units were divided by means of analytic hierarchy process (AHP). Furthermore, based on the results of fuzzy mathematics analysis on the factors affecting CBM productivity, including the geological condition,reservoir physical property and gas content,the relative evaluation method of AHP-fuzzy mathematics about the influence degrees of geologic structure on the production effect of CBM wells were established. The research showed that Changzhi block could be classified as simple structure area, relative simple structure area and secondary development structure area by the complexity degree of geologic structure. The evaluation scores of productivity of CBM wells from high to low are relative simple area，simple area, secondary development area in order. In other words,there is the greatest productivity of CBM wells in the relative simple area, the second in the simple, and the least in secondary development area. Meanwhile the effect of gas and water production and production curves features show that this evaluation results are in agreement with actual situation. It reflects that the evaluation method of AHP-fuzzy mathematics which is established about the influence of geological structure to CBM productivity is reasonable. Finally the evaluation results could provide references for choosing wells and improving productivity. [ABSTRACT FROM AUTHOR]

The characteristics of a CBM well performance is complex due to multiple influencing factors. It is beneficial for well site/layer selection and fracturing design to diagnose the performance of single CBM well. Based on the geological conditions and well performance data of 30 CBM wells producing from No.3 coal seam of Permian Shanxi formation in Shizhuang block，this paper studies the characteristics of CBM Wells performances and the relationship between gas production and water production. A negative enveloping relationship between gas production and water production is revealed，with high water production generally inhibiting high gas production. From a point of view of closeness of system borehole-stimulated coal interval，the mechanism of high water production due to outside water supply from sandstone aquifers is discussed and a hierarchical performance diagnostic method for single CBM well is proposed. The performance of some typical well are diagnosed using this hierarchical method，showing the method provides a tool for understanding the performance of single CBM well in Shizhuang CBM block and the application of this method can be extended to other CBM blocks. [ABSTRACT FROM AUTHOR]

Selected areas evaluation of coalbed methane has always been an important link in the process of coalbed methane (CBM) exploration，in which the evaluation method is the key to favorable area. The methods gradually developed from the qualitative evaluation to quantitative evaluation in recent years. This paper uses southern Junggar Basin as an appraisal area. Firstly，five typical kinds of evaluation methods are discussed，in which the merits and demerits are systematically expounded. It is founded that qualitative evaluations are still practical，although quantitative evaluations have improved the veracity of evaluation，subjectivism and empirical judgments are still existed in the process of quantitative evaluations to some extent. Based on the differences and similarities of the five evaluation methods，principal component analysis (PCA) has been proposed for the purpose that avoids the subjectivism and empirical judgments. The Sigonghe to Dahuangshan area has been selected as a favorable area by PCA method，the same result is generated by the five evaluation methods，which proves that the PCA method is feasible in selecting the favorable CBM areas，and its greatest advantage is to avoid the subjectivism. The authors advocate that the thought of “first qualitative judgment，second quantitative analysis，and final qualitative verification” should be used to select favorable CBM areas. [ABSTRACT FROM AUTHOR]

In terms of the exploration of coal and coalbed methane,the advantage is a high exploration degree of coal and coalbed methane (CBM) and the disadvantage is a high overlap rate of mining right for CBM exploration and development in a coal mining area.Therefore,the study of spatial-temporal relationship of exploration and development is of significance for the safe and efficient coordination development of CBM and coal in a coal mining area.Based on the comprehensive analysis of the spatial-temporal replacement characteristics of coal and the present mining right situation of coal and CBM,with coal mine or exploration area as a basic unit,Huainan-Huaibei coalfield can be divided into seven different blocks.Based on the system analysis of the exploration and development sequence of CBM and coal and the development mode of CBM,combined with CBM geological conditions,with the spatial and sequence arrangement as mainline,this paper discussed the exploration and development principle of CBM and coal,the development mode of CBM,the distribution of key blocks,the gas bearing area,and the quantity of resource,and built up the pattern of spatial-temporal collocation for CBM and coal.The study provided a technical solution for the mining right overlap,and also provided a theoretical direction for the coordinated development of CBM and coal in Huainan-Huaibei coalfield. [ABSTRACT FROM AUTHOR]

Hydraulic fracturing is a common method for increasing the production of coal-bed gas，the fracturing effect is important，and the transient electromagnetic is an effective method for its detection.In this paper，the authors discussed the theory of transient electromagnetic wave-field transformation，realized the extraction of wave-field characteristics from transient electromagnetic signal，proposed an inversion imaging method of velocity analysis based on the waveform characteristics of pseudo wave-field，calculated the inversion results of a three-dimensional numerical model data，achieved an excellent imaging effect for cracking. At last，the practicability and effective of the imaging method were proved by two actual exploration operations in underground. The conclusions show that the inversion imaging method of TEM pseudo wave-field can solve the problem of coal-bed gas hydraulic fracturing in underground. [ABSTRACT FROM AUTHOR]

The unconventional gas resource in coal measures strata is the main part of unconventional gas. At present, the understanding of coalbed methane, shale gas and tight sandstone gas in the coal measures strata is relatively limited. Also, the degrees of resources exploration and development are relatively low. According to the experiences of gas reservoir combined mining, the coal measure strata can be considered as a whole, then the cost of exploration and development on coalbed methane, shale gas and tight sandstone gas in the coal measures strata could be reduced. In addition, the efficiency and single well profit of gas well could be improved. In this paper, the coalbed methane, the shale gas and the tight sandstone gas in coal measures strata are referred to as “the three coal gases”. The commingling possibility of “the three coal gases” and the difficulties that commingling urgently needs were analyzed from the formation lithology distribution characteristics of coal measures strata lithology, accumulation mechanisms, reservoir characteristics, exploitation characteristics, etc. [ABSTRACT FROM AUTHOR]

Based on a demonstration project of coal-formed gas co-exploration and concurrent production, this paper analysed the occurrence characteristics and development conditions of Longtan coal measure coalbed methane and tight gas, and discussed the suitable technology for the coal-formed gas co-exploration and concurrent production. The results show that coal-formed gas is mainly hosted in the multiple coal seams of Longtan coal measures and closes to the gas bearing formation which contains fine sandstone and siltstone；it has enough resource and favorable development conditions that include the multi-layer commingling development and the concurrent production of coal-formed gas. The coal reservoir with the characteristics of high temperature, overpressure, high gas content and gas supersaturated is suitable to coalbed methane ground development；but some factors including the reservoir fracture closing and mineral filling could lead to the lower original permeability at high ground stress area. Therefore, the coal-formed gas ground development needs to carry out the reservoir reconstruction. The key technology of discovering, recognizing and evaluating the optimization of gas bearing and producing layers in field coal-formed gas co-exploration and concurrent production are gas logging, uncorrected comprehensive logging and the comprehensive evaluation of gas bearing layer. They provide the basis for establishing the coal-formed gas co-exploration and concurrent production scheme. In the development mode of collecting well group, the technologies including the small-layer perforating, group-segment fracturing and multi-layer drainage need to match with the topography and geology conditions of the field. Thus it can significantly improve the engineering effect of the multi-layer commingling development and the coal-formed gas co-exploration and concurrent production. [ABSTRACT FROM AUTHOR]

For further improvement of the degree of coal-bed methane (CBM) exploration and development and accelerating the development of CBM industry, the present situation and existing problems of CBM exploration and development are analyzed in detail in this paper. It is potential for prospecting and exploitation that the CBM resources of which burial depth deeper than 1 200 m are abundant and commonly with tight sandstone gas composite symbiosis in China. According to the development features of CBM and coal measures sandstone gas, there are two types of the gas reservoir models, the one, gas self-generated and self-stored in reservoir, the other, gas internally generated but externally stored in reservoir. As a result, the coal seams and sandstone intervals should be unified as target layers integrated studied, then, the CBM exploration area in vertical direction will be expanded, the resource abundance can be increased, and the reservoir stimulation effect is much better than fractured in only coal seams. Such suggests as exploring and developing these complex natural gas in deep coal measure strata for promoting the development of CBM industry are finally presented. [ABSTRACT FROM AUTHOR]

It is found that there are two difficult problems in China CBM industry. The one is that not only the success rate of drilling and fracking is very low but also gas rates from more than 50% of those producing wells are far less than they are originally designed. The other is that almost all the production activities happen in a very concentrated small area, leaving more than 80% of China CBM resources far away from commercial potentials. A new model of CBM resource classification is established after a full discussion is made on how a soluid of coal-water-gas is built in the long geology history. And technologies applicable to produce gas from the 4 types of reserves in the model is accordingly recommended. Further studies in this paper concludes that CBM resources are different from other natural gas by three aspects. Firstly it is "Non-gas"in underground. Typical CBM is presented in four kinds of Soluids, in which coal-water-gas are coupled together driven by a combination energy of "pressure" and "stress". Secondly gas has to be "Separated and Fostered" before it is drained to the surface. Actually a real independent gas flow cannot be normally delivered from seam until an effective process of "dewater" or "de-coal" is done. Thirdly there is a strong "window longtail effects" in poor CBM reservoir. No appreciable gas could be drained if there is no good engineering control over "time window" on reservoir stimulation, neither is there any sustainable gas flow if "pumping longtail" is not well managed. [ABSTRACT FROM AUTHOR]

According to the results of China’s new round of CBM resource evaluation in 2006, coalbed methane (CBM) resources were mainly concentrated in the deep seams (coal seam depth in 1 000-2 000 m), but studies related to deep CBM theory were limited, and exploration operations were rare. In this paper, based on the main distribution of coalbed methane resources in the deep coal seams in China, the current deep coal seam mining and CBM exploration wells in Erdos basin and Junggar basin indicate that the exploration and development of deep CBM shows some potential, although the appraisal wells of commercial value occur only in a few pilot areas. By comparing different coal seam depth studies in Yanchuannan block in Erdos basin, it could be concluded that the key parameters such as the gas content, gas saturation,reservoir pressure and critical desorption pressure of deep coal seams were commonly higher than in shallow coal seams. In general, it was a complex system engineering to evaluate the factors of deep CBM production, which generally include resource geology and development technology. Geological conditions of deep CBM were more complicated than those of shallow CBM, which resulted in that the development technology applied in these area was difficult. According to the experience of exploration and production in Yanchuannan pilot CBM project, it was fracturing technique adapted for deep geological condition and draining technology that responsible for favorable well production. Based on this study, it is proposed that the improved well production way of deep CBM is to do the evaluation and prediction of sweet point, to study the fracturing technology and to manage drainage working system. [ABSTRACT FROM AUTHOR]