Based on regional CBM geological characteristics and drainage data of three typical Coalbed Methane(CBM) wells in the southern Qinshui Basin,history matching,productivity prediction and factor analysis of gas producti...Based on regional CBM geological characteristics and drainage data of three typical Coalbed Methane(CBM) wells in the southern Qinshui Basin,history matching,productivity prediction and factor analysis of gas production control are conducted by using COMET3 reservoir modeling software.The results show that in the next 20 years,the cumulative and average daily gas production of the QN01 well are expected to be 800×104 m3 and 1141.1 m3/d,for the QN02 well 878×104 m3 and 1202.7 m3/d and 97.5×104 m3 and 133.55 m3/d for the QN03 well.Gas content and reservoir pressure are the key factors controlling gas production in the area;coal thickness,permeability and porosity are less important;the Langmuir volume,Langmuir pressure and adsorption time have relatively small effect.In the process of CBM recovery,the material source and driving force are the key features affecting gas productivity,while the permeation process is relatively important and the desorption process has some impact on gas recovery.展开更多
Based on controls of structural style and the position in coalbed methane (CBM) development, we used a method of curvatures to study its relations with CBM development parameters. We calculated structural curvatures o...Based on controls of structural style and the position in coalbed methane (CBM) development, we used a method of curvatures to study its relations with CBM development parameters. We calculated structural curvatures of contours of the No.3 coal seam floor of the Shanxi Formation in the Zaoyuan block of the Qinshui Basin and analyzed its relations with development parameters of coalbed methane wells. The results show that structural curvature is negatively related to coal reservoir pressure, while positively related to permeability. With an increase in structural curvature, the average production of coalbed methane wells increases at first and then decreases, reaching the highest production at 0.02 m–1 of structural curvature. Therefore, structural cur-vature can be an important index for potential evaluation of coalbed methane development and provide a basis for siting coalbed methane wells.展开更多
Based on spontaneous desorption characteristic, the correlation of desorption time and gas content was analyzed and the application of it in production was researched. The desorption of high rank coalbed methane in Qi...Based on spontaneous desorption characteristic, the correlation of desorption time and gas content was analyzed and the application of it in production was researched. The desorption of high rank coalbed methane in Qinshui basin was periodic, and isotope fractionation effect also exists in the process. △δ^13C1 can be used to distinguish the stabilization of coalbed methane wells, associated with desorption rate, the individual well recoverable reserves can be calculated. Economically recoverable time can be predicted according to the logarithmic relationship between desorption gas content per ton and desorption time. The error between predicted result and numerical simulation result is only 1.5%.展开更多
Effective migration system of coalbed methane(CBM)reservoir,which was controlled by development degree and opening-closing degree of fractures,determines the permeability of coal reservoir and can be characterized by ...Effective migration system of coalbed methane(CBM)reservoir,which was controlled by development degree and opening-closing degree of fractures,determines the permeability of coal reservoir and can be characterized by the pore-fracture system in the extrinsic form.In this paper,based on coal matrix elastic self-regulating effect theory and coal reservoir combined elastic energy theory,the fracture opening-closing degree parameterΔand the fracture development degree parameterξare suggested for the quantitative study of the effective migration system of CBM reservoir in southern Qinshui Basin.Further,the control functions ofξandΔto CBM enrichment and high production are discussed.The results show that in present stage the area with highξvalue is located in Anze and Qinyuan,and then Zhengzhuang and Fangzhuang,where fracture development degree is high.The area with highΔvalue is located in Zhengzhuang and Fanzhuang,and then Anze and Qinyuan,indicating where coal matrix elastic self-regulating positive effect dominates and fractures tend to be open.Through the comprehensive analysis onξandΔ,it can be found that their best match area is located in Zhengzhuang and Fanzhuang,with high values for fracture development degree and opening-closing degree probably bringing about high fluid pressure and good permeability of reservoirs,which are advantageous to an abundant CBM production.展开更多
基金the National Basic Research Program of China (No.2009 CB219605)the Key Program of the National Natural Science Foundation of China (No.4073042)the Key Program of the National Science and Technology of China (No.2008ZX05034-04)
文摘Based on regional CBM geological characteristics and drainage data of three typical Coalbed Methane(CBM) wells in the southern Qinshui Basin,history matching,productivity prediction and factor analysis of gas production control are conducted by using COMET3 reservoir modeling software.The results show that in the next 20 years,the cumulative and average daily gas production of the QN01 well are expected to be 800×104 m3 and 1141.1 m3/d,for the QN02 well 878×104 m3 and 1202.7 m3/d and 97.5×104 m3 and 133.55 m3/d for the QN03 well.Gas content and reservoir pressure are the key factors controlling gas production in the area;coal thickness,permeability and porosity are less important;the Langmuir volume,Langmuir pressure and adsorption time have relatively small effect.In the process of CBM recovery,the material source and driving force are the key features affecting gas productivity,while the permeation process is relatively important and the desorption process has some impact on gas recovery.
基金support for this work, provided by the National Basic Research Program of China (No2009 CB219605)the National Major Research Program for Science and Technology of China (No2008 ZX05033-003)
文摘Based on controls of structural style and the position in coalbed methane (CBM) development, we used a method of curvatures to study its relations with CBM development parameters. We calculated structural curvatures of contours of the No.3 coal seam floor of the Shanxi Formation in the Zaoyuan block of the Qinshui Basin and analyzed its relations with development parameters of coalbed methane wells. The results show that structural curvature is negatively related to coal reservoir pressure, while positively related to permeability. With an increase in structural curvature, the average production of coalbed methane wells increases at first and then decreases, reaching the highest production at 0.02 m–1 of structural curvature. Therefore, structural cur-vature can be an important index for potential evaluation of coalbed methane development and provide a basis for siting coalbed methane wells.
文摘Based on spontaneous desorption characteristic, the correlation of desorption time and gas content was analyzed and the application of it in production was researched. The desorption of high rank coalbed methane in Qinshui basin was periodic, and isotope fractionation effect also exists in the process. △δ^13C1 can be used to distinguish the stabilization of coalbed methane wells, associated with desorption rate, the individual well recoverable reserves can be calculated. Economically recoverable time can be predicted according to the logarithmic relationship between desorption gas content per ton and desorption time. The error between predicted result and numerical simulation result is only 1.5%.
基金jointly supported by National Natural Science Foundation of China(Grant No.41272178)the Major Projects of National Science and Technology of China(Grant No.2011ZX05034)+1 种基金National Basic Research Program of China(Grant No.2009CB219605)"Qinglan"Project of Jiangsu Province
文摘Effective migration system of coalbed methane(CBM)reservoir,which was controlled by development degree and opening-closing degree of fractures,determines the permeability of coal reservoir and can be characterized by the pore-fracture system in the extrinsic form.In this paper,based on coal matrix elastic self-regulating effect theory and coal reservoir combined elastic energy theory,the fracture opening-closing degree parameterΔand the fracture development degree parameterξare suggested for the quantitative study of the effective migration system of CBM reservoir in southern Qinshui Basin.Further,the control functions ofξandΔto CBM enrichment and high production are discussed.The results show that in present stage the area with highξvalue is located in Anze and Qinyuan,and then Zhengzhuang and Fangzhuang,where fracture development degree is high.The area with highΔvalue is located in Zhengzhuang and Fanzhuang,and then Anze and Qinyuan,indicating where coal matrix elastic self-regulating positive effect dominates and fractures tend to be open.Through the comprehensive analysis onξandΔ,it can be found that their best match area is located in Zhengzhuang and Fanzhuang,with high values for fracture development degree and opening-closing degree probably bringing about high fluid pressure and good permeability of reservoirs,which are advantageous to an abundant CBM production.
