Li K.,China University of Geosciences |
Li K.,Stanford University |
Gao Y.,Petroleum Exploration and Production Research Institute |
Lyu Y.,Sinopec |
Wang M.,China Pingmei Shenma Group
SPE Journal | Year: 2015
Proppant embedment plays a significant role in decreasing fracture aperture and conductivity, especially for weakly consolidated sandstones, shale (oil and gas) rock, and coalbeds. Empirical and semiempirical models were usually used to calculate the embedment of proppants. However, the accuracy of matching or predicting the proppant embedment with these existing models may not be satisfactory in some cases. On the other hand, it is difficult to determine the coefficients of these models. In this study, analytical models were derived to compute proppant embedment and fracture conductivity. One can use these new models to calculate the proppant embedment, proppant deformation, the change in fracture aperture, and fracture conductivity in the ideal or experimental situations of either single-layer or multilayer patterns in the fractures under closure pressures. The new models showed that the proppant embedment and fracture conductivity are affected by the factors, for example, of closure pressure, fracture aperture, the elastic modulus of proppant and coalbed, the size of proppant, and the concentration of proppant-paving. Experimental data of proppant embedment in fractures and fracture conductivity of different proppants at different closure pressures were used to test the models derived in this study. The results from matching the experimental data with the new and the existing models were compared. The results showed that the new models, especially the revised new models, could match the experimental data in all the cases studied. The new models for calculating the proppant embedment and fracture conductivity with a better accuracy are of great significance in selecting proppants, which is helpful to achieve high fracture conductivity and then high oil or gas production of conventional and (especially) unconventional resources such as shale oil, shale gas, and coalbed methane. Copyright © 2015 Society of Petroleum Engineers.
Gao Y.,Sinopec |
Lv Y.,China Pingmei Shenma Group |
Wang M.,China Pingmei Shenma Group |
Li K.,China University of Geosciences |
Li K.,Yangtze University
Society of Petroleum Engineers - International Petroleum Technology Conference 2013, IPTC 2013: Challenging Technology and Economic Limits to Meet the Global Energy Demand | Year: 2013
Proppant embedment plays a significant role in decreasing fracture aperture and conductivity, especially for weakly consolidated sandstones, shale (oil and gas) rock, and coal beds. Empirical and semi-empirical models were usually used to calculate the embedment of proppants. However the accuracy of matching or predicting the proppant embedment using these existing models may not be satisfactory in some cases. On the other hand, it is difficult to determine the coefficients of these models. In this study, analytical models were derived to compute the proppant embedment and fracture conductivity. These new models can be used to calculate the proppant embedment, proppant deformation, the change in fracture aperture and fracture conductivity in the ideal or experimental situations of either single-layer or multi-layer patterns in the fractures under closure pressures. The new models showed that the proppant embedment and fracture conductivity are affected by the factors of closure pressure, fracture aperture, the elastic modulus of proppant and coal bed, the size of proppant, the concentration of proppant-paving, etc. Experimental data of proppant embedment in fractures and fracture conductivity of different proppants at different closure pressures were used to test the models derived in this study. The results from matching the experimental data using the new and the existing models were compared. The results showed that the new models especially the revised new models could match the experimental data in all of the cases studied. The new models for calculating the proppant embedment and fracture conductivity with a better accuracy are of great significance in selecting proppants, which is helpful to achieve high fracture conductivity and then high oil or gas productions of conventional, especially unconventional resources such as shale oil, shale gas, and coal bed methane. Copyright 2013, International Petroleum Technology Conference.
Li T.,University of Science and Technology Beijing |
Wang W.,University of Science and Technology Beijing |
He Z.-L.,China Pingmei Shenma Group |
Kou J.-X.,China Pingmei Shenma Group |
And 3 more authors.
Meitan Xuebao/Journal of the China Coal Society | Year: 2014
To explore the mechanism of unusual quake behavior in dip roadway during mining long distance coal seam group, on the basis of high-precision micro-seismic monitoring data and field investigation, the anthors analyzed the reasons of mining-induced quake by MapRAS which was used to analysis and forecast the laws of rockmass breaking, and the dynamic response laws of roadway surrounding rock was analyzed by distinct element method UDEC. The following conclusions were gotten. Frequent mine earthquakes in industrial square protective coal pillar and non-mining area of F-2 dip roadway are the results that key roof stratum movements act on strong shear stress zones of edge coal pillar during working face mining and the effects are directly proportional to the mining depth and inversely proportional to mining influence distance. The quake behavior often occurred in F-2 dip roadway which is non-mining direct influent area and the unusual phenomena are related to the physical and mechanical properties of F group coal, composite pressure arch springing dynamic loading and unloading effects during mining the three groups of working face and the effect distance of mine earthquake dynamic source. The authors proposed the surrounding rock of roadway quake behavior hazard level criterion and index according to the quake magnitude, quake behavior level and rock mass particle vibration velocity from numerical experimentation and the criterion basically conforms to the facts. The authors got images by inversion using micro-quake frequency and Fourier cycle method which sensitively reflect the periodic breakage laws of roof key stratum and the correlation of rock dynamic response in adjacent sections. Simulation test by UDEC reveals the effect laws of working face mining on the surrounding rock of F-2 dip roadway.
Hu J.,Henan University of Urban Construction |
Liao C.,Henan University of Urban Construction |
Chen S.,Henan University of Urban Construction |
Jin P.,China Pingmei Shenma Group |
And 2 more authors.
Inorganic Chemistry Communications | Year: 2014
To pursuit the subtle influence exerted on the structure by the anions, two new complexes, namely [Ag(pbmb)·SO3CF3] n 1, and [Ag(pbmb)·ClO4]n 2 have been constructed by the reaction of a V-shaped flexible ligand 1-((2-(pyridin-2-yl)- 1H-benzoimidazol-1-yl)methyl)-1H-benzotriazole (pbmb) and corresponding silver salts under solvothermal conditions. Single crystal analysis shows that the binuclear-based 1 and 2 are 1D motifs with different structural features, especially for complex 1 with the shortest Ag***Ag distance of 2.928 Å. Both complex 1 and 2 exhibit rich luminescent behaviors at temperatures 10-298 K, whereas complex 1 manifests stronger phosphorescence by comparison with 2. © 2014 Elsevier B.V.
Lin Y.,Henan Polytechnic University |
Wu Y.,Henan Polytechnic University |
Pan G.,Henan Polytechnic University |
Qin Y.,Henan Polytechnic University |
Chen G.,China Pingmei Shenma Group
Arabian Journal of Geosciences | Year: 2015
In North China coal basin, there is an accident: the water which comes from Ordovician system aquifer (O2) discharges into underground coal mines. The coal mining operations would be seriously threatened by this kind of accident. In order to solve this problem, the characteristics of various exploration methods have been discussed. A comprehensive approach involving hydrogeological analysis, geophysical prospecting, hydrogeological drilling, and hydrogeological field test was proposed to explore the groundwater recharge channel. A typical North China coal mine, Siwan coal mine, was taken as an example. The groundwater recharge channel on F8 fault was precisely explored and plugged. After the curtain grouting, the water discharge rate per unit of drawdown was dropped from 12.0 to 7.0 m3/(h m), and the water yield in coal mine was reduced by 600 m3/h. A much safer condition can be provided for Siwan coal mine, avoiding the waste of water resource. © 2015, Saudi Society for Geosciences.
Lu T.,Henan Polytechnic University |
Zhao Z.,China Pingmei Shenma Group |
Hu H.,Gueizhou Xiang Nan Group
International Journal of Rock Mechanics and Mining Sciences | Year: 2011
Most of the coal seams currently mined in the Southwest part of China have high gas content, are soft and prone to outbursts, which significantly influences the rate of gate road development and mining safety. It is believed that an outburst is mainly due to the internal energy stored in the coal seam, so it is necessary to release the energy to prevent the occurrences of coal and gas outbursts, which in turn improves the rate of gate road development. This paper presented herein discusses the usage of the waterjet slotting technique to prevent the occurrence of outbursts during gate road development, on the basis of the laboratory tests, numerical modeling and field work. The numerical modeling indicated that the internal effective stress levels can be reduced up to 70% and 45% for the vertical and horizontal stresses, respectively, when waterjet slotting is applied, and the field monitoring results showed that the gas concentration released from the face of excavation can be increased up to five times compared with the traditional borehole drainage method. As a result, the values Smix and K1, which are determined by drill cuttings to describe the possibility of outburst occurrences, have been kept below the critical limits 70% of the excavation time and the rate of gate road development increases from 30m to 70m per month. © 2011 Elsevier Ltd.
Guo D.,China University of Mining and Technology |
Li C.,China University of Mining and Technology |
Zhang Y.,China University of Mining and Technology |
Zhang Y.,China Pingmei Shenma Group
Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences | Year: 2014
Taking the simulation of indigenous coal and tectonically deformed coal in Pingdingshan coal district as the research object, porosity and permeability of different coal samples under different factors are determined in this paper. The variation trend of porosity and permeability under different factors is analyzed. The experimental results show that four factors analyzed have significant impact on both porosity and permeability of coal. The effect of confining pressure is greater than temperature when confining pressure and temperature work together. And part of experiment data are fitted by the Origin software, concluding with the function relationship of porosity and permeability of coal. ©, 2014, China University of Geosciences. All right reserved.
Li H.T.,North China Institute of Science and Technology |
Zhang L.,North China Institute of Science and Technology |
Weng Y.F.,North China Institute of Science and Technology |
Li H.T.,Hebei Province Key Laboratory of Mine Disaster Prevention |
Yang J.G.,China Pingmei Shenma Group
Progress in Mine Safety Science and Engineering II - Proceedings of the 2nd International Symposium of Mine Safety Science and Engineering | Year: 2014
In the context of resource integration in old coal mining area in China, taking China Pingmei-Shenma group as research object, by investigating and summarizing its' practical experience in the course of constructing safe and high-efficient mining in old mining area and resource integration mines, connotation and features are preliminarily expounded on safe and high-efficient mining model in old mining area and resource integration mines. Elements are analyzed on safe and high-efficient mining model, and theoretical framework which is based on three dimension (i.e. aim dimension, path dimension and type dimension) and elements is founded to analyze safe and high-efficient mining. Based on theoretical framework, general model and three special models (i.e. production-distribution optimized model, resources optimization deployed model and safety production improved model) are induced on safety and high efficiency mining by analyzing main points in constructing safe and high-efficient mining in old mine area and resource integration mines. © 2014 Taylor & Francis Group.
Zhang F.,Zhengzhou University |
Wei H.,Zhengzhou University |
Dou X.,China Pingmei Shenma Group |
Wang X.,Zhengzhou University
Petroleum Processing and Petrochemicals | Year: 2015
Silicalite-1 was synthesized by hydrothermal method. The catalytic performance of Silicalite-1 treated by different calcination temperatures in vapor phase Beckmann rearrangement of cyclohexanone oxime was investigated. Silicalite-1 catalysts were characterized by XRD, IR, BET and thermal analysis. The results show that the calcination temperature has an important effect on the conversion of cyclohexanone oxime and the stability of the Silicalite-1 catalyst, but no obvious influence on the selectivity of caprolactam. With the increase of calcination temperature, BET surface area of molecular sieve does not change significantly, while external surface area first increases and then decreases. The ratio of micropore volume to the total volume is on the decline. The Silicalite-1 calcinated at 400 °C exhibits an excellent activity and stability in vapor phase Beckmann rearrangement reaction.
Sha B.,Henan Academy of science |
Wang J.,Henan Academy of science |
Zhou L.,China Pingmei Shenma Group |
Zhang X.,Henan Academy of science |
And 3 more authors.
Journal of Applied Polymer Science | Year: 2013
In this study, hexamethylenediamine (HMD) and hexamethyleneimine (HMI) were removed from a real wastewater by carboxyl group-modified polyacrylonitrile (RPFC-I) fibers. Adsorption of organic amines by fibrous absorbents is a new technique. Adsorption by fibers has advantages of fast kinetic, high adsorption capacity, and efficiency. Moreover, the fibers could be repeatedly used after regeneration. Batch adsorption tests were conducted to investigate adsorption comparison of the three fibers, adsorption kinetic, adsorption isotherms, regeneration, and readsorption stability. The experiments showed that RPFC-I fibers had excellent adsorption capacity for HMI and HMD. The adsorption equilibrium was achieved very fast within about 5 min, and the removal rate of total nitrogen (TN) was above 99%. The adsorption kinetic could be well fitted by the pseudo-second-order equation. And the adsorption isotherm could be well fitted by the Langmuir model. The estimated maximum adsorption capacity was 105.2 mg g-1, nearly similar with cation exchange capacity (CEC) of RPFC-I fibers. Results from adsorption stability tests demonstrated that the RPFC-I fibers could be fully regenerated by HCl and the regenerated fibers could be repeatedly used even after 12 adsorption-desorption cycles. Analyses from Fourier transform infrared and the adsorption tests suggested that chemical reaction between carboxyl groups and organic amines was the main mechanism for removal of HMI and HMD from the wastewater. The RPFC-I fibers prepared in the current study have a wide application in wastewater treatment and useful substance recovery. © 2012 Wiley Periodicals, Inc.