致密含水气藏具有低压、低孔、低渗、非均质性强、含气饱和度低以及孔喉细小等储层特征。为了研究提高配产对致密含水气藏气井开发效果的影响,对比分析了提高配产前后不同提高配产比例和不同液气比气井的压力、单井最终可采储量(EUR)及...致密含水气藏具有低压、低孔、低渗、非均质性强、含气饱和度低以及孔喉细小等储层特征。为了研究提高配产对致密含水气藏气井开发效果的影响,对比分析了提高配产前后不同提高配产比例和不同液气比气井的压力、单井最终可采储量(EUR)及阶段累产气等开发参数。研究结果表明:1)提高配产比例及气井液气比越大,气井EUR下降幅度也越大;当气井提高配产比例大于50%或液气比大于5 m^(3)/(×10^(4) m ^(3))时,EUR下降比例可达40%。2)致密含水储层应力敏感程度增幅7%~12%,且含水饱和度越高,应力敏感程度越强,渗透率急剧降低。3)生产压差增大,参与流动的地层水增多,近井地带更易积液且积液范围将扩展至地层中部,造成采收率大幅下降。4)井筒内液滴回落,流体侵入储层容易引起近井地带水锁,造成气相渗流能力大幅下降。该研究成果对同类型含水气藏科学合理开发有指导意义。展开更多
In order to assure the safety and efficacy of the Chinese Medicines in Europe, the quality of TCM herbals should be guaranteed so that they can be freely imported in the European Union and other Western European Count...In order to assure the safety and efficacy of the Chinese Medicines in Europe, the quality of TCM herbals should be guaranteed so that they can be freely imported in the European Union and other Western European Countries which are signatories of the European Pharmacopoeia Convention. Consequently, new Ph Eur TCM herbal drug Monographs should be elaborated, based on preexisting Monographs in the Chinese Pharmacopoeia(Ch P) 2010.Such a program has been inaugurated in 2005 by the Ph Eur Groups of Experts 13 A and B(Phytochemistry). Since then good progress has been made, elaborating of about one third of the originally proposed 100 TCM herbals being identified as important monographs for the European Market. Taking into account the many challenges still laying ahead, the establishment of a specialized Working Party(WP) on TCM with specialists and experts from many EU Member States has been decided by the Ph Eur Commission in 2008 which is highly active ever since in the examination and elaboration of new TCM herbal drug monographs, primarily to assure the safety of the European patient and further to provide quality parameters extremely important for all registration and licensing procedures of the respective National Authorities all over Europe.This paper is a survey of results and difficulties obtained so far which has been encountered meanwhile in the elaboration process by the Ph Eur TCM WP of these monographs and will discuss these in detail. Moreover the role of Ph Eur TCM monographs in the European community is addressed.展开更多
Development of unconventional shale gas resources involves intensive capital investment accompa- nying large commercial production uncertainties. Eco- nomic appraisal, bringing together multidisciplinary project data ...Development of unconventional shale gas resources involves intensive capital investment accompa- nying large commercial production uncertainties. Eco- nomic appraisal, bringing together multidisciplinary project data and information and providing likely economic outcomes for various development scenarios, forms the core of business decision-making. This paper uses a dis- counted cash flow （DCF） model to evaluate the economic outcome of shale gas development in the Horn River Basin, northeastern British Columbia, Canada. Through numerical examples, this study demonstrates that the use of a single average decline curve for the whole shale gas play is the equivalent of the results from a random drilling process. Business decision based on a DCF model using a single decline curve could be vulnerable to drastic changes of shale gas productivity across the play region. A random drilling model takes those drastic changes in well estimated ultimate recovery （EUR） and decline rates into account in the economic appraisal, providing more information useful for business decisions. Assuming a natural gas well-head price of S4/MCF and using a 10 % discount rate, the results from this study suggest that a random drilling strategy （e.g., one that does not regard well EURs）, could lead to a negative net present value （NPV）; whereas a drilling sequence that gives priority to developing those wells with larger EURs earlier in the drilling history could result in a positive NPV with various payback time and internal rate of return （IRR）. Under a random drilling assumption, the breakeven price is S4.2/MCF with more than 10 years of payout time. In contrast, if the drilling order is strictly proportional to well EURs, the result is a much better economic outcome with a breakeven price below the assumed well-head price accompanied by a higher IRR.展开更多
文摘致密含水气藏具有低压、低孔、低渗、非均质性强、含气饱和度低以及孔喉细小等储层特征。为了研究提高配产对致密含水气藏气井开发效果的影响,对比分析了提高配产前后不同提高配产比例和不同液气比气井的压力、单井最终可采储量(EUR)及阶段累产气等开发参数。研究结果表明:1)提高配产比例及气井液气比越大,气井EUR下降幅度也越大;当气井提高配产比例大于50%或液气比大于5 m^(3)/(×10^(4) m ^(3))时,EUR下降比例可达40%。2)致密含水储层应力敏感程度增幅7%~12%,且含水饱和度越高,应力敏感程度越强,渗透率急剧降低。3)生产压差增大,参与流动的地层水增多,近井地带更易积液且积液范围将扩展至地层中部,造成采收率大幅下降。4)井筒内液滴回落,流体侵入储层容易引起近井地带水锁,造成气相渗流能力大幅下降。该研究成果对同类型含水气藏科学合理开发有指导意义。
文摘In order to assure the safety and efficacy of the Chinese Medicines in Europe, the quality of TCM herbals should be guaranteed so that they can be freely imported in the European Union and other Western European Countries which are signatories of the European Pharmacopoeia Convention. Consequently, new Ph Eur TCM herbal drug Monographs should be elaborated, based on preexisting Monographs in the Chinese Pharmacopoeia(Ch P) 2010.Such a program has been inaugurated in 2005 by the Ph Eur Groups of Experts 13 A and B(Phytochemistry). Since then good progress has been made, elaborating of about one third of the originally proposed 100 TCM herbals being identified as important monographs for the European Market. Taking into account the many challenges still laying ahead, the establishment of a specialized Working Party(WP) on TCM with specialists and experts from many EU Member States has been decided by the Ph Eur Commission in 2008 which is highly active ever since in the examination and elaboration of new TCM herbal drug monographs, primarily to assure the safety of the European patient and further to provide quality parameters extremely important for all registration and licensing procedures of the respective National Authorities all over Europe.This paper is a survey of results and difficulties obtained so far which has been encountered meanwhile in the elaboration process by the Ph Eur TCM WP of these monographs and will discuss these in detail. Moreover the role of Ph Eur TCM monographs in the European community is addressed.
基金funded partly by the eco EII program and supported by Geoscience for New Energy Supply Program of Natural Resources Canada
文摘Development of unconventional shale gas resources involves intensive capital investment accompa- nying large commercial production uncertainties. Eco- nomic appraisal, bringing together multidisciplinary project data and information and providing likely economic outcomes for various development scenarios, forms the core of business decision-making. This paper uses a dis- counted cash flow （DCF） model to evaluate the economic outcome of shale gas development in the Horn River Basin, northeastern British Columbia, Canada. Through numerical examples, this study demonstrates that the use of a single average decline curve for the whole shale gas play is the equivalent of the results from a random drilling process. Business decision based on a DCF model using a single decline curve could be vulnerable to drastic changes of shale gas productivity across the play region. A random drilling model takes those drastic changes in well estimated ultimate recovery （EUR） and decline rates into account in the economic appraisal, providing more information useful for business decisions. Assuming a natural gas well-head price of S4/MCF and using a 10 % discount rate, the results from this study suggest that a random drilling strategy （e.g., one that does not regard well EURs）, could lead to a negative net present value （NPV）; whereas a drilling sequence that gives priority to developing those wells with larger EURs earlier in the drilling history could result in a positive NPV with various payback time and internal rate of return （IRR）. Under a random drilling assumption, the breakeven price is S4.2/MCF with more than 10 years of payout time. In contrast, if the drilling order is strictly proportional to well EURs, the result is a much better economic outcome with a breakeven price below the assumed well-head price accompanied by a higher IRR.
