As a result of advances in horizontal comple- tions and multi-stage hydraulic fracturing, the U.S. has been able to economically develop several decades of worth of natural gas. However, a considerable concern has ris...As a result of advances in horizontal comple- tions and multi-stage hydraulic fracturing, the U.S. has been able to economically develop several decades of worth of natural gas. However, a considerable concern has risen on the economic viability of shale gas development for reasons associated with the fast production declines as well as recent down-turns of natural gas prices besides rises in the costs of new technologies. Therefore, an economic analysis is required to investigate the profitability of the re- fracturing treatment of unconventional gas resources. Net present value of cash flows and internal rate of return are calculated for a range of gas prices considering 20 years of natural gas production from a typical unconventional shale gas reservoir. A systematic comparison is then accom- plished for three scenarios: (1) re-fracturing versus no re- fracturing, (2) combination of re-fracturing and drilling new wells, and (3) time-dependent re-fracturing treatment. Further, this paper incorporates the cost of re-fracturing treatment, the cost of drilling a new horizontal well, the water treatment cost, as well as the current and future price of natural gas in the model. The findings of this work would help the future re-stimulation development plans of the emerging unconventional shale gas plays.展开更多
The effect of the supermoleclar structure of polyester on the effective alkali hy-drolysisis rate constant k has been investigated in the paper.That the average non-crvstal line volume around per crystal grain has a c...The effect of the supermoleclar structure of polyester on the effective alkali hy-drolysisis rate constant k has been investigated in the paper.That the average non-crvstal line volume around per crystal grain has a close relation to the k is proved byexperiments.A simple and effctive method for assessing what effect of the super-molecular structure on the k by its CDT value( Critical Dissolution Time) has beenput forward.展开更多
文摘As a result of advances in horizontal comple- tions and multi-stage hydraulic fracturing, the U.S. has been able to economically develop several decades of worth of natural gas. However, a considerable concern has risen on the economic viability of shale gas development for reasons associated with the fast production declines as well as recent down-turns of natural gas prices besides rises in the costs of new technologies. Therefore, an economic analysis is required to investigate the profitability of the re- fracturing treatment of unconventional gas resources. Net present value of cash flows and internal rate of return are calculated for a range of gas prices considering 20 years of natural gas production from a typical unconventional shale gas reservoir. A systematic comparison is then accom- plished for three scenarios: (1) re-fracturing versus no re- fracturing, (2) combination of re-fracturing and drilling new wells, and (3) time-dependent re-fracturing treatment. Further, this paper incorporates the cost of re-fracturing treatment, the cost of drilling a new horizontal well, the water treatment cost, as well as the current and future price of natural gas in the model. The findings of this work would help the future re-stimulation development plans of the emerging unconventional shale gas plays.
文摘The effect of the supermoleclar structure of polyester on the effective alkali hy-drolysisis rate constant k has been investigated in the paper.That the average non-crvstal line volume around per crystal grain has a close relation to the k is proved byexperiments.A simple and effctive method for assessing what effect of the super-molecular structure on the k by its CDT value( Critical Dissolution Time) has beenput forward.