Browsing by Author "Shen, Yinghao (TTU)"
Now showing 1 - 4 of 4
- Results Per Page
- Sort Options
Item Impact of Petrophysical Properties on Hydraulic Fracturing and Development in Tight Volcanic Gas Reservoirs(2017) Shen, Yinghao (TTU); Meng, Mianmo; Liu, Tao; Ge, Hongkui; Zhang, YueleiThe volcanic reservoir is an important kind of unconventional reservoir. The aqueous phase trapping (APT) appears because of fracturing fluids filtration. However, APT can be autoremoved for some wells after certain shut-in time. But there is significant distinction for different reservoirs. Experiments were performed to study the petrophysical properties of a volcanic reservoir and the spontaneous imbibition is monitored by nuclear magnetic resonance (NMR) and pulse-decay permeability. Results showed that natural cracks appear in the samples as well as high irreducible water saturation. There is a quick decrease of rock permeability once the rock contacts water. The pores filled during spontaneous imbibition are mainly the nanopores from NMR spectra. Full understanding of the mineralogical effect and sample heterogeneity benefits the selection of segments to fracturing. The fast flow-back scheme is applicable in this reservoir to minimize the damage. Because lots of water imbibed into the nanopores, the main flow channels become larger, which are beneficial to the permeability recovery after flow-back of hydraulic fracturing. This is helpful in understanding the APT autoremoval after certain shut-in time. Also, Keeping the appropriate production differential pressure is very important in achieving the long term efficient development of volcanic gas reservoirs.Item Ion Diffusion Behavior between Fracturing Water and Shale and Its Potential Influence on Production(2017) Shen, Yinghao (TTU); Zhu, Zhaopeng; Shi, Peng; Ge, Hongkui; Yang, ZhihuiWater imbibition, conductivity measurements, and ion identification were performed to investigate ion diffusion behavior between slick water and shale for large-scale hydraulic fracturing. The results indicated that there was strong ion exchange between water and shale. The ion concentration in water increases with fracture complexity and is dependent on the salinity of fracturing fluids. This implies that fracturing effects could be forecast from flow-back fluid ion concentrations after large-scale slick water fracturing. Higher levels of ion diffusion imply the presence of larger fracturing areas and higher level of fracture density for a similar reservoir. The mechanism of ion diffusion and the corresponding effects on IOR (increased oil recovery) based on a field example are discussed.Item Optimization of coiled-tubing drainage gas recovery technology in tight gas field(2017) Shen, Yinghao (TTU); Luan, Guohua; Ge, Hongkui; Yang, Xinyu; Liu, Qian; Guo, XuejingIn this study, research progress on critical liquid-carrying theory was introduced and its applicable conditions were presented and analyzed. The design technique of coiled-tubing drainage gas recovery was proposed, including the design method and calculation formula of diameter of coiled tubing, strength, and installation of a gas well Christmas tree, along with running time. Based on the design method, coiled-tubing drainage gas recovery technology was used in SD block of Sulige gas field to solve the problem of gas effusion. The field test results show a good effect of smaller pressure difference and higher gas production rate when the coiled-tubing drainage gas recovery method is used.Item Review on gas flow and recovery in unconventional porous rocks(2017) Lin, Duanlin; Wang, Jinjie; Yuan, Bin; Shen, Yinghao (TTU)This study summarizes gas flow process in unconventional porous rocks, including the transportation in tight or shale reservoirs and the spontaneous imbibition happened in them. Fluids flow is greatly affected by the pore structure together with the pore size distribution of porous media. The MRI and BET measurement show peaks in pore throat radius ranging from 2 to 20 nm, whereas the diameter for methane and helium are 0.38 and 0.26 nm, respectively. Yet for different types of reservoir, distinct mechanisms should be utilized based on the flow regimes. Besides, experimental measurement techniques for conventional reservoirs are no long accurate enough for most of the unconventional reservoirs. New attempts have been implemented to obtain more valuable data for accurate reservoir prediction. By reviewing large numbers of articles, a clear and comprehensive map on the gas flow and recovery in unconventional reservoirs is made. Factors influencing the gas flow and recovery are investigated in detail for mathematical simulation process. Reservoir conditions and the sweep efficiency play an important role during gas production process. Besides, adsorbed gas contributes a lot to the total gas recovery. The overall investigations suggest that many parameters that influence the gas flow in unconventional porous rocks should be taken into consideration during the evaluation. Among them, permeability, adsorbed gas dynamics, stimulated reservoir volume as well as the unstimulated reservoir volume, and imbibition effect are the most important ones. This study provides valuable data and reasonable exploitations for characterizing gas flow and recovery in unconventional porous rocks.