Improvement of the fluidity and setting time of grouting materials has been recognized as an effective approach of seepage prevention in foundation works, and it is quite common to be used for handling severe leakages...Improvement of the fluidity and setting time of grouting materials has been recognized as an effective approach of seepage prevention in foundation works, and it is quite common to be used for handling severe leakages in complex ground conditions, such as loose, broken and fully fissured stratum. For the purposed of better meeting the engineering requirements, experimental studies were conducted in this study with focus on the nanocomposite grouting materials and the related controlled grouting technology. As compared with the commonly used silicate-sulpho-aluminate composite cement, which is characterized by relatively poor rheological property, quick setting time and low strength, the most suitable nano-material with proper reactants were selected intentionally to improve the mentioned attributes of composite cement. Due to the setting time and strength of the targeted cement slurry behaving with poor performance of harmonization to engineering construction problems, hydration synergistic effect of these composites were investigated in our experiments. Results showed that the properties of grouting materials, including initial fluidity, setting time, ideal right-angle thickening, and early strength and late strength were sufficient to produce an expected grouting application. It is therefore advocated that the refined grouting material could provide a better solution to fix grouting problems in complex ground cementing operations.展开更多
Deep shale gas reservoirs being developed by SINOPEC are characterized by significant buried depths, high rock strengths, high temperatures and pressures, multiple layers, low ROPs, prolonged drilling time and prohibi...Deep shale gas reservoirs being developed by SINOPEC are characterized by significant buried depths, high rock strengths, high temperatures and pressures, multiple layers, low ROPs, prolonged drilling time and prohibitoryhigh costs. All of these factors may negatively affect the economic and effective development of shale gas. Under such circumstances, existing drilling techniques for deep shale gas around the world have been reviewed to highlight technical challenges in deep shale gas drilling in China. With consideration to the previous drilling operations of SINOPEC for deep shale gas, technical solutions for deep shale gas drilling have been proposed with regard to the optimization of casing programs, enhanced drilling, trajectory control, high-density oil-based drilling fluid, cementation for deep shale gas development and other aspects. Some of these research findings have been deployed with great successes in Pingqiao, Jiangdong Block in the 2nd Phase of Fuling Project, Dingshan Block and other blocks with deep shale gas development. Among them, Well JY-74-2HF has had a drilling time of only 54.25d, whereas Well JY-187-2HF has a TVD up to 4024.14m. Relevant research results may provide valuable guidance and references for the optimization of drilling programs andthe enhancement ofdrilling ef^ciency for deep shale gas development.展开更多
基金funded by National Natural Science of China (Grant Nos.41672362)Key Projects of Sichuan Provincial Department of Education (Grant No.16ZA0099)the State Key Laboratory of Geohazard Prevention & Geoenvironment Protection (Grant No.SKLGP2017Z011)
文摘Improvement of the fluidity and setting time of grouting materials has been recognized as an effective approach of seepage prevention in foundation works, and it is quite common to be used for handling severe leakages in complex ground conditions, such as loose, broken and fully fissured stratum. For the purposed of better meeting the engineering requirements, experimental studies were conducted in this study with focus on the nanocomposite grouting materials and the related controlled grouting technology. As compared with the commonly used silicate-sulpho-aluminate composite cement, which is characterized by relatively poor rheological property, quick setting time and low strength, the most suitable nano-material with proper reactants were selected intentionally to improve the mentioned attributes of composite cement. Due to the setting time and strength of the targeted cement slurry behaving with poor performance of harmonization to engineering construction problems, hydration synergistic effect of these composites were investigated in our experiments. Results showed that the properties of grouting materials, including initial fluidity, setting time, ideal right-angle thickening, and early strength and late strength were sufficient to produce an expected grouting application. It is therefore advocated that the refined grouting material could provide a better solution to fix grouting problems in complex ground cementing operations.
文摘Deep shale gas reservoirs being developed by SINOPEC are characterized by significant buried depths, high rock strengths, high temperatures and pressures, multiple layers, low ROPs, prolonged drilling time and prohibitoryhigh costs. All of these factors may negatively affect the economic and effective development of shale gas. Under such circumstances, existing drilling techniques for deep shale gas around the world have been reviewed to highlight technical challenges in deep shale gas drilling in China. With consideration to the previous drilling operations of SINOPEC for deep shale gas, technical solutions for deep shale gas drilling have been proposed with regard to the optimization of casing programs, enhanced drilling, trajectory control, high-density oil-based drilling fluid, cementation for deep shale gas development and other aspects. Some of these research findings have been deployed with great successes in Pingqiao, Jiangdong Block in the 2nd Phase of Fuling Project, Dingshan Block and other blocks with deep shale gas development. Among them, Well JY-74-2HF has had a drilling time of only 54.25d, whereas Well JY-187-2HF has a TVD up to 4024.14m. Relevant research results may provide valuable guidance and references for the optimization of drilling programs andthe enhancement ofdrilling ef^ciency for deep shale gas development.
