The preparation, characterization, and adsorption characteristics of lignin/silica nanocomposites are described. The nanocomposites were obtained from cellulosic ethanol residue (CER) by an in situ method. The lignin was used as a structure directing reagent, and sulfuric acid as precipitating reagent during the synthesis of lignin/silica nanocomposites. The effects of pH on the properties of the nanocomposites have been investigated in detail. The prepared nanocomposites were characterized by the FT-IR, SEM, TG-TGA, XPS and low-temperature nitrogen sorption methods. Adsorption capacities and adsorption behaviors of selected lignin/silica nanocomposite, lignin, and silica for Methylene Blue (MB) were also studied, respectively. The results indicated that the lignin/silica nanocomposite is a good candidate for a biosorbent, providing a potential route for the high value-added utilization of CER.

The largest Precambrian gasfield in China has been found from the Ediacaran (Sinian) carbonates in the central Sichuan Basin. The deep ancient reservoirs were generally attributed to the high-energy mound-shoal body in the carbonate platform. However, there is still little understanding on the distribution of the mound-shoal bodies that hampers further gas exploitation from the deep subsurface. Based on the seismic data, a large strike-slip fault system was identified by new 3D seismic data in the central Sichuan Basin. Further, it was found that the strike-slip fault had some effects on the mound-shoal bodies of the Ediacaran Dengying Formation. First, the platform margin was divided by strike-slip faults into three distinct segments to show two weak-rimmed margins and one interbedded rimmed margin. Second, the platform margin could be offset or migrated with the strike-slip faults. Third, there is varied margin thickness across the strike-slip fault zone. In the inner platform, more carbonate mound-shoal bodies developed behind the weak-rimmed margin that was divided by the strike-slip fault zones. In addition, the mound-shoal bodies may be separated by faulted sag. Further, the mound-shoal bodies may have developed along the faulted higher position in one side of the strike-slip fault zone. These patterns of the mound-shoal bodies suggest that the strike-slip fault had an important role in the sedimentary microfacies’ diversity in the intracratonic carbonates. The low displacement of the strike-slip fault is chiefly responsible for a weaker controlling effect on the microfacies change in the intracratonic basin rather than other tectonic settings.

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The largest Precambrian gasfield in China has been found in the central Sichuan Basin. It has been assumed as an Ediacaran (Sinian) mound–shoal, microfacies-controlled, dolomite reservoir. However, the extremely low porosity–permeability and heterogeneous reservoir cannot establish high production by conventional development technology in the deep subsurface. For this contribution, we carried out development tests on the fractured reservoir by seismic reservoir description and horizontal well drilling. New advances have been made in recent years: (1) the prestack time and depth migration processing provides better seismic data for strike-slip fault identification; (2) seismic planar strike-slip structures (e.g., en échelon/oblique faults) and lithofacies offset together with sectional vertical fault reflection and flower structure are favorable for strike–slip fault identification; (3) in addition to coherence, maximum likelihood and steerable pyramid attributes can be used to identify small strike-slip faults and for fault mapping; (4) fusion attributes of seismic illumination and structural tensor were used to find fractured reservoir along fault damage zone; (5) horizontal wells were carried out across the strike-slip fault damage zone and penetrated fractured reservoir with high production. Subsequently, a large strike-slip fault system has been found throughout the central intracratonic basin, and the “sweet spot” of the fractured reservoir along the strike-slip fault damage zone is widely developed to be a new favorable domain for high-production development. There is still a big challenge in seismic and horizontal well technology for the economical exploitation of the deep fractured reservoirs. This practice provides new insight in the deep tight matrix reservoir development.

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