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The lacustrine dark shale deposits of the Upper Cretaceous Qingshankou Formation in the Central Depression of Songliao Basin contain a considerable amount of shale oil resources, among which the shale oil exploration of the Qingshankou Formation in the Qijia-Gulong Sag has made a major breakthrough. In this paper, methods of sealed thermal release, combined with organic solvent extract and Rock-Eval, has been used for the comprehensive evaluation of shale oil-bearing capacity of the Qingshankou Formation. The TOC of shales from the Qingshankou Formation in the study area range from 1.48% to 6.97% with an average value of 3.40%. The values of Tmax range from 440 ℃ to 453 ℃ with an average of 448 ℃ for the samples after extraction, and the production index ranges from 0.28 to 0.67, indicating a middle stage of oil generation window. The shale oil contents of the studied samples range from 4.00 mg/g to 19.49 mg/g with an average value of 13.74 mg/g. The contents of free oil range from 3.41 mg/g to 13.63 mg/g with an average value of 8.70 mg/g; while the content of adsorbed oil ranges from 0.60 mg/g to 9.43 mg/g with an average value of 5.04 mg/g. Free oil is made up of restricted oil and movable oil in the proportion of 1∶1. The content of restricted oil of the studied samples ranges from 1.81 mg/g to 8.49 mg/g with an average of 4.15 mg/g; while the content of movable oil ranges from 1.36 mg/g to 11.05 mg/g with an average of 4.55 mg/g. The movable oil resource is 12 kg/m3 based on the average content of mobile oil, which reveals good resource potential of movable shale oil in the first member of Qing-shankou Formation of the Sanzhao Sag.

In view of strong heterogeneity and complex formation and evolution of organic pores, field emission scanning electron microscopy (FESEM), Raman spectrum and fluid injection + CT/SEM imaging technology were used to study the macerals, organic pores and connectivity of organic pores in the lower Paleozoic organic-rich shale samples from Southern China. Combined with the mechanism of hydrocarbon generation and expulsion and pore forming mechanism of organic matter-based activated carbon, the relationships between organic pore development and the organic matter type, hydrocarbon generation process, diagenesis and pore pressure were explored to reveal the controlling factors of the formation, preservation and connectivity of organic pores in shale. (1) The generation of organic pores goes on through the whole hydrocarbon generation process, and is controlled by the type, maturity and decomposition of organic matter; the different hydrocarbon generation components and differential hydrocarbon-generation evolution of kerogen and solid asphalt lead to different pore development characteristics; organic pores mainly develop in solid bitumen and hydrogen-rich kerogen. (2) The preservation of organic pores is controlled by maturity and diagenesis, including the steric hindrance effect of in-situ hydrocarbon retention, rigid mineral framework formed by recrystallization, the coupling mechanism of pore-fluid pressure and shale brittleness- ductility transition. (3) The Ro of 4.0% is the maturity threshold of organic pore extinction, the shale layers with Ro larger than 3.5% have high risk for shale gas exploration, these shale layers have low gas contents, as they were in an open state before uplift, and had high hydrocarbon expulsion efficiency and strong aromatization, thus having the “congenital deficiency” of high maturity and pore densification. (4) The pores in the same organic matter particle have good connectivity; and the effective connectivity between different organic matter pores and inorganic pores and fractures depends on the abundance and distribution of organic matter, and development degree of pores and fractures in the shale; the accumulation, preservation and laminar distribution of different types of organic matter in high abundance is the prerequisite for the development and connection of organic pores, grain margin fractures and bedding fractures in reservoir.

Organic matter-hosted pores provide reservoir space and migration pathways for shale gas. The evolution of organic matter-hosted pores (OM pores) of different macerals from Longmaxi shale with a wide variety of thermal maturities has been investigated using field emission scanning electron microscopy (FE-SEM). The Longmaxi shale contains rare graptolites which are the main component of structured organic matter. No OM pores occur in graptolite fragments, irrespective of thermal maturity. OM pores locally developed in graptolite fragments are formed from hydrocarbon generation of organic matter which was replaced by macromolecular material from surrounding sediment or in situ polymerized by lipids from the organism itself. Solid bitumen is not only the major organic component in the Longmaxi shale, but also the main host of OM pore development. The diagenesis of fine-grained sediments and thermal evolution of organic matter have been combined with the morphology of solid bitumen to distinguish pre-oil solid bitumen and post-oil solid bitumen. The post-oil solid bitumen is dominant. The evolution of OM pores within solid bitumen is closely related to thermal maturity. Generally, OM pores within solid bitumen become greater as thermal maturity increases. During the mature to early postmature (GRo < 2.3%) stages, OM pores within solid bitumen are not well developed probably due to the masking by oil and bitumen generated from organic matter. OM pores within solid bitumen are well developed during the late postmature to early overmature (2.3% < GRo < 4.5%) stages, with two main types being spongy and bubble-shaped. For organic-rich Longmaxi shale, the contribution of OM porosity to total porosity is more than 50%. During the late overmature (GRo>4.5%) stage, organic matter carbonization will cause intense damage to shale pores so that the exploration risk of shale gas increases.

The source rock quality, organic pore structure, occurrence state and sealing mechanisms of shale gas in the Ordovician Wufeng – SilurianLongmaxi Formation (O3w-S1l), Fuling region, Sichuan Basin were studied using a series of techniques including ultra-microscopic organic maceral identification, FIB-SEM, high temperature/pressure isothermal adsorption and isotopic age dating of noble gas. The results show that: (1) O3w-S1l organic-rich shale was mainly formed in a sedimentary environment with high productivity in surface water and hypoxia in bottom water, which can be divided into two sections according to TOC. The lower section (TOC≥3%) is mainly composed of graptolite, phytoplankton, acritarch, bacteria and solid bitumen. Graptolite is the main contributor to TOC, but the shale gas is mainly derived from hydrogen-rich organic matter such as phytoplankton, acritarch and pyrolysis of liquid hydrocarbons produced by hydrogen-rich organic matter. (2) Organic pores, as principal reservoir space for shale gas, exist in hydrogen-rich organic matter and solid bitumen. The graptolites and plenty of other organic matter stacking distribution in lamina provide both reservoir space for supplement and effective pathways of connected pores for shale gas. (3) Shale gas in Fuling region is in supercritical state and dominated by free gas. The match of formation time of closed shale gas system and gas-generation peak, as well as slight alteration degree of sealing conditions in the later stage, are key factors controlling the retention and accumulation of shale gas in the regions with high thermal maturity and complex tectonic background. Adsorption, capillary sealing and slow diffusion of shale are the main microscopic mechanisms for the retention and accumulation of shale gas. It thus can be seen that the generation and accumulation of marine shale gas with high thermal maturity in complex structure areas is controlled jointly by anoxic depositional environment, excellent hydrocarbon rock quality, superior reservoir space and favorable sealing conditions. Key words: Sichuan Basin, Fuling gas field, shale gas, hydrocarbon-forming organisms, reservoir space, occurrence state, sealing mechanism

Background and objective The CIK cell is one of the most important means of the adoptive cellular immunotherapy, and it is a hotspot of which to simplify its culture procedure and to promote its inhibition rate. The aim of this study is to observe the biological function of the CIK cells cultivated by the recombinant human fibronectin (RN) and to establish an effective and simple way of cells expansion. Methods We separated the mononuclear cells (PBMCs) in 50 mL peripheral blood from 10 healthy persons with density gradient centrifugation in the lymphocyte-separating medium, and the PBMCs were divided into two groups, of which were cultivated by RN-introduced and conventional method separately. Then we estimated the proliferation ability, and analyzed the immunologic type, IFN-γ, IL-4, perforin and granzyme B of them with flow cytometry. Besides that, we tested the inhibition rate of CIKs cells to four kinds of human lung cancer cell lines in vitro by MTT assay. Results The RN-induced group had a higher proliferation rate that was 2.0-3.5 times of the conventional group, and there was an obvious statistical difference between the two (P < 0.05). The proliferation rates of CD3+CD16+CD56+T cells in each group were 3 778 and 2 068 times of the initial number, respectively. There was also a higher percentage of CD3+CD8+T cells in RN-induced group (P < 0.05), while the percentage of CD3+CD4+T cells had no significant statistical difference (P > 0.05). We found a similar inhibition rate of the CIK cells to all this human lung cancer cell lines (P >0.05). The cells which secreted IFN–γ increased, while the cells which secreted IL-4 did not. The cells which secreted granzyme B and perforin were positive. Conclusion It is an effective and simple way to cultivate the CIK cells with RN, which should be adopted.

Background and objective The CIK cell is one of the most important means of the adoptive cellular immunotherapy, and it is a hotspot of which to simplify its culture procedure and to promote its inhibition rate. The aim of this study is to observe the biological function of the CIK cells cultivated by the recombinant human fibronectin (RN) and to establish an effective and simple way of cells expansion. Methods We separated the mononuclear cells (PBMCs) in 50 mL peripheral blood from 10 healthy persons with density gradient centrifugation in the lymphocyte-separating medium, and the PBMCs were divided into two groups, of which were cultivated by RN-introduced and conventional method separately. Then we estimated the proliferation ability, and analyzed the immunologic type, IFN-γ, IL-4, perforin and granzyme B of them with flow cytometry. Besides that, we tested the inhibition rate of CIKs cells to four kinds of human lung cancer cell lines in vitro by MTT assay. Results The RN-induced group had a higher proliferation rate that was 2.0-3.5 times of the conventional group, and there was an obvious statistical difference between the two (P<0.05). The proliferation rates of CD3+CD16+CD56+T cells in each group were 3 778 and 2 068 times of the initial number, respectively. There was also a higher percentage of CD3+CD8+ T cells in RN-induced group (P<0.05), while the percentage of CD3+CD4+T cells had no significant statistical difference (P>0.05). We found a similar inhibition rate of the CIK cells to all this human lung cancer cell lines (P>0.05). The cells which secreted IFN-γ increased, while the cells which secreted IL-4 did not. The cells which secreted granzyme B and perforin were positive. Conclusion It is an effective and simple way to cultivate the CIK cells with RN, which should be adopted. [ABSTRACT FROM AUTHOR]