The Influence of Extractable Organic Matter on Pore Development in the Late Triassic Chang 7 Lacustrine Shales, Yanchang Formation, Ordos Basin, China

To investigate the influence of extractable organic matter （EOM） on pore evolution of lacustrine shales, Soxhlet extraction, using dichloromethane, was performed on a series of Chang 7 shale samples （Ordos Basin, China） with vitrinite reflectance of 0.64% to 1.34%. Low-pressure gas adsorption experiments were conducted on the samples before and after extraction. The pore structure parameters were calculated from the gas adsorption data. The results show complex changes to the pore volumes and surface areas after extraction. The pore development of both the initial and extracted samples is strongly controlled by total organic carbon （TOC） content. Micropores developed mainly in organic matter （OM）, while mesopores and macropores predominantly developed in fractions other than OM. The influence of EOM on micropores is stronger than on mesopores and macropores. Organic solvents with a higher boiling point should be used to explore the effect of EOM on pore structure in the future.

Sedimentology and Sequence Stratigraphy of Marine to Lacustrine Deltaic Deposits in a Craton Basin and Their Controlling Factors: Shan 2 Member–He 8 Member(Guadalupian–Lopingian, Permian), Southeast Ordos Basin, North China

The Shan 2 Member, Shan 1 Member and He 8 Member of the Mid-Late Permian Shanxi and lower Xiashihezi formations, in the southeastern Ordos Basin, together comprise -150 m of deltaic deposits. This sequence records an overall evolution from deep marine environment to shallow lake associated with braided river, braided river delta and meandering river delta. Core description, well log interpretation, and stable isotope analysis, including carbon, oxygen and strontium, were conducted to understand the sedimentary evolution of Shan 2 to He 8 Member. The Shanxi Formation, which consists of the Shan 2 and Shan 1 members, is characterized by a tidal-influenced meandering river delta environment and a higher j13C value and S7Sr/S6Sr ratio and a lower jlSo value. The He 8 Member, the basal part of the Xiashihezi Formation, is featured by a braided river to braided river delta system and a lower j13C value, S7Sr/S6Sr ratio, and a higher jlSo value. Four third-order depositional sequences separated by five sequence boundaries are determined. Coarsening upward sequences of the Shan 2 Member-He 8 Member indicate a general regression trend, which can be correlated to global sea-level fall occurring during the Roadian-Wuchiapingian, as also evidenced by previous published zircon U-Pb results. The coal-bearing sequence （Shanxi Formation） to non-coal-bearing sequence （He 8 Member）, as well as a decrease of 87Sr/86Sr, suggest a trend from humid to arid climates. A combined effect of sea-level drop and a small uplift at the end of Shanxi Formation are proposed.

Wear Resistances of CO_2 Corrosion Product Films in the Presence of Sand Particles

Wear resistances of CO2 corrosion product films formed on P110 carbon steel at different CO2 partial pressures were investigated in water sand two-phase flow by weight loss method, and the microstructures and compositions of corrosion product films were analyzed by scanning electron microscope(SEM) and X-ray diffraction(XRD), respectively. The results showed that the wear rate of CO2 corrosion product films increased until a maximum and then decreased with the increasing of the film-forming pressure, and the maximum occurred at 2 MPa. However, the maximal corrosion rate and the loose and porous CO2 corrosion product films were obtained at 4 MPa. And the wear rate decreased and then went to be flat with increasing test time. Furthermore, the microstructures and compositions of corrosion product films and the impact and wear of sand particles played an important role on wear resistances. In addition, the wear rate and corrosion rate were fitted by cubic polynomial, respectively, which were well in accordance with the measured results.

Oil charging history and pathways of the Ordovician carbonate reservoir in the Tuoputai region,Tarim Basin,NW China

Geochemical analysis of 64 oils sampled from an Ordovician carbonate reservoir in the Tuoputai region was undertaken to study the composition of molecular markers. All the oils have similar geochemical characteristics and belong to a single oil family. They are presumed to derive from the same source kitchen and have similar oil charging history. A histogram of homogenization temperatures(Th) of aqueous inclusions in reservoir rocks shows a bimodal distribution pattern, indicating that the Ordovician reservoir has been charged twice. Coupling the measured Th(°C) with the burial and geothermal histories reconstructed using 1D basin modeling, we relate the homogenization temperature to the relevant geological ages: i.e.,425–412 and 9–4 Ma, corresponding to the Middle to Late Silurian and the Miocene to Pliocene, respectively. The oil filling orientation and pathways are traced using molecular indicators related to alkyldibenzothiophenes and benzo[b]naphthothiophenes. The oil charging orientation is from south to north generally. It can be predicted that the Ordovician reservoirs were sourced from a kitchen located to the south of the Tuoputai region, most probably between the Awati and Manjiaer Depressions. Traps located in the southern side of the Tuoputai region, along the oil charging pathways, should therefore be preferred oil exploration targets.

Study on attrition of spherical-shaped Mo/HZSM-5 catalyst for methane dehydro-aromatization in a gas–solid fluidized bed

As a potential methane efficient conversion process,non-oxidative aromatization of methane in fluidized bed requires a catalyst with good attrition resistance,especially in the states of high temperature,longtime rapid movement and chemical reaction.Existing evaluation methods for attrition resistance,such as ASTM D5757 and Jet Cup test,are targeted for fresh catalysts at ambient temperature,which cannot well reflect the real process.In this study,spherical-shaped Mo/HZSM-5 catalyst prepared by dipping and spray drying was placed in a self-made apparatus for attrition testing,in which the catalyst attrition under different system temperatures,running time and process factors was investigated with percent mass loss(PML),particle size-mass distribution(PSMD)and scanning electron microscope(SEM).Carbon deposition on the catalyst before and after activation,aromatization and regeneration was analyzed by thermogravimetry(TG),and the attrited catalysts were evaluated for methane dehydro-aromatization(MDA).The results show that the surface abrasion and body breakage of catalyst particles occur continuously,with the increase of system temperature and running time,and make the PML rise gradually.The process factors of activation,aromatization and regeneration can cause the catalyst attrition and carbon deposits,which broaden the PSMD in varying degrees,and the carbon-substances on catalysts greatly improve their attrition resistance at high temperature.Catalyst attrition has a certain influence on its catalytic performance,and the main reasons point to particle breakage and fine powder escape.

Optimization of a High-pressure Water-Powder Mixing Prototype for Offshore Platforms

A new device is designed to promote the mixing of high-pressure water jets and powders in typical industrial applications.The water and powder mixing devices traditionally used on offshore platforms are detrimentally affected by the geometrical configuration of the water nozzle and the powder spraying pipe,which are parallel,resulting in small intersecting volumes of liquid and powder.By allowing the related jets to intersect,in the present work the optimal horizontal distance,vertical distance and intersection angle are determined through a parametric investigation.It is also shown that such values change if the number of water layers is increased from one to two.In such a case,the water and powder intersection volume can be greatly increased because the trajectory of the dry powder particles becomes more chaotic.

Closed-system pyrolysis-based hydrocarbon generation simulation and gas potential evaluation of the Shanxi Formation shales from the Ordos Basin, China

The Shanxi Formation(Shan 1 and Shan 2 Members)shales show good prospects in shale gas development in the Yan'an area of Ordos Basin.Based on the simulation experiment of hydrocarbon generation of low maturity shale samples,the hydrocarbon generation characteristics of shale samples was studied systematically.Then,combined with the geochemical analysis of shale and gas generation simulation,shale gas potential was evaluated.The results reveal that Shan 1 and Shan 2 shale samples are favorable for shale gas enrichment by and large,with C_(1)-C_(5) maximum yields of 146.96-160.83 mg/g TOC and 148.48-148.67 mg/g TOC respectively at a heat rate of 20℃/h and 2℃/h.The Shan 1 and Shan 2 shales are basically the same in terms of organic carbon production potential of each unit.The carbon isotopic composition of alkane gas reveals that heteroatomic compounds(NSOs)cracking is an important mechanism for shale gas generation of Shanxi Formation shales,and conducive to gas generation at highto over-mature stages.Given thermal history and kinetic parameters of hydrocarbon generation,the shales of Shanxi Formation reached the maximum gas production potential in the Late Cretaceous,with a maximum yield of 160.3 mg/g TOC under present geological conditions.During geological history,the Shanxi Formation shales went through high-to over-maturity evolution,mainly producing dry gas,and their gas generation capacity was controlled by the organic matter abundance and cracking capacity.The gas generation potential of Shan 2 shale is higher than that of Shan 1,due to its higher TOC.

Pore throat characteristics of tight sandstone of Yanchang Formation in eastern Gansu,Ordos Basin

An important factor to evaluate reservoir quality is the pore-throat size.However,the strong heterogeneity makes it difficult to characterize the pore-throat distribution in tight reservoirs.The field emission scanning electron microscope(FESEM),high pressure mercury injection and rate-controlled mercury injection are used to investigate the pore-throat size distribution in tight sandstone reservoirs of Member 7 of the Yanchang Formation in eastern Gansu,Ordos Basin,and studies of the pore throat size controlling on physical property of the tight sandstone reservoirs are also carried out.The result shows that the pore type is mainly dominated by the residual intergranular pore,dissolution pore,micropore and a few micro-fractures;the high-pressure mercury injection experiment indicates that the pore-throat size ranges from 0.0148 μm to 40mm,the pore throat more than 1 mm is less;the ratecontrolled mercury injection experiment reveals that for samples with different physical properties,the pore radius mainly varies from 80 μm to 350 μm;the throat radius exhibits the strong heterogeneity,and is from 0.12 μm to 30μm;the pore-throat size can be effectively characterized by combination of high-pressure and rate-controlled mercury injections,and it varies from 0.0148 μm to 350 μm.The permeability is mainly controlled by the large pore throat(>R_(50))which accounts for a small proportion;in the tight sandstone with the permeability greater than 0.1 mD,the permeability is mainly controlled by the micropore and mesopore;in the tight sandstone with the permeability smaller than 0.1 mD,the permeability is mainly controlled by the nanopore and micropore;the proportion of small pore throat increases with reduction of permeability,it is important that the small pore throat influences the reservoir storage property though its effect on permeability are small.

Synthesis and Characterization of Polyaniline/Partially Phosphorylated Poly(vinyl alcohol) Nanoparticles

The polyaniline/partially phosphorylated poly（vinyl alcohol）（PANI/P-PVA） nanoparticles were prepared by the chemical oxidative dispersion polymerization of aniline monomer in 0.5 mol/L HC1 aqueous media with the partially phosphorylated poly（vinyl alcohol） （P-PVA） as the stabilizer and co-dopant. The PANI/P-PVA nanoparticles were characterized by transmission electron microscopy （TEM）, Fourier transform infrared spectroscopy （FTIR）, thermal gravimetric analysis （TGA）, X-ray diffraction （XRD）, electrical conductivity measurements and re-dispersion stability testing. All the results were compared with the properties of the conventional polyaniline in the emeraldine salt form （PANI ES）. It was found that the feeding ratio of P-PVA obviously affected the morphology, re-dispersion stability and electrical conductivity of the PANI/P-PVA nanoparticles. When the feeding ratio of P-PVA ranged from 40 wt% to 50 wt%, the PANI/P-PVA nanoparticles showed spherical shape with good uniformity, significant re-dispersion stability in aqueous media and good electrical conductivity.