Shansi Tian

Research of CO 2 and N 2 Adsorption Behavior in K-Illite Slit Pores by GCMC Method

Understanding the adsorption mechanisms of CO2 and N2 in illite, one of the main components of clay in shale, is important to improve the precision of the shale gas exploration and development. We investigated the adsorption mechanisms of CO2 and N2 in K-illite with varying pore sizes at the temperature of 333, 363 and 393 K over a broad range of pressures up to 30 MPa using the grand canonical Monte Carlo (GCMC) simulation method. The simulation system is proved to be reasonable and suitable through the discussion of the impact of cation dynamics and pore wall thickness. The simulation results of the excess adsorption amount, expressed per unit surface area of illite, is in general consistency with published experimental results. It is found that the sorption potential overlaps in micropores, leading to a decreasing excess adsorption amount with the increase of pore size at low pressure, and a reverse trend at high pressure. The excess adsorption amount increases with increasing pressure to a maximum and then decreases with further increase in the pressure, and the decreasing amount is found to increase with the increasing pore size. For pores with size greater larger than 2 nm, the overlap effect disappears.

Correction Method of Light Hydrocarbons Losing and Heavy Hydrocarbon Handling for Residual Hydrocarbon (S1) from Shale

In China, hot researches on shale oil were raised by the important breakthrough of shale oil in America. Obviously, the first important issue is the actual shale oil resource potential of China, and the selection of the key appraisement parameter is vital to the shale oil resource amount. Among the appraisement parameters, the oil content parameter (S1) is the key one, but the evaluation result is generally lower because of light hydrocarbon losing and heavy hydrocarbon handling. And the more important thing is that the light hydrocarbon with small molecular weight is more recoverable, and therefore its amount is important to the total shale oil yields. Based on pyrolysis experiments and the kinetic model of hydrocarbon generation, correction factors and a model of light hydrocarbon losing and heavy hydrocarbon handling were established. The results show that the correction factor of heavy hydrocarbon handling is 3.2, and that of light hydrocarbon losing is controlled by kerogen type, maturity and hydrocarbon generation environment (closed or open).

The Research Progress on the Occurrence Mechanism of Detained Hydrocarbon

Swelling is a concept in polymer physics, which describes the phenomenon that cross-linked polymer don’t dissolve but swell in the solvent. In recent years, the initial migration/ expulsion of hydrocarbon based on the theory of polymer dissolution (solution theory polymer) and swelling method. The method was firstly introduced by Rittter. Ertas gave a swelling test technique for determining the retaining ability of kerogen. The existing data show that the degree of kerogen swelling capability decreases with the increase of burial depth and maturity, and has a close relationship with the attention of micro pores. Cai (2007) and Zhang (2008) used Ritter swelling technology prediction of hydrocarbon in the kerogen in hydrocarbon retention amount. The results show that Ritter, who seems too high an estimate of each component in the kerogen in hydrocarbon retention amount. According to Kelemen, at different temperatures, the swelling ratio of 30-150°C was slightly different. This temperature covered the geological conditions, and the vast bulk of hydrocarbon generation temperature range, which means 30°C under the measured swelling ratio (hydrocarbon retention capacity) can represent geological conditions of organic matter hydrocarbon generation of the vast most of the temperature range under different sets of points of kerogen and the swelling hydrocarbon retention characteristics. But it is still in the initial stage, is not perfect, the previous research methods cannot carry out the research of material differentiation.

Talk about the Difference and Connection between Conventional and Unconventional Oil

more oil and gas resources and it is decreasing continually, unconventional oil and gas with the large resource potential gradually become the new exploration areas. Unconventional oil has been attached great importance by countries and companies. It’ll become the inevitable trend of industry development that the extension from the conventional oil and gas to unconventional oil and gas in oil and gas exploration and development field. Conventional and unconventional oil and gas is obviously different in geological characteristics, the principle of gather, exploration methods, the evaluation of “dessert” area, the way of development, etc. Conventional hydrocarbon pools include structural reservoir, stratigraphic reservoir, lithologic reservoir, etc. Structural reservoirs mainly are isolated type or larger area of cluster type. Trap boundaries are visible. Reservoir space is mainly mm-micron grade pore system. The research object is trap and reservoir. The research core is trap and its effectiveness. Theory is based on theory of buoyancy accumulation. Unconventional oil and gas accumulation include the dense oil and gas, shale oil and gas, coal-bed methane, etc. Unconventional oil and gas mainly stays in situ or migrate short distance. The object of study is the hydrocarbon core and “dessert”. The core is the configuration of source and storage. Conventional oil and gas evaluation focuses on generation, reservoir, cap, trap, migration, and preservation –“six elements”-and the best matching relationship. It focuses on evaluation of high quality hydrocarbon source, favorable reservoir, efficient transportation systems and the scale of trap, etc. Unconventional oil and gas evaluation focuses on hydrocarbon source rock characteristics, lithology, physical properties, brittleness, oil-gas possibility, stressinduced anisotropy -“six characteristics”and the matching relationship. There are eight evaluation about “dessert” area, of which three keys indicators are more than 2% of TOC, high porosity (dense oil and gas>10%, shale oil and gas>3%) and micro fracture growth. The similarities of conventional and unconventional oil and gas are the same hydrocarbon source system, the same force of the primary migration, similar oil and isotope composition, etc in the same petroleum system. Conventional and unconventional oil and gas is correlative in genesis and symbiotic in space, displaying ordered aggregation of conventional and unconventional oil and gas.