Heavy oil is an important resource in current petroleum exploitation, and the chemical composition information of heavy crucial for revealing its viscosity-inducing mechanism solving practical exploitation issues. In this study, techniques high-temperature gas chromatography high-resolution mass spectrometry equipped with electrospray ionization source were applied to reveal typical oils from western, central, eastern China. The results indicate that these display significant variations...

The main aim of this study was to utilize remote sensing data establish regression models through machine learning predict locust density in the upcoming year. First, a dataset for monitoring grassland constructed based on meteorological and multi-source area. Subsequently, an SVR (support vector regression) model, BP neural network random forest model with PCA (principal component analysis), deep belief were built dataset. experimental results show that had best prediction performance among...

Most heavy crude oils underwent biodegradation and generated a significant amount of naphthenic acids. Naphthenic acids are polar compounds with the carboxylic group considered as major factor affecting oil viscosity. However, relationship between molecular composition viscosity is not well understood. This study examined "clean" low contents heteroatoms but had high content were fractionated by distillation caustic extraction. The was characterized high-resolution Orbitrap mass...

Ketone compounds are oxidation products of crude oil in the in-situ combustion (ISC) process. Revealing molecular composition ketones can provide theoretical guidance for understanding process and valuable clues studying state reservoir. In this study, low-temperature (LTO) processes were simulated thermal experiments to obtain thermally oxidized at different temperatures (170 °C, 220 270 320 °C). A combination chemical derivatization positive-ion electrospray (ESI) Fourier transform ion...

Low-temperature oxidation (LTO) is the main reaction that affects fuel formation in in-situ combustion process, which has important significance for subsequent propulsion and successful extraction of crude oil. In this study, heavy oil was subjected to LTO reactions at different temperatures. Three types products with varying depths were characterized terms number oxygen atoms polarity molecule reveal low-temperature process Ketone compounds acid polyoxides phase deep a higher coke...

Abstract Aiming at the deformation characteristics of surrounding rocks in underground powerhouse area a hydropower station Western China, finite difference method is used for numerical calculation, and assistant modeling software to realize refined complex surface, which effectively improves simulation accuracy. The results show that stress level low, small, basically stable. However, plastic zone has trend transfixion, so it necessary adjust spacing powerhouse.

Abstract Traditional analysis of landslide evolution discipline requires particular on-site investigation, which not only consumes a lot manpower and material resources, but is also very inefficient. With the development small drone aerial photography technology, method based on whole area measurement becomes possible. This paper uses rapid digital photogrammetry technology in recent years to monitor surface deformation Qinyu landslide, conducts an in-depth study its evolution. The results...

Abstract Efficiency in drilling operations is closely linked to the accurate estimation and control of Rate Penetration (ROP). This study presents a thorough comparative analysis diverse ROP calculation methods, including Low Pass Filter, Kalman Sliding Mode several others, all which are utilized extract values from raw sensor measurements. The objective comprehensively evaluate performance, advantages, limitations each method, specifically focusing on their ability efficiently process...

Abstract In consideration of the challenges SAGD process such as high watercut, elevated temperature produced fluid, and heat loss to overburden layer, combined CO2 sequestration electrical heating assisted gravity drainage (CSEAGD in short) is taken into enhance heavy oil production, especially for water sensitive reservoirs well, condition short offshore desert. a typical CSEAGD process, two parallel horizontal wells are drilled injection well production respectively, both serve electrodes...

In situ combustion (ISC) has attracted extensive attention in the development of heavy oil reservoirs because its high recovery efficiency and low energy consumption. The ISC been successfully implemented PetroChina Xinjiang oilfield. However, due to complexity composition process itself, molecular changes have not well characterized field samples. this study, we used gas chromatography–mass spectrometry (GC–MS) high-resolution Fourier transform ion cyclotron resonance mass analysis evaluate...

When the tunnel is excavated through water-rich fault, it easy to cause problems of water surge and instability face tunnel. The advanced curtain grouting can effectively improve rock mass quality permeability fault broken zone, ensure safety construction. In view this, MADIS-GTS finite element software used establish dynamic excavation models under conditions no grouting. deformation seepage characteristics palm surface were compared analysed determine fortification length, optimal...

It remains controversial whether the influence of hydrothermal fluids on dolomite reservoirs is dominated by dissolution or precipitation. In this study, multistage Lower Ordovician Yeli-Liangjiashan Formation in Chengdao-Zhuanghai area was investigated based petrographic observations and geochemical analyses, with an emphasis temporal relationships among dolomitization, pore formation, fluid activities determined situ U-Pb dating. The δ18O, δ13C, 87Sr/86Sr data indicate that genesis...

Using RMR surrounding rock classification method, the quality of underground main powerhouse a hydropower station is evaluated with small evaluation unit. The results show that mainly Grade III, and II IV develop intermittently depth powerhouse, there no I or V distribution. Secondly, setting smaller section conducive to improve accuracy better grasp distribution different grades in area.

Abstract Initial geostress field is an important factor affecting the stress distribution, displacement and failure mode of surrounding rock underground engineering, also one indexes design for works, especially large hydropower projects. At present, method to obtain mainly based on measured in-situ stress, however some projects are lack measurement data. To solve this problem, we inversed regional tectonic firstly, then extracted boundary load project area from fitted embedded cavern be...

Abstract Advanced support is the key measure for tunnel passing through weak broken surrounding rock. As a common advanced method, small conduit grouting technology can improve physical and mechanical properties of rock mass, enhance parameters, effectively suppress deformation Based on diversion project in west China, this paper comprehensively evaluates sensitivity parameters reinforcement based multi-factor analysis order to provide reference optimization scheme.

Abstract In the engineering fact that excavation will lead to deterioration of rock parameters in damage zone tunnel, based on a diversion tunnel by simulating continuous dynamic adjustment process surrounding parameters, law deep buried soft is studied. It considered damaged area constructed TBM process. After excavation, angle friction φ increases, cohesive strength C decreases, and supporting structure have limiting effect parameters.