Abstract:Jiyang Depression is an important Cenozoic oil and gas resource production base in eastern China，and the buried hill reservoir is an important reservoir type. The Mesozoic and Cenozoic tectonic movements play a key role in the formation mechanism and types of buried hill reservoirs. Based on the study of the dynamics of Indosinian movement，Yanshan movement and Himalayan movement and their tectonic responses，the formation mechanism of buried hills in Jiyang Depression was analyzed by synthesizing the tectonic evolution characteristics of different periods，and then types of reservoirs were explored. It was found that the combined actions of Indo-China movement，Yanshan movement and Himalayan movement make Jiyang Depression extruded，tensioned and strike-slipped，which is characterized by extrusion，tension and strike-slip structure responses such as unconformity of the stratum，anticline，reverse fault，inverted structure，negative reversal，and geese fault，etc. Reservoir type and distribution of buried hill reservoir are closely related to extrusion，tension and strike-slip movements. According to reservoir and reservoir control factors，buried hill reservoirs in Jiyang Depression are classified into 3 types including strata，fault block and compound reservoir，and can be further classified into nine subclasses further.

Abstract:The adsorption isotherm equation published by Langmuir in 1918 describes the relationship between cumulative adsorption rate and adsorption pressure under isothermal condition. However，it should be noted that the Langmuir equation is an empirical equation of isothermal cumulative adsorption based on the experimental data from a large number of adsorption isotherm experiments by adsorption instrument（made by mica sheet）using methane（CH4），nitrogen（N2），carbon monoxide（CO），carbon dioxide（CO2），oxygen（O2），argon（Ar），and other gases. This equation has two constants，a and b.CHEN Yuanqian published the derivation of adsorption isotherm equation in 2018. There are also two constants A and B for this equation. The research results indicate that the two constants in the adsorption isotherm equations proposed by Langmuir and CHEN both have important physical meanings. The constant A of CHEN’s equation and the constant a of Langmuir equation represent the limit of cumulative adsorption rate of the sample. The constant B of CHEN’s equation and the constant b of Langmuir equation represent the decreasing rate of adsorption capacity. AB of CHEN’s equation and ab of Langmuir equation represent the maximum of theoretical initial adsorption rate of the sample. Meanwhile，the dimensionless CHEN’s and Langmuir adsorption isotherm equation and adsorption isotherm equation at instantaneous pressure were proposed，and a method for determining the isothermal saturated adsorption pressure and isothermal saturated cumulative adsorption capacity was proposed. The application of 16 cases shows that the limit of adsorption rate of samples evaluated by CHEN’s equation and Langmuir equation was basically same. For evaluations of the decline rate of instantaneous pressure adsorption rate and the maximum theoretical initial adsorption capacity，the results of Langmuir equation were significantly different from those of CHEN’s equation. However，it should be noted that Langmuir equation is empirical，and its reliability is lower than CHEN’s equation.

Abstract:The Middle to Late Ordovician is an important period with abounding deep-water contour current activities in the western margin of Ordos Basin，and contour currents have significant impact on the morphological characteristics of reservoir and the distribution of hydrocarbon source rock in oil and gas systems. The Lower Kelimoli Formation in Zhuozisan area of Inner Mongolia was taken as an example in this paper，and the characteristics of contour current was analysed according to the previous studies and the oxygen and carbon isotopic test data of thin-bedded limestone. The results show that the thin-bedded limestone of Kelimoli Formation is deposited in a normal salinity seawater，where an oxygen isotope exchange balance exits between seawater and limestone during the limestone deposition，and the effect of limestone diagenesis on oxygen isotope is negligible. The paleo-water temperature measured according to the oxygen isotope data is in the range of 22.2 ℃ to 30.7 ℃ with an average as 26.4 ℃. According to the characteristics of high temperature and normal salinity of deep water during the sedimentary period，it is inferred that the Lower Kelimoli Formation in the study area may be isothermal current deposits caused by wind-sea currents，which belong to the surface ocean circulation. This discovery suggests that the Lower Paleozoic in western margin of Ordos Basin may develops self-generation self-storage contour current oil and gas reservoirs with a broad prospect of hydrocarbon exploration.

Abstract:The microscopic pore structure of tight oil reservoir rocks in Lucaogou Formation was investigated using high pressure mercury intrusion（HPMI），rate-controlled mercury intrusion（RCMI），and scanning electron microscopy（SEM）.RCMI can quantitatively distinguish the pore body and pore throat of the sample，and can accurately determine the pore size of the large pores. However，because of its lower mercury intrusion pressure，the RCMI cannot detect the small pores in the samples. HPMI with a higher mercury intrusion pressure can accurately determine the pore size of small pores of samples. The connected points of two techniques were obtained using interpolation method in the common measurable interval，and then the combination of HPMI and RCMI was used to obtain the overall pore size distribution of the tight oil reservoir rocks of Lucaogou Formation. The results demonstrate that the types of pores of the tight oil reservoirs in Lucaogou Formation are mainly intergranular pore，residual interparticle pores，and intercrystalline micropores. All the capillary pressure curves of these rock samples have no intermediate gentle section. The pore structure of these samples is complex，and the sorting is poor. The pore size distribution pattern of the tight oil reservoirs of Lucaogou Formation in Jimusaer Sag are bimodal. According to the pore size classification scheme proposed by LOUCKS，the nanopores with radii ranging between 0.07 and 1 μm are abundant. The radii of mesopores are around 120-150 μm，and the micropores are rare compared to nanopores and mesopores. Because HPMI and RCMI are based on the same physical procedure-mercury intrusion，the combination of these two techniques is an effective method to accurately obtain the overall pore size distribution of the tight oil reservoir rocks.

Abstract:No consensus has been reached on the depositional types in the 2nd sand group of middle Es3 Member in Fan162 and Fan3 Blocks of Daluhu Oilfield，Boxing Subsag. Based on cores，logging data，seismic data and analytical data，the sedimentary characteristics，sedimentary evolution and depositional model in the 2nd sand group of middle Es3 Member were systematically studied. The results show that hyperpycnal flows deposits in semideep-deep lake are regarded to mainly develop in the study area，and are characterized by：①wave cross-bedding and climbing ripples bedding formed by water flow；②a large amount of terrestrial material，such as black carbonaceous plant debris，reddish-brown mud boulder and layered mudstone；③a series of coarsening upward interval and fining upward interval always appear in pairs with inner erosion surface. The hyperpycnal flows are controlled by flood influx which transports sediments to the delta front in the Northern Luxi Uplift. Two-stage deposition caused by waxing and waning flows shows a depositional tendency from weak to strong and then to weak. The main body of hyperpycnal flow developed a lentoid filling model and the lofting facies subsided to form a set of rootless fine-grained sediments without homochronous channel in late deposition period. Based on comprehensive analysis of climate，topography，structure，etc.，the depositional model of“inner fan-middle fan-outer fan”was constructed.

Abstract:Kaolinite，as the main adsorbent carrier of clay minerals，cannot be ignored for its contribution to methane adsorption. The double-layer adsorption space model of kaolinite was established in the consideration of the unique 1∶1 double-layer crystal structure of kaolinite. Using the Grand Canonical Monte Carlo method，localized adsorption simulation of single methane molecule in kaolinite supercell and adsorption isothem simulation of methane in kaolinite were carried out to analyze the effects of kaolinite crystal structure，temperature，and moisture content on the adsorption behavior. The results show that the adsorption of methane on kaolinite silico tetrahedron（silicoxylated surface）is stronger than that of Al oxygen eight surface layer（aluminum oxygen hydroxylated surface）. Methane adsorbs on the alkoxylation surface with priority.The adsorbed methane is clustered in the position above the six membered ring hole of silicon tetrahedron and the adsorption with the triangular pyramid configuration is the most stable. The adsorption of methane on kaolinite at 280-400 K is consistent with Langmuir isothermal adsorption type and belongs to physical adsorption. The adsorption capacity and adsorption heat of methane decrease linearly with the increase of temperature. It is confirmed that the adsorption capacity at high temperature can be predicted according to low temperature. Before kaolinite is saturated with water，the presence of water does not change the adsorption trend and the type of methane adsorption，and it only reduce the amount of methane adsorption. When the water content increases from 0 to 20.94%，the adsorption capacity of methane is reduced by 35.06%.

Abstract:To investigate the geological conditions and resources potential of shale gas and coalbed methane（CBM）of Upper Permian Leping Formation in Qujiang syncline in Pingle Depression，relevant data of Well Quye1 including drilling，logging，organic geochemistry，petrology，and reservoir characteristics were analyzed，and the CBM and shale gas of Leping Formation were studied by in-situ desorption. The results show that the accumulated thickness of shale and coal in Laoshan member of Leping Formation are 183 m and 7 m，respectively，and the gas logging reveals that the gas-bearing strata is 356 m，the average total organic carbon content of black shale in Leping Formation is 2.98%，and the average reflectance of vitrinite is 1.88%. The shale is in high-overmature thermal evolution stage in which dry gas generates dominantly and the measured desorbed gas content is 2.1 m3/t. The coal seam in Leping Formation of Well Quye1 is medium-rank coal with high quality，large thickness of single stratum and high gas content.It is found that the gas bearing capacity of shale reservoirs of Leping Formation in Pingle Depression increases with the buried depth，which shows the typical characteristics of shallow shale gas.

Abstract:Based on the core，seismic，logging and experiment data，the control factors of sedimentary environment were analyzed，and the numerical simulation of reservoir sedimentary process was carried out to quantitatively characterize the reservoir distribution and evolution at different stages. The study results show that the initial parameters of numerical simulation of carbonate reservoir sedimentary process have a great influence on the reservoir distribution，and main parameters include accommodating space change，carbonate productivity，etc. In the vertical direction of BU Oilfield，the MB21 Member of Mishirif Formation can be divided into 6 layers includingⅠ-Ⅵ. High-energy sedimentary belt and low-energy sedimentary belt appear alternately. The lithology of high-energy sedimentary belt is mainly grain limestone on the top of LayerⅠ，while the lithology of low-energy sedimentary belt is mainly micrite limestone with micro-fracture on the bottom of Layer Ⅵ. The research results provide the geologic basis for the water injection development scheme of bottom injection and top production in BU Oilfield. Four wells have been drilled to build up the formation pressure and to alleviate the local pressure deficit，and the daily production rate of the Oilfield has increased by nearly 19%，and increases to 0.94×104 m3/d.

Abstract:Due to the limitation of oil production platform，it is difficult to carry out thermal recovery in offshore heavy oil reservoirs by steam injection. The technology of multi-thermal fluid has a great potential to develop the offshore heavy oil reservoirs because of its small equipment size. A long sand-pack tube model was used to analyze the influence of injection temperatures and fluid component on oil displacement by multihermal fluid，and then a 2D physical simulation with the similar scale was carried out to study the production performance and the distribution characteristics of temperature field.Finally，the mechanism of oil displacement was summarized. The results show that the best injection temperature is 250 ℃ and the best gas and steam ratio is 1∶3 for the multi-thermal fluid flooding. During the flooding，the steam chamber gradually advances from injection well to production well in a triangle mode. The whole process of flooding can be divided into four stages：start-up，displacement，steam channeling，and erosion. Among them，the highest oil production is from the displacement stage. The main mechanism of EOR involves thermal viscosity reduction，oil mobility increasing due to the dissolution of CO2，the formation of foam-like fluid during the precipitation of CO2 to increase the flow resistance of the gas phase and to improve the movability of crude oil.

Abstract:In order to accurately predict the shale gas productivity and guide the actual production，in the consideration of the permeability change caused by rock deformation and the viscous flow，surface diffusion and Knudsen diffusion of shale gas，and by coupling the geomechanical effect with the fluid flow，a mathematical model that comprehensively considers the stress sensitivity and the various percolation mechanisms of shale gas was proposed. The discrete fracture model was used to describe the microfractures and hydraulic fractures in the formation，and it was solve by finite element method. The results show that surface diffusion and Knudsen diffusion increase shale permeability and further increase the shale gas production. The stress-sensitive effect reduces the matrix permeability，resulting in a decrease in cumulative gas production.The larger surface diffusion coefficient and the Langmuir volume or the lower bottom hole pressure would increase the cumulative gas production of shale gas. For the shale gas reservoirs with a larger Langmuir volume，it is beneficial to reduce the pressure at the bottom of the well to reach a higher production potential. The simulation results of the model fit well with the actual historical production data，which verifies the correctness of the model.

Abstract:In order to rapidly evaluate or select oil productivity development projects，statistical analysis method was applied to thoroughly analyze the productivity development projects of new blocks，SINOPEC in 2007-2015. The main control factors of key reservoir engineering parameters influencing the development plans design were obtained for eight types of reservoirs including common heavy oil reservoirs，thermal recovery heavy oil reservoirs，low-permeability reservoirs，ultralow permeability reservoirs，fault-block reservoirs，complex fault-block reservoirs，fractured-vuggy carbonate reservoirs，and offshore reservoirs. These factors include reservoir type，geological reserves，oil-bearing area，reservoir depth，permeability，and oil viscosity，etc. Statistic models of reservoir parameters in eight types of reservoirs and productivity development indexes of single well were proposed as well. Daily oil production capacity of 106 productivity development units was evaluated rapidly according to the new deployed development blocks in 2016-2017 with 8 reservoir models. The results show that the rapid evaluation model can be used to judge the selection of productivity. The application of the model indicates that the reasonable application range should be known before the application and reservoir parameters should be selected carefully during the application to keep away to produce large errors.

Abstract:Problems on strata & well pattern appeared at extra high water cut stage in Daqing Oilfield，and contradiction should be relieved and development effect should be improved through adjustment. Physical modeling and numerical simulation were applied to understand the mechanisms of interbedded and plane contradiction at the extra high water cut satge.Based on the theoretical research，the technical and economic limits，principles，and pattern of strata & well pattern reconstruction were determined，the field trials was carried out in X pilot area，and the recovery efficiency increased from 51.30% to 56.79%. Research and practice on the strata & well pattern reconstruction in Daqing Oilfield indicate that the difference of permeability is the internal cause of interlayer and well interference，the uniformity of well space is the external cause of the well interference，which is the easiest to be artificially improved. The difference of water saturation affects flow among layers and wells under the action of the internal and external causes. Development effect can be improved by dividing strata and development object in more detail and by thickening well pattern appropriately.

Abstract:The binary compound flooding can dramatically improve oil recovery after water flooding. In order to have a better understanding of the enhanced oil recovery（EOR）mechanism of binary compound system，the synergistic effect of interfacial activity and emulsifying properties on EOR was studied. The physical simulation experiments，microscopic visualized displacement experiments，and nuclear magnetic resonance（NMR）experiments were applied，with the purpose to study the oil displacement effect of the systems with different interfacial activity and emulsifying properties，to clarify the change law of interfacial activity of the system during the percolation，and to illustrate the synergistic effect of interfacial tension and emulsification on enhancing oil recovery. Results show that because of the reservoir heterogeneity and the performance change of compound system，a lower interfacial tension between the system and oil may not get a better oil recovery. A high interfacial tension is negative to improve the displacement efficiency. However，a low interfacial tension results in an ignorable emulsification effect. When the oil-water interfacial tension and emulsifying properties match well，the residual oil in deep reservoir may be produced at low interfacial tension of the binary compound system. At the same time，oil droplets could plug large throats to change deep flow field distribution and to reduce remaining oil saturation of non-preferred stratum. All of these would reach the aim to dramatically enhance oil recovery.

Abstract:The use of flue gas-assisted gravity drainage technique（FGAGD）has achieved good application results in the foreign oilfields. A large amount of flue gas were produced in the process of heavy oil thermal recovery in Xinjiang Oilfield，and a large number of high-inclined and thick-layered oil reservoirs were distributed near the flue gas source. If these reservoirs can be developed with FGAGD，oil recovery will be enhanced obviously，and greenhouse gas emissions will be reduced to protect the ecological environment. To this end，through a detailed analysis of the successful production cases with GAGD in foreign countries，the application conditions of GAGD technique were summarized. On this basis，comprehensively considering the current resources situation in Xinjiang Oilfield and the availability of the evaluation method，the evaluation indexes and standard of reservoir selection for FGAGD were put forward and classified by the necessity and significance. The method of reservoir selection and evaluation for FGAGD was proposed. The reliability of the technique was then verified by applications to eleven oilfields. The method was applied to discuss the feasibility of FGAGD in the area around Hong153 in Xinjiang Oilfield from several aspects including the flue gas resource，well conditions，geological conditions according to the reservoir screening criteria. The final reservoir selection index with FGAGD was 9.39，which showed the feasibility of FGAGD in the area around well Hong153. The flue gas injection test was carried out at the top of the reservoir Hong153 in December 2017. A remarkable oil increase was observed in the surrounding well from 9.5 t/d to 20.3 t/d，which verified the correctness of the method.

Abstract:In order to quickly evaluate the production process and the development result of SAGD，six mathematical models which can be used as indexes to evaluate SAGD performance were proposed based on the injection and production data during SAGD and by using reservoir engineering methods. These six models include instantaneous steam oil ratio，cumulative steam oil ratio，cumulative production injection ratio，cumulative water steam ratio，water cut and cumulative steam retention ratio. Under the determined extreme instantaneous steam oil ratio，the variation between the degree of recovery factor and above evaluation indexes under different forecasting final-recovery factor were obtained to form standard templates.Then a promoted method used to evaluate SAGD development process and result was formed. This method was applied to the drainage area 15 of Long Lake Oilfield，Canada. The results show that the models of the instantaneous steam oil ratio， the cumulative production injection ratio and the cumulative water steam ratio can be used to dynamically characterize the effect of high water cut zone and top water zone on production. On the basis of initial recovery factor of 73%，the finally forecasted recovery factor can be increased to 80% if further adjustment methods are conducted.

Abstract:The effective prediction of the high production zone of the coalbed methane（CBM）is important to improve the single well production and the development benefits. In order to quantitatively evaluate the production capacity of the CBM reservoir，the gas-bearing index，desorption efficiency index of CBM，gas-water production efficiency index and production capacity index were defined through theoretical and statistical analysis of the CBM development data in southern Qinshui Basin. Results show that the daily gas production rate increases with the increase of gas-bearing index，desorption efficiency index of CBM and gas-water production efficiency index，however the correlations is not obvious. The daily gas production rate can be higher than 800 m3/d when the gas-bearing index is higher than 100 m·m3/t，the desorption efficiency in? dex of CBM is higher than 0.04（MPa·d）-1，or the gas-water production efficiency index is higher than 1 mD·MPa. The gas-production capacity index is the product of the gas-bearing index，desorption efficiency index of CBM and the gas-water production efficiency index，and it can effectively characterize the production capacity of CBM reservoir. A higher gasproduction capacity index results in a higher daily gas production rate. When the gas-production capacity indexes are higher than 0.3 and 10 mD·m·m3（/ t·d），the daily gas production rates are higher than 800 and 1 500 m3/d，respectively.

Abstract:Proppant slurry and the clean fluid are alternately pumped through pulses during channel fracturing to form a discontinuous placement of non-uniform support structures in the artificial fractures，and high-speed channels of fluid flowing could be formed in the fractures. However，the understanding of the deformation law of the proppant pillar under the formation closure pressure is unclear，resulting in an indefinite understanding of the variation rule of the fracture width，and therefore it is difficult to accurately calculate the flow conductivity of the fracture with proppant. According to the results of large-scale visualized plate proppant migration and placement experiment，placement pattern and size of the proppant pillar were analyzed，and the proppant pillars were divided into three types. The compression deformation process of the proppant pillars was simulated，and the thickness variation law and Young’s modulus of the proppant pillars under different closure pressure were obtained. The proppant pillar was dispersed into particles with actual mass and volume by the smoothed-particle hydrodynamics（SPH）. The formations are dispersed by finite element method，and their contact with the proppant pillar was calculated based on the coupling contact algorithm. Based on the size of proppant pillar extracted by plate experiment，three types of formation fracture-proppant pillar contact models were proposed. Deformed state，normal stress and height of the proppant pillar under different formation closure pressure and Young’s modulus were obtained to study the deformation law of proppant pillar. Finally，the fracture-proppant pillar flow model was proposed to study the pressure and velocity field under different construction parameters by CFD.

Abstract:An optimized high-energy gas fracturing technology was proposed to solve the difficulty on the stimulation of the deep tight gas reservoirs in the East China Sea. Temperature-resistant potassium perchlorate was preferred as the solid oxidant and temperature-resistant epoxy resin was used as the polymer binder. Addition with the use of high temperature-resistant rubber，sensitive agent，curing agent and other materials，the high temperature-resistant propellant was made by using a slurry casting process. The propellant could withstand a high temperature about 200 ℃ for 48 hours. According to the non-Darcy gas flow productivity formula and the multi-crack model after high-energy gas fracturing，the gas well productivity and production-increasing ratio model after the fracturing were derived. The correlation between the gas well productivity and fracturing parameters was analyzed. Fracturing mode with both built-in and sleeve-type propellant were optimized for different propellant parameters. The“TCP-HEGF-APR test”integration process technology has been formed innovatively. It greatly saves 50% working time，reduces reservoir damage and improves the safety of the downhole work with string tools.

Abstract:Multistage fracturing of horizontal well technique is applied to develop shale gas reservoir economically and effectively，during which a complex fracture network is formed in the formation. Therefore，it is crucial to quantitatively describe the complex fracture network to achieve an accurate prediction of gas well productivity. In order to analyze early flowback water production data and to get reservoir stimulation information，a mathematic percolation model for water phase was proposed at the constant production stage of gas wells on the hypothesis of both radical flow and linear flow in single fracture considering the influence of gas flow from matrix to fracture on water production. Combined with material balance equation，the bottom hole pressure was obtained，and according to the Duhamel’s principle，the percolation model could be extended to the blowing off stage with a variable production rate. Analysis indicates that when the internal depletion flow appears in the whole fracture system，the relation curve between normalized water rate and material balance time in the loglog coordinate is a straight line with a slope of -1. Characteristic line diagnosis could be used to calculate the effective fracture volume and fracture shape parameters. The methods is verified by numerical simulation，and the effective fracture volume is calculated combined with field cases. Results show that the flowback data collected in the blowing off stage cannot be neglected，otherwise the effective fracture volume is relatively smaller. The proposed method provides the technical support for the evaluation of fracturing performance of shale gas wells with the use of flowback data.

Abstract:It is difficult to obtain profitable production without the application of hydraulic fracturing in tight glutenites because of their ultra-low permeability.Profitable exploitation of glutenites requires a clear understanding of the hydraulic fracture propagation law in these reservoirs. Considering the heterogeneity of sandstone or gravel and the heterogeneity between sandstone and gravels，a numerical method that integrates the digital image processing technique into a numerical software named rock failure process analysis（RFPA）was proposed.Based on the method，two-dimensional simulation results of the fracturing in the tight glutenites indicate that hydraulic fractures can penetrate or deflect along the gravels depending on the conditions of stress differences and gravel strengths. Three-dimensional simulations considering gravel distribution orientation，gravel size and axial ratio reveal that the hydraulic fractures can penetrate gravels，resulting in a bypass fracture which is difficult to be observed in regular lab experiments，or deflect along the gravel which is similar to that observed in two-dimensional simulations. Main propagation modes under various gravel distribution orientation，size and axial ratio are as follows：①penetrate gravels directly；②deflect along the gravels；③bypass the gravels；④combination of①and②，or②and③.