Abstract:The relationship between formation water type and fillings material was established based on the chemical interaction between the fluid and the rock，which is helpful for accurate prediction of favorable reservoir development. Starting with the analysis of the relationship between the formation water property and the diagenetic mineral，the sedimentary microfacies and diagenetic facies developed in the lower Es3 in Jiangjiadian-Wawu area were analyzed comprehensively using microscopic analysis techniques. The results show that water distributary channel，underwater distributary channel，mouth bar and front sheet sand develop mainly in the target formation of the study area. Three types of formation water assemblages, CaCl2 type, CaCl2-NaHCO3 type and NaHCO3-Na2SO4 type, were identified, and they mainly develop in areas of the formation water block zone, the transition zone and the stagnation zone, repecitvely. The specific fluid-rock chemical interaction in the study area was determined by rock mineral difference and formation water properties，which has obvious characteristics of A stage in the middle diagenesis process and is controlled by sedimentary microfacies and diagenetic facies.Five types of diagenetic facies were identified and named as weak-compacted clay-filled and ferrodolomite-cemented facies，moderate-compacted clay-filled and carbonate-cemented facies，trong-compacted carbonate-cemented facies，strong-compacted clay-filled facies，strong-compacted quartz and feldspar-corroded facies. Different diagenetic facies have different diagenetic effects，which determines the way and the characteristics of reservoir dilatation and densification.The characteristics of reservoir development controlled by different sedimentary microfacies and diagenetic facies were evaluated by classification through superposition of diagenetic facies，sedimentary microfacies and isopach charts of sand bodies.

Abstract:Based on capillary pressure curve and experimental measurement data of porosity and permeability of 82 carbonate rocks of Zahnanor oilfield in Caspian Seashore Basin，Kazakhstan，comparison analysis of permeability prediction accuracy of carbonate reservoir was made through comparing and analyzing Swanson model，Capillary-Parachor model，Winland model，Pittman model，Nelson model and the δ function model. The results show that the calculation accuracy of the six permeability prediction models is poor for permeability prediction of complicated pore structure carbonate reservoir. But the effect of Swanson model is better than those of the other five models. Further analysis on the applicability of permeability prediction of carbonate reservoir based on Swanson model suggestes that the Swanson model cannot reflect the influences of microfracture and complex pore throat distribution on permeability. For carbonate rock sample，the pore throat，the distribution of which is characterized by multimodal feature，contributes to reservoir permeability，and there is no dominant pore throat size in the core sample. On the contrary，the Swanson model believes that the pore throat radius corresponding to the inflexion point of capillary pressure curve is the dominant pore throat size of core sample. And the Swanson model ignores the influence of small pore throat on permeability of rock sample which has a bimodal pore throat distribution. Therefore，the error of permeability calculated by Swanson model is obvious. Based on Swanson model，we put forward an improved permeability prediction model considering the influence of pore structure parameters such as porosity，skewness and sorting coefficient. It is found that the permeability prediction accuracy of the improved permeability prediction model for complex pore structure carbonate reservoir is obviously enhanced through comparing it with the Swanson model.

Abstract:Fault activities has a profound influence on the formation and evolution of rift basin and hydrocarbon migration and accumulation. Cenozoic fault activity in Suning area of Raoyang sag，Bohai Bay Basin was analyzed using 3D seismic data and well drilling and logging data，and its control on hydrocarbon migration and accumulation was discussed. The results show that Cenozoic fault activities in Suning area are obviously periodic and can be subdivided into several stages. Paleogene fault activities happened at E1k-E2s4，E2s3-E2s2 and E2s1-E3d three periods，the strength of which were from weak to strong generally，and the two most intense fault activities happened at E2s3-E2s2 and E2s1-E3d periods in the study area.Since Neogene，the faults in Suning area moved weakly only at the early stage of N2m. Furthermore，the results show that Cenozoic fault activities in Suning area control hydrocarbon migration and accumulation. It is indicated by the facts that two sets of high-quality hydrocarbon source rocks deposited at the periods of the two most intense Paleogene fault activities and their strong extension effects control the formation of hydrocarbon-rich sags，and the evolution of fault system controls the development and formation of buried-hill traps，and furthermore，affects the evolution of sedimentary facies and distribution of sand bodies. As a result，two hydrocarbon reservoiring modes were proposed. In one mode，the hydrocarbon was generated at Cenozoic and migrated laterally along faults and unconformity，and finally accumulated at Paleogene. In the other mode，the hydrocarbon was generated and accumulated both at Cenozoic with multi sources and multi-phase charging.

Abstract:Tectonic evolution is complicated and its effect on hydrocarbon accumulation is unclear for inner buried hills in Yihezhuang area of Jiyang depression，which is restricting oil and gas exploration in this area. To solve this problem，tectonic evolution characteristics of the inner buried hills was analyzed in Yihezhuang area based on data of seismic，logging，lithology and test，by which the effect of tectonic evolution on hydrocarbon accumulation was evaluated. The result shows that buried hills in Yihezhuang area evolved as following：compressional uplift in Indo-China movement，compression in phase Ⅰ of the Yanshanian movement，extensional subsidence in phase Ⅱ of the Yanshanian movement，compressional uplift in phase Ⅲ of the Yanshanian movement，and again extensional subsidence in Himalayan movement. Fault Yigu991 is a typical contemporaneous fault of inner buried hills in the researching area，and its fault activity rate verifies the tectonic evolution process of the buried hills. The fault of inner buried hills experienced multiple thrust and negative inversion stages under the influence of tectonic evolution that was characterized by many different stress properties. Multi-period tectonic evolution process of inner buried hills is beneficial to the formation of favorable reservoir and effective petroleum migration pathways，and multi-period tectonic evolution，which is well-matched with interior barriers，is beneficial to the formation of favorable reservoir-cap combinations and multiple trap types. The researching result guides oil and gas exploration of inner buried hills in researching area powerfully. With the guidance of tectonic evolution analysis，effective petroleum migration pathways prediction and favorable traps were described，the inner buried hill reservoir such as Yigu72 and Yigu65 were found successfully.

Abstract:Through comprehensive study on the seismic data，well logging data，sedimentary facies，paleogeomorphology analysis，the paleo ravine and slope-break zones of the mid-Miocene in Qiongdongnan basin were identified，and the developmental feature，distribution rule and control over sedimentary of the paleo ravine-slope break zones were emphatically analyzed. The hydrocarbon reservoir forming conditions and distribution regularity of the lithologic reservoirs developed under the environments were discussed. The results show that there are three types of paleo ravine，including“V”shape，“U”shape and dish-like shape，and“V”or“U”ravine generally developed in Ledong sag and Lingshui sag，while the dish-like ravine developed in Baodao sag. Three types of slope-break zones developed，such as depositional slope-break zone，fault slope-break zone and flexure slope-break zone with certain distribution regularity. The depositional slopebreak zone mainly developed in Ledong sag and Lingshui sag；the fault slope-break zone developed in Lingshui sag and Songnan sag；and the flexure slope-break zone developed in Baodao sag. Different slope-break zone has different influence on sedimentary.Submarine fans with rich sand developed in Ledong sag and Lingshui sag and are the main reservoir in the study area，which were controlled by depositional slope-break zone with strong hydrodynamic environment. They developed widely with characteristics of coarse grain and good physical property. Submarine fans in Lingshui sag were controlled by fault slope-break zone to some extent，which developed at the downthrown of fault named lobate complex fanbodies. Submarine fans in Baodao sag with bad physical property were controlled by flexure slope-break zone where the hydrodynamic power was weak，and thus have fine grains. Comprehensive analysis shows that some zones in Ledong sag and Lingshui sag near the slope-break zones are favorable to form lithologic reservoirs，and should be the future exploration targets in deep waterarea.

Abstract:During the early stage of evaluation of the gas field development with less well data，the established sedimentary facies model has great uncertainty only based on well data information，which is difficult to meet the accuracy requirements of geological research. Thus it is becoming more and more important to be constrained by the multi-seismic attributes for sedimentary facies modeling. Firstly under the model of Bayes，the local prior probability distributions was built，and then the probability was updated into the posterior distributions with the neighboring well data and seismic attributes data. During the updating，Markov assumption could be used to solve the problem of instability of cross matrix for different variables，and at last the sedimentary facies could be modeled through random sampling from posterior distributions of modeling points. Taking the example of the Su10 area in the north of Sulige gas field，the relationship between seismic attributes and sedimentary facies was analyzed firstly and four types of seismic attributes were chosen including RMS amplitude，average instantaneous frequency，effective bandwidth and attenuation. Considering the problem encountered in the computation of multi-variable cross-covariance，the fusion of multi-seismic attributes was calculated to obtain their fusion probability based on Markov-Bayes model，by which a sedimentary facies model could be built. The result demonstrates that simulation result keeps an over 80 percent agreement with a sedimentary facies model drawn in hand. The prediction error is considered to be within 1% through the analysis of cross-validation.

Abstract:With the analysis of the distribution，lithology，color and mineral features under SEM of the dolomite，the origin of the dolomite in Block1 in Yemen and the impact of dolomitization on oil and gas accumulation were studied. The thickness of dolomite in Block1 is large but it distributes in a very limited area near Well Imad-1. The crystals of dolomite look like sugar with main features of saddle dolomite. Only the traces of shell fossils are observed. There is no sphere，irregular thorns and rhombic shapes observed in dolomite cores and thin sections. And the dolomite is grey-dark grey，the dark color of which indicates that the dolomite contains high contents of ferrum and manganese. All these feature points to hydrothermal genesis of the dolomite of Block1 in Yemen. It is inferred that hydrothermal fluid comes mainly from the deep area with abundant Mg2+ ions. It flowed upward to the upper strata through the faults or disconformity and exchange between Ca2+ from the limestone and anhydrite and Mg2+ from the hydrothermal fluid occurred. Finally，some thick dolomite rocks developed near the faults（or disconformity）with limited lateral distribution. The formation of dolomite can increase the pore spaces of the reservoir，but it can damage the cap rock and preservation condition. Considering the influence of faults as well，it is believed the southeast area in Block1 has lower potential of oil and gas accumulation，but the Magraf belt in northwest area is suggested as future exploration target in Block1.

Abstract:At present mixosedimentite reservoir is the most important targets in the oil and gas exploration and development of the Shahejie Formation in the Shijiutuo uplift，Bohai Bay Basin. However，there are few studies on the sedimentary characteristics and the reservoir features of the mixosedimentite. Thus systematic research on the mixosedimentite reservoir is needed. Based on the data of coring，casting thin sections，logging and testing，etc.，it is concluded that the mixosedimentite in the eastern margin of Shijiutuo uplift is the mixture of the terrigenous clastic and carbonate components. And the lithology mainly includes fine sandstone containing intraclast，medium-fine sandstone containing bioclasts，conglomerate containing bioclasts，sandy bioclasts dolomite，sandy micrite dolomite containing bioclasts-intraclast and sandy bioclasts dolomite. According to the analysis of the reservoir physical properties and the result of the diagenetic evolution，the physical properties of the mixed bioclastic beach developed in the semi-closed or closed lake-bay is the best while that of bioclastic sandy beach and the bioclastic gravelly beach developed in the fan delta front is second. The main factors controlling the reservoir physical properties are lithofacies，sedimentary facies，compaction，cementation and dissolution，among which lithofacies and sedimentary facies are the precondition for the formation of high quality reservoir. Compaction plays a less important role on physical properties of reservoirs due to its suppression. In contrast，the late diagenesis，such as cementation and dissolution，are more important for improving reservoir physical properties.

Abstract:Fluid saturated with CO2 is common acid one. Carbonate mineral may be solved in the acid condition and secondary intergranular pores may be produced，which is the important origin of secondary pores. Experimental installation for diagenetic simulation was designed. Two ways of fast heating and slow heating were adopted with a temperature range from 50 ℃ to 120 ℃. Four water-rock experiments and one hydrothermal experiment were made to research the dissolution of calcite under different heating rates and the formation mechanism of the secondary pores of the carbonate. At the beginning and end of the experiments，all the calcites were weighed，and the dissolution topography of the calcite for observation were observed under the optical microscope and scanning electron microscope. It shows that dissolution rate of the calcite is fast and the dissolution was controlled by temperature and CO2 partial pressure（ pco2）. The fall of the temperature and rising of pco2 is beneficial to the dissolution of calcite. The faster the temperature rose，the more the calcite would be dissolved. In the sealed system，after the calcite was dissolved for quite a time，the dissolution of the calcite will be inhibited by the high concentration of ion. Along with the dissolution of the calcite，the dissolution topography of the calcite experienced 4 stages：dissolution micropore，dissolution belt，dissolution sawtooth and dissolution crystalline cone.

Abstract:The purpose of history matching of reservoir numerical simulation is to verify and modify the numerical simulation model，so as to improve the reliability of numerical simulation model and the prediction accuracy of oilfield development indexes. At present the common methods of history matching lack systematicness and normativity，which introduces a certain randomness and arbitrary to the modification of the numerical simulation model. A set of systematic analysis method of history matching was put forward based on numerical simulation model building and initialization inspection. Starting with the analysis of matching phenomenon，matching contradictions between dynamic and static data can be divided into five types and three key matching points were also pointed out based on matching curve shape. According to the different types of matching contradictions，influence factors on matching indexes were analyzed and the possible causes of matching contradiction were listed. Combined with the dynamic and static data and understanding of the actual block，the uncertainty of the numerical simulation model was analyzed. Exclusive method was used to quickly determine the specific reasons for matching contradictions. The numerical simulation model was repeatedly modified until the accuracy of history matching was attained. The case showed that the number of times of the numerical simulation is greatly reduced，and the efficiency and accuracy of the history matching are improved using the method. The practicability and validity of the method are proved.

Abstract:There is a big difference in seepage law between the traditional well group and combined well group of single horizontal well and multi vertical wells for SAGD heavy oil recovery. The horizontal well can convert the injection-producer relation between the original vertical wells from a parallel plane one to a three-dimensional region one. Research on three-dimensional seepage mathematical model is based on potential theory. The seepage process of horizontal well was regarded as three-dimensional line sink and the ellipse potentiometric surface with the focus of the two ends of the perforation interval in the horizontal well was derived；the vertical wells were regarded as multiple planar point sources through longitudinal stacking and the cylindrical potentiometric surface with vertical well as the center line was derived；the mathematical model of the seepage pressure field and the pressure gradient field during the process of displacement in the composite well group was derived based on the coupling of the above results using potential superposition principle. Producing range of three-dimensional reservoir and the effect boundary of gravity discharge were determined. Effect of gravity on SAGD development effect，pressure field and pressure gradient field was analyzed. The results show that the gravity may enlarge pressure gradient field at far-wellbore zone or area with low pressure gradient produced by source and sink，which promotes the heated fluid in the oil reservoir to discharge to the horizontal wells.

Abstract:In order to understand the percolation mechanism and development regulation in low-permeability buried-hill fractured heavy oil reservoir，similarity criteria of physical simulation on water flooding and hot water flooding in the fractured reservoirs was established by using similarity theory and flow theory. Taking a low-permeability buried-hill fractured heavy oil reservoir in Bohai Sea as an example，a large scale physical model（1 m×1 m×0.5 m），as analogy of the objective reservoir，was designed to simulate the water flooding experiment in different well patterns and development modes. Analysis results on oil production，water production and water-oil saturation in experiment show that：the stereoscopic horizontal well pattern can give full play to the function of oil-water gravitational differentiation and reduce the rising rate of water cut in the buried-hill reservoir. The staggered well pattern can increase the sweep efficiency of the injected water by increasing the injector-producer distance. Effect of the hot water flooding becomes worse as the injector-producer distance increases.The addition of surfactants into the injected water can increase the oil displacement efficiency in the fracture and lower the imbibition effect and matrix contribution rate.

Abstract:Oil reservoirs with strong edge/bottom water often have complex oil-water relationship and no uniform oil-water contact，and the coning of edge/bottom water would severely influence oil well production and its stability. In the early production stage，it is difficult to know the reservoir only according to limited well drilling data. However，the key to develop this kind of reservoirs is to obtain reservoir parameters，aquifer volume，water invasion index and water influx. Based on the advanced Blasingame production decline analysis method，pseudo-steady state water invasion model was applied to deriving the reservoir parameter evaluation method for the reservoirs with pseudo-steady state water invasion. The water influx，aquifer volume，water invasion index，dynamic reserves and reservoir parameters were calculated quantitatively. This method firstly divides well production history into three periods：no water invasion period，early water invasion period and middle-late water invasion period. Then the reservoir parameters and well dynamic reserves can be evaluated by matching well production data of no water invasion period with the typical advanced Blasingame production decline curve，and the aquifer volume，water invasion index and water influx can be quantitatively evaluated by matching well production data of early water invasion period. Finally，the numerical simulation result of the established conceptual model verifies that the method is practicable. The error of the dynamic reserves is -3.31%，the error of the permeability is 2.60% and that of the aquifer volume is -2.5%. The matched results of the new method have acceptable errors，which cannot influence the determination of development mode greatly.

Abstract:Response surface methodology is an optimization method which selects main controlling factors by PB experiment and determines the optimization program based on the method of steepest ascent. On this basis，an optimization method of injection-production parameters for SP flooding was established. This method overcomes the disadvantages of some traditional optimization methods. So this method has the advantage of obtaining the optimization design in a fast and precise way. Ng41-51 submember of the 7th block of Gudong oilfield was selected as the typical unit of the research for the SP flooding. Then main controlling factors of the effect of the SP flooding were selected by PB experiment after the history matching.Next，the optimized value and effect of these main controlling factors on development results were determined according to BBD experiment. The optimized value of the main controlling factors was used as the production factors in the calculation using Eclipse simulation software. The calculated value of enhanced oil production per ton polymer is 21.894 m3/t with a relative error of 2.01% compared with the result of response surface methodology. The well agreement indicates the effectiveness of this method. The optimization results of the orthogonal design were compared with that of the response surface methodology. It shows that the best value of enhanced oil production per ton polymer was improved by 5.9% using the response surface methodology，which highlighted the superiority of this method.

Abstract:Tight oil and gas have become the key point of research and development in the field of unconventional oil and gas. As an important part of tight oil and gas seepage mechanism，the influence of imbibition can effectively improve the recovery of oil and gas. However，there are few researches on it. The imbibition experiment was conducted under different conditions on matrix cores of the domestic typical tight oil and gas reservoir. The phenomenon and results in this experiment were analyzed. A new seepage mechanism of the matrix cores in the tight oil and gas reservoir was purposed，called layer imbibition theory，which means the imbibition starts from the surface of the cores to the inner of the cores step by step.The imbibition efficiency formula according to the quality method was revised and the accurate results of the indoor imbibition experiment were calculated，and the results were calibrated to the actual formation scale. The results show that the oil/water imbibition efficiency of the matrix cores in the tight oil and gas reservoirs is 12%-18% under reservoir condition and imbibition speed is estimated in the order of magnitude of 1×10-4 cm/min. It is necessary to use the imbibition method together with other displacement methods for the tight oil and gas reservoirs so as to improve the final recovery of the tight oil and gas.

Abstract:Chengdao oilfield has entered middle-high water cut stage. Due to the influence of strong reservoir heterogeneity，uneven waterline rush，serious interference of production in multi-well groups and the imbalanced displacement of injected water in the underground directly affect the overall development effect of the reservoir. Therefore，a vector optimization method for reasonable liquid production and water injection rate was proposed. Concept of displacement breakthrough coefficient was established，and equilibrium displacement limit was determined to be 3. The actual reservoir displacement was divided into 4 modes. Reasonable fluid production and water injection rate of oil-and-water wells under different displacement modes was determined，and thus the goal of balanced reservoir displacement could be achieved. This method was applied to field liquid increase test in seven well groups of Chengbei 11N well block. By the end of December 2015，incremental cumulative oil was 2.7×104 t，and recovery rate was increased by 5% in the evaluation period（15 a）.

Abstract:The effective connectivity between the producer and injector in start-up period of SAGD has significant effect on production period. Field practice shows that the preheating time of conventional steam circulation is long while steam consumption and heat loss are large. In order to overcome these problems，evaluation experimental apparatus for solvent injection and soak was designed to evaluate the effect of viscosity reduction of xylene through sand pack soak by xylene injection at various flow rates. The results show that the viscosity of heavy oil decreased significantly with the increasing of xylene solvent content without asphaltene precipitation production，and the mobility of oil was enhanced. When the injected solvent content reaches a certain value，viscosity is no longer reduced. The oil phase permeability increases with the increasing of flow rate of the solvent，but the range of increase gradually decreases. After solvent soaking with pressure，the solvent spreads around to improve the sweep area and expand the flowing channel，and the oil permeability will be increased further. The application in a certain block of A oilfield in Xinjiang shows that circulation and preheating time in the solvent soaked well group significantly decreases by about 60 d and the injected steam volume decreases by about 4 000 m3. The connectivity degree between the producer and injector is about 85% when ES-SAGD production begins. Numerical simulation and pilot test present that solvent injection of ES-SAGD in start-up period can shorten the preheating time of steam circulation，reduce the injection steam volume，make even preheating between producer and injector and improve the preheating efficiency and economic benefit.

Abstract:The fracture initiation and propagation of hydraulic fracturing are important to post-fracturing performance of tight oil and gas reservoirs. Based on uniaxial compression experiment results of rock specimens taken from tight sandstone reservoir at 3 200 meters depth in certain block of Shengli oilfield，rock mechanics parameters used in the numerical simulation of uniaxial compression experiment were calibrated，and the effect of brittleness index and residual stress on hydraulic fracture propagation was investigated by using numerical simulation software RFPA2D. The results show that higher brittleness index is more favorable for hydraulic fracturing propagation，and hydraulic fracture with larger width and smaller initial stress can lead to larger area of effective complex fracture network and better hydraulic fracturing effects. When the residual stress is lower，the degree of development of hydraulic fracture is higher with wider fracture width and smaller initial stress and the effects of hydraulic fracturing are better.

Abstract:Micro-emulsion has been used in EOR as oilfield agent for decades，but not in drilling fluid. Wellbore instability and high friction have been encountered frequently during the drilling process in horizontal and directional sections. Common agents used in drilling fluid cannot meet the demands of plugging and lubrication at the same time. A nonionic microemulsion WR-Ⅰwas developed based on compound surfactants of Span-80 and Tween-80 aided with co-surfactant of nbutanol.The effect of the nonionic micro-emulsion WR-Ⅰon the performance of drilling fluid was investigated，focusing on its plugging and lubricating properties. The results show that the nonionic micro-emulsion WR-Ⅰhas good performance including super-low interfacial tention of 0.005 mN/m and median size of 75 nm. It has little influence on the rheology of the drilling fluid and can lead to a small reduction in filtration loss. It can stabilize the wellbore of the shale section by quick adsorption and effective plugging with a blocking ratio of 95%. It has good lubricating property with an extreme pressure lubrication coefficient of 0.051 and a sticking coefficient of 0.138，which can effectively decrease the friction between drilling tools and wellbore as well as drilling cuttings.