After analysing the basic petroleum geolegic conditions of Junggar, Tarim, sichuan Basin and their major hydrocarbon bearing areas, we prove that the formation and its development of a hydrocarbon bearing basin is closely related to the regional tectonics and its evolution. Within a basin, the existance of structural elements, sources, reservoirs, seals and sedimentary conditions et al., follows a certain order each. Thus, the regularity of oil and gas pools' distribution is brought out from foreland to craton basin. The basin is constituted as an organic integrated entity provided with a system of oil pool composition. Under this circumstance, the hydrocarbon bearing basin shoud be treated as a whole one in explorating affairs, and the synthetic three-dimensional alternated exploration is needed emergently.

Multiple oil and gas bearing layer of a big time span occur in Bohai Bay Basin, and the major assemblage is different from one part to another, so it is of great importance for exploration practice to acquire a deep understanding of the distribution of oil and gas series. On the basis of comprehensive study of tectonic evolution and sequence stratigraphy, this paper analyses the regional distribution regularity and controlling factors of oil and gas bearing series in the basin, and gets four conclusions. (a)The primary controlling factor accounting for the forming of multiple oil and gas series is the tectonic evolution which determines the overall vertical oil and gas distribution features. Sags with similar tectonic evolution history have the same major oil and gas bearing formation assemblage that generally contribute about 70%~80% of proven reserves of the whole sag. (b) The uplifts surrounding the basin are major sediment source areas. The spatial matching relations of a sag and the uplifts has significant influence on the composition of sequences and the development of source rock-reservoir-cap rocks, thus controlling the vertical oil and gas distribution. (c) An evident strike-slip displacement may enhance the sealing ability of faults and enable oil and gas to accumulate in lower horizons. (d) For sags of high reserve abundance, they have large time span of oil and gas series; for those of low reserve abundance, the major reservoirs are near the mature source rock body.

According to the degree of concealment, the main origin type and the profile form of hydrocarbon traps, a new classification for subtle traps has been made on the basis of predecessors work. It includes not only stratigraphic and lithologic reservoirs, but also paleo-structure trap reservoirs, syncline reservoirs and low permeability reservoirs being susceptible to damage, etc.. It is helpful for petroleum explorationist to expand research fields and to apply different methods by different types of subtle traps in hydrocarbon exploration.

A complete terrigenous sequence in fault-depreesed lacustrine basin can be divided into four system tract: Lowstand System Tract (LST), Trangressive System Tract (TST), Highstand System Tract (HST) and Regressive System Tract (RST), which has typical geometrical configuration and respectively consists of lowstand-aggradation regression, highstand-aggradation and progradation. The four-divided system tracts in a complete terrigeous sequence were sedimentational response to accommodation change resulting from a sedimentary baselevel cyclicity. The principle to divide system tracts for a complete terrigeous sequence in fault-depressed lacustrine basin is that the lacustrine thick-layer mudstone represents HST and boundary between RST and TST, and that the above first flooding surface (f.f.s) is TST and below f.f.s is LST. From bottom to top, a complete terrigeous sequence in fault-depressed lacustrine basin consists of the following sequence units in turn: Sequence Boundary (SB)→Lowstand System Tract (no coast-onlap)→Trangressive System Tract (distinct coast-onlap)→Highstand System Tract being composed aggradational lacustrine mudstone with low sedimentation rate→Regressive System Tract (distinct coast-dropback)→Sequence Boundary (SB).

Sedimentary fabric analysis shows that middle member Ⅲ of Shahejie Formation (S ₃ ^m) is mainly composed of normal deltafront sediments in this study areas. Magnetic anisotropy measurements were carried out on samples from rotary drilling cores, and the results were used to calculate the direction of paleo-current oriented by magnetic polarity. The distribution of paleo-current, coinciding with the prograding direction of the Dongying Delta from the southeast to northwest, distinctly manifests that in the study areas, X, Y and Z blocks in Dongying depression are directly controlled by Dongying Delta during the sedimentary epoch of S ₃ ^m. The comprehensive analysis on the source and the sedimentary characteristics proves that area of Dongying Delta should be expanded. Thus, there will be widening area in the Dongying Delta inferred to be further prospect of lithological oil pool exploration. The method shown in this paper could be a new way to analyze the paleocurrent in paleo-limnological delta and will provide new scientific data to serve the petroleum exploration.

Evaluation and prediction on hydrocarbon generation potentials of various sedimentary organic facies of carboniferous source rocks in Tarim Basin were carried out in this paper by fuzzy mathematics, a new method for quantitative petroleum resources evaluation. This method is different from the methods of basin modeling trend surface analysis, kerogen degradation dynamics et al. With this method, geological variables are taken as fuzzy variables and calculation is carried out based on the theory of fuzzy mathematics. In this paper, parameters of thickness, organic matter abundance, organic matter type, organic matter maturation and sedimentary organic facies of Carboniferous source rocks were taken as fuzzy variables to calculate hydrocarbon generation potential of source rocks in various sedimentary organic facies. The calculation results indicate that hydrocarbon generation potential of open platform and semi-restricated platform sedimentary organic facies are best, which are followed by evaporated platform and open lagoon sedimentary organic facies. From the calculation results, the authors put forward that Carboniferous source rocks are well-developed in the western Tarim and possible big oil and gas pools can be found which may be self-generated, self-reservored and self-capped under suitable structures. Meanwhile, we should pay attention to the hydrocarbon generation of Carboniferous argillaceous source rocks in the eastern Tarim.

Niger Delta Basin is a Meso-Cenozoic sedimentary basin and it is located along the triple junction area of African plate and Atlantic plate. During geological history, the basin underwent an evolution of uplifting, faulting and fault-tilting. The basin is characterized by multiple oil pool types and many oil-bearing layers. The massive oil pools as roll-over anticline are dominated in the shallow horizons. Faulted block, faulted-nose, lithostratigraphic and turbine pools are dominated in the deep. Macro structures control the primary oil accumulation and distribution in the Basin. Secondary fault zones, turbine and sand bodies of different faces belts and foot wall block structures play an important role in hydrocarbon reaccumulation and redistribution, which are the new area with high potential.

Phenols are isolated from crude oils using C ₁₈ solid chromatographic column. The content of the compounds in oils are much low, and the general characteristcs of the compounds are similar (such as the types of phenols), although there are some difference in relative distribution between marine and terrestrial oils. For example, there are more alkylphenols with longer alkyl chain in terrestrial oils than in the marine oils. Compared with nitrogenous compounds,phenols display similar oil migration effects during migration, but the factors that control their distribution are different. Original source type, oil migration, maturity, and so on, may be all have effects on alkylphenols.

The relative permeability curve of ASP/Oil system was obtained by measuring that of AS/Oil system using steady-state method after polymer retention. The effect of polymer retention and interfacial tension on the relative permeability curve was investigated. The results shows that polymer mainly increase the irreducible water saturation while decreasing the height of relative permeability curves for both water and oil phases; alkali and surfactant mainly decrease the residual oil saturation while increasing the height of relative permeability curve for water phase. The experiments indicated the relations between polymer retention and irreducible water saturation, end-point relative permeability reductions for water and oil phases, and that between interfacial tension and residual oil saturation, end-point relative permeability for water phase.

Multimodel experiment simulating reservoir water flooding and made up of several different models in physical property is recommended to study the effect of heterogeneity of a reservoir in flooding process. A new parameter-the minimum permeability of water drawing layer, K _wmin of multilayer-injected interval was measured by multimodel experiment and the relations among K _wmin and maximum permeability of multilayer-injected interval and water flooding pressure gradient were determined by which the K _wmin of other wells of the reservoir can be estimated. It is found that the K _wmin is very helpful to predict the water-flooding effect of a reservoir and the distribution of residual oil. The satisfactory results from application of K _wmin presented in this paper were obtained in Sanjianfang reservoirs, Shanshan Oilfield. It is obviously that further study will lead to extensive application of this new parameter.

At present the Vogel's study methodology, in which an inflow performance relationship (IPR) curve for a solution-gas-drive well is generated at a constant recovery factor, the dimensionless IPR curve can then be obtained, which has been applied to prepare IPRs of solution-gas-drive horizontal wells based on numerical reservoir simulation. The research in this paper discovered that the production processes have a significant influence on performance of a solution-gas-drive reservoir, namely, the average reservoir pressures are not equal when the productions with different flowing bottom-hole pressures reach the same recovery factor. Therefore, there is a drawback in current methodlology of preparing IPR curve based on the numerical simulation calculations. An improved methodology is proposed that the IPR curve of a horizontal well producing from a solution-gas-drive reservoir is firstly prepared at a constant average reservoir pressure, the dimensionless IPR curve is then generated. Based on the new methodology, 3-D flow calculations for a wide variety of solution-gas-drive reservoir models are made. How the concavity of dimensionless IPR curves varies with the decrease in the average reservoir pressure is found. Then a new equation is presented to fit the dimensionless IPR curves of solution-gas-drive horizontal wells.

A new initiation mechanism is proposed for gas hydrate formation from liquid water. Based on this mechanism, a new thermodynamic hydrate model has been developed and extended to the electrolyte-containing system by incorporating with modified Patel-Teja equation. A number of test results indicate that the new model is superior to the traditional van der Waals-Platteeuw typed ones and adequater for prediction of the hydrate formation conditions for natural gas, gas condensate or crude oil. It has been also shown that the new model is applicable to the system containing brine inhibitor.

Laboratory test of rheological property of polymer solution shows that polymer solution rheological property is inline with power-law mode. According to non-Newtonian fluid mechanics theory and mathematical method, conbined with plunger moving property, the hypothesize fluid is imcompressive, hydraulic radius of flow of liquid in crevice is very little, and it is laminar flow, the flow is treated fixed continuous flow at every instant position of plunger, equation of motion and boundary condition were set up in condition of concentric and eccentric of pump barrel and plunger. Dimensionless coordinate, dimensionless velocity, crevice height of plunger and eccentric pump barrel matched were introduced, and analytical solution were given. Special case of rheological index n=1 were discussed, that velocity and flow rate equations were obtained agrees with completely crevice flow equations used both inside and outside the country. In addition, relation curves of leakage to pressure difference in condition of concentric and eccentric of pump barrel and plunger of Newtonian fluid and non-Newtonian fluid were plotted,the result is eccentric leakage bigger than concentric leakage in condition of identical other conditions provide theoretical basis for correct calculation of discharge coefficient for pumping well.

The torque and drag of the drillstring in extended reach well will increase extremely with the increase of the depth and displacement when the top string does not rotate during sliding steering drilling operation. The hole cleaning will also be impaired and the hole direction control will be very difficult. The future application of ERD will be challenged by these problems. It is recognized that the extreme extension of the extended reach well is limited when sliding steering system is applied. A schematic research using rotary steering tool to drill ERD has been done in this paper. RSDS (Rotary Steering Drilling System), a rotary steering tool, that can be telecontrolled and controlled automatically in the downhole, the working mechanism and design were studied theoretically. The rotary steering tool studied in this paper is powered and cooled by drilling fluid, it's reliable and has simple structure. RSDS will control well path accurately, reduce torque and drag remarkably and improve hole cleaning condition obviously. The drilling practices of ERD will be more reliable if RSDS is used.

In order to meet the needs of the deep well and over depth well drilling, the new turbodrill research and testing processes are introduced in detail based on experimental investigation. The design of turbine cascade blade and flow-field analysis are conducted by using numerical fluid mechanics and computer simulation techniques. The turbine cascade with high efficient and low pressure drop is developed. The operating life of the developed cascade is increased greatly because of the application of new materials as well as technology for developing thrust bearing set. Meanwhile, the turbodrill structure and its technical characteristics are introduced. Compared with the same kind of foreign products, the cascade has a lot of advantages, for example, low pressure drop, long-life, non-rubber element, and is especially suitable for deep well and over depth well drilling etc. are emphasized according to the field test results. To settle existing problems in field operation, five suggestions are proposed in order to speed up the application of the turbodrilling technique.

It is very important for the designs of well casing strings, especially for those of deep wells and super deep wells to analyze the load bearing capacity of tubes inside slips. There are many different model to deal with this problem including that of API. However, those models didn't consider the local bending stresses at tube walls due to the actions of slips to tubes. That means their analysis are applied only to the calculations of plastic load bearing capacity of tubes inside of slip. Based on shell theory, this paper presents a new model about the elastic load bearing capacity of tubes inside of slips and the calculated results shows that it is consistent with those of FEM and experiments.

In order to improve the operating life of prick valve of high reciprocating pump, the design method for the valve is studied by combining FEM and structural optimization. The method for element mesh, load calculation, boundary condition determination are presented. A model is established in which the maximum stress on the prick surface of the valve is used as an objective function and the restrain conditions are fixed by considering of the strength and dimension of the valve. A calculation example shows that, the maximum stress at the prick surface of the valve and the valve seat is effectively decreased.

Design of wellhead protector system against ice loading is an important problem in oil development in shallow waters in Liaodongwan, Bohai Gulf. To investigate the stress state of the developed protector system using the riser to directly resist ice loading, types of joint three dimension finite elements and many boundary elements are used to model the layers of steel pipes and cement or concrete to establish the FE structural model of the system. The constraint conditions of the soil deposits to the structures are modeled by finite difference method. An ice sheet of 60mm thickness in extreme conditions is supposed to act on the thickened riser. The detailed analysis of stresses and displacements of the structure shows that the maximum displacement is at the top of the structure and the maximum stress in the top round plate connecting the riser and the outermost casing, with all the displacements and stresses in the system being in the allowed ranges. It is seen that the cemented concrete layers between the casings take very active part in increasing the strength of the structure.

By using polymers having different molecular weight and cores with different pore size taken from reservoirs in Daqing Oil Field, many core floods have been performed. The behaviors of both solution and propagation in porous media, such as viscosity of polymer solution, resistance and residual resistance factor, incremental oil recovery and mechanical degradation, have been studied as a factor of molecular weight. The injectivity has been studied as a mutual factor of pore size of core and molecular weight. The results show that all those parameters in terms of viscosity of polymer solution, resistance and residual resistance factor, incremental oil recovery and mechanical degradation increase as molecular weight increases. The remaining viscosity of the polymer solution is higher though the polymer with higher molecular weight has bigger viscosity loss caused by mechanical degradation under conditions of Daqing Oil Field. The results also show that no plugging occur in a core when the mid-value of pore radius is over 5 times of the gyration-radius of molecules in the polymer solution. Field results of polymer flooding performed in similar geological and operational conditions indicate that the polymer flooding with higher molecular weight has better response and the polymer produced from producers has higher remaining viscosity and molecular weight than those with lower molecular weight.

By 1998,crude oil production of China was 1.6×10 ⁸t/a,and China was the world's fifth-largest oil-producing nation.Natural gas production of China was 223×10 ⁸m ³/a,and China was the world's eighteenth natural gas-producing nation.Towards new century,the petroleum geology of China will progress in the following five ways:(1) in the new development of non-marine facies hydrocarbon accumulations;(2) in the study of source rocks origins and composite megastructural oil and gas(regions) belts theories;(3) the study on petroleum systems in marine facies hydrocarbon accumulations of China;(4) in research on buried-hill oil and gas traps of China and(5) digital earth as an important technologies carry out petroleum geology of China in the new century.

After many years of exploratory practice in Bohai Bay Basin,breakthroughs both in practice and knowledge have been made in this inshore area(0-5m below water surface),in which the exploration level is still low.Relying on a fact that depo-center and subsidence center have migrated gradually from the basin edges toward the Bohai Bay center since the early Tertiary Paleocene,and combining with features of the known oil-gas bearing belts,the favorable position in petroleum geology and oil-gas bearing features of inshore area are discussed in this paper from a point of view of petroleum system.The inshore area is just located in the superimposed or stacked area between Es ₄-Es ₃ source rocks and Es ₁-Ed source rocks.Meanwhile,it possesses the onshore Es ₃ and Es ₁ as well as the offshore Nm and Ng regional seal rocks.Hydrocarbon-supplying period of the two sets of source rocks in long(Ed-Q).Many oil-gas bearing horizons were formed in the inshore area.Finally,proposals for further research and exploration are offered aiming at the existed favorable exploratory targets in this area.

The Bohai Bay Basin was developed in a dextral transtensional tectonic setting during the Cenozoic,therefore,strike-slip movement was one of major controlling factors on structural deformation,basin formation and hydrocarbon accumulation.Strike-slip activities along deep fractures created three zones of NNE trending,rightlateral,master wrench fault systems,two zones of NWW trending,left-lateral,master wrench fault systems,and a number of different kinds of strike-slip associated structures,such as echelon fractures and folds and rotary structures.The difference in the strike-slip displacement of faulted blocks was responsible for coexisting of extension rifting and compressive uplifting.This may be a major mechanism of that shifting of rifting and depocenter from the outer part of the basin to the central part occurred synchronously with uplifting and eroding of the outer part of the basin in the Paleogene,and one of important genetic mechanism of that the sags of the basin are strongly separated by the uplifts.Compression,folding and uplifting,induced by the strike-slip movement,controlled in different degree the formation and distribution of major hydrocarbon traps in the basin.Difference in the major oil and gas bearing series in different parts of the basin is partly related to the strength of strike-slip deformation.

There exist four large fault belts in the Qinghai-Tibet Plateau from the north to the south.They are the southern Kunlun belt,the Longmucuo-Jingshajiang belt,the Bengongcuo-Nujiang belt and the Yaluzangbu belt.According to these block boundaries,the plateau can be divided into six terraces including Lunlun,Bayankala,Qiangtang-Changdu,Gangdes and Himalaya.In each of the terranes there are many Mesozoic-Cenozoic remained basins which are overlapping basins.Based on the characteristics of the tectonic evolution and the sedimentary layers of the plateau,and referencing the plate tectonics theory,the plateau can be divided into twenty seven Mesozoic-Cenozoic remained basins.Based on their proto-types all of the basins can be classified into five categories which are interior rift basin,passive continental margin basin,fore-arc basin,inter-arc basin and back-arc basin.

The ability of caprock sealing free hydrocarbons includes two aspects:one is displacement pressure of the bottom caprock and other is absorption resistance of capillary for water in caprock.The absorption resistance has something to do with lithology,degree of lithogenesis and thickness of caprock.The smaller the grain size of caprock is,the higher the content of clay mineral is,the stronger the degree of lithogensis is and the thicker the caprock is,the stronger the absorption resistance and the sealing ability of caprock are.Based on the mechanism of low-velocity seepage of pore-fluid in caprock,the absorption resistance is equal to twice as much as ultra-pressure value of fluid in the pore of caprock.Calculated results reveal that the absorption resistance of Qingshankou formation in Sanzhao depression of Songliao Basin is approximately twice as much as the displacement pressure of the base for the caprock i.e.The real sealing ability of the caprock is approximately three times as big as the known ability in the past.The research result can be used to explain why Quaternary system caprocks with high porosity,high permeability,and ultra-low displacement pressure have sealed a great quantity organic gas in many basins in our country.

At present,deep strata is the important field of natural gas exploration.Low resolution and low signal-noise ratio are big obstacles in the way of increasing the accuracy and level of deep strata exploration.According to seismic wave transmission theory,fractal method is adopted to combine seismic data with sonic log data together.A software package was developed to recover the high frequency of seismic that has been attenuated by strata absorption.Processed seismic data show the real underground structure in detail.Substantial seismic data has been processed and analysed in Wangjiatun-Shengping area and Gulong area.It shows that this software package is effective in enhancing the resolution and increasing the signal-noise ratio of seismic data.

The petroleum system of the faulted basins in the eastern China has the characteristics of multi-levels,in accordance with the basin structure and exploration degree.The basic unit of system is proposed to have single center of oil generating depression(or sag).The basis of multiple petroleum system is the existence of active source rocks of different geological ages in the basin.It's the result of activities of faulted-blocks with mullet-phase high geothermal field in the faulted basin.The occurrence and the distribution of petroleum systems in the basin are controlled by intensity and time of faulting activity.The petroleum systems can be defined by the oil-source correlation with the biomarkers.Taken the Zhanhua sag in the Jiyang depression as an example,the formation and characteristics of the multiple petroleum system are expounded.Three series of source rocks in the basin are the third member and fourth member of Shahejie formation of Eocene and the first member of Shahejie formation of Oligocene.Each of source rocks was deposited in the specific environment and experienced different evolutional stages,finally three kinds of crudeoil are generated.Attribute and maturity of crude oil are clearly displayed in their biomarker composition.There are three kinds of source rocks and three periods of pool formation in the multiple petroleum system of Eocene and Oligocene in the Jiyang Basin.These systems have own combination of the source-reservoir-caprock,migration path and distribution.They are superposed or intercalated in the geological space and have multi-phase in the geological ages.

Because of oil and gas field numbers and accumulations having fractal relations,the paper introduced fractal method to predict undiscovered gas field numbers and accumulations in the north of Songliao Basin by dividing the sizes of the discovered gas fields into 9 categories.The truncate shifted pareto distribution method is also used to predict total undiscovered gas reserve.The caculated result shows that the reserve predicted by truncate shifted pareto distribution method comforms with the reserve predicted by fractal method very well,which proves the reliability of the fractal method.The following conclusions have been made:there are fractal relationship between the number of oil and gas fields and their sizes,and the fractal method has the good application result in the highly explored basins and zones,but there are some difficulties in newly exploring areas.

The disparity between displacement efficiency and ultimate oil recovery in Chinese waterflooded reservoirs is big.For example,average displacement efficiencies corresponding to 1.0 and 0.98 of water cut are 0.6664 and 0.5045,but average ultimate recovery is only 0.302 for Chinese waterflooded fluvial facies reservoirs.It is shown that the sedimentation types of Chinese oil- fields mostly are continental deposit,heterogeneity is serious and sweep efficiency is still low.So enhancing sweep efficiency is one of two important ways of enhancing ultimate oil recovery.By using the research method of geologic model plus numerical simulation plus reservoir engineering plus mathematical statistics,"Evaluation System for Situ and Area Sweep in Waterflooded Bedded Reservoir" has been established.According to calculated results of this "System",three major rich areas of "large scale" unswept remaining oil in waterflooded bedded sandstone reservoirs have been determined:1.the unswept remaining oil in top of waterflooded positive rhythm reservoire with high viscosity oil;2.the unswept remaining oil in side parts and corners of oil reservoirs;3.the unswept remaining owing to development of non-proportionably each substratums in a series of strata.The determining methods and its developing methods of the unswept remaining oil are now summarized.It is shown that the study of these methods is very difficult and is one of kernel technology of present oilfield development and can be called a difficult century problem of world level.The research of this paper is a little progress solving the difficult problem.

Since the deep-seated reservoir bears high pressure and high temperature,a partial or complete irreversible deformation is generated in the development process of deep-seated reservoir.The deformation apparently influences the reservoir's dynamic characteristic.Using analytical and numerical methods,flowing pressure distribution on variable boundary condition is derived from dealing with one dimension nonlinear-elastic flow mathematical model in deformed media,and compared with the results from general linear-elastic unsteady flow in porous media,and emphatically analysis flowing pressure distribution caused by the variation of permeability.The result shows that,as deformed media's elasticity increase,the formation pressure increase slowly at constant water injection rate and water injection rate increase under constant flowing bottom hole pressure.The formation pressure decrease rapidly at constant oil production and oil production decrease under constant flowing bottom hole pressure.The initial formation pressure should be retained in deformed media reservoir development in order to obtain a higher recovery.

Based on the contemporary shared memory Symmetric Multi Processing parallel machines(SMP),and the directive parallel programming platform,this paper discusses optimization and parallelization of a sparse linear equations solver package MFS for reservoir simulation software with more than one million nodes.Firstly,with the high performance characteristics of contemporary microprocessors,we organize the optimization of MFS by adjusting both data and cycle structures for the Cache hit ratio,and improve the performance by 20% for R5000,and moreover,eliminate the potential Cache coherence collision during parallelization.Secondly,we parallelize the solver package MFS with the effective techniques such as cycle combination,domain decomposition and large granularity parallel pipeline.Finally,under POWER CHALLENGE R8000(6 CPUs) and R10000(8 CPUs),we organize the numerical experiments for some three-dimensional three-phase problem with half and one million nodes respectively,and the parallel efficiencies are all higher than 60%.

In modern oil and gas exploration,it is an effective approach to make use of seismic inversion's data for prediction of reservoir and oil reservoir.That can be enhanced the seismic data's utilization efficiency and improved success ratio in oil and gas exploration.RM inversion has illustrated two characteristics.That is the resolution of the log data's longitudinal direction and seismic data horizon direction is high.The condition is constrained by log data and ontrolled by seismic interpretation's horizon.At first,the wave impedance's inversion section comes from the seismic trace of well to seismic data base,leading to calculation of wave impedance inversion's data base and prediction of reservoir sandstone body and oil reservoir's area.In this article,an application example comes from Nugeda area in Erlian Basin,describing stratigraphic and lithological oil reservoir by use of RM inversion.

On the basis of present methods to determine diffusion-absorption property of shale formation,long-core resistivity experimental apparatus has been introduced to study the diffusion-absorption ability of shale formation when exposed to various aqueous solutions.The computer program has been established for using radial resistivity distribution to determine the diffusion-absorption coefficient and the distribution of water content.Theoretical analysis indicates that this method not only reflects the diffusion-absorption performance of formation perfectly,but also provides a fundamental idea to evaluate the hydration ability and hydration state of watersensitive formation in the field.

Offshore production platforms in Bohai Gulf experience ice loading for more than three months each year.The ice load on a platform is much larger than any other environmental loads such as those from waves,current,wind or even earthquake.Therefore,reliability analysis,especially fracture reliability analysis,for the design of fixed production platforms in ice environment or under extremeice-loads is required to be conducted.This paper develops a reliability model to calculate the residual strength concerned with temperatures.It gives a probability distribution of fracture toughness CTOD valueδcwhich accounts for the residual strength of the components at different temperatures.The probability distribution of the maximum stress in the component Which depends on the ice thickness and ice compression strength is also given.According to this reliability model,a calculation method for the reliability of platform components is presented and a computation example is given to show the assessment process.

Based on the interaction of bit and formation,the force from the rock and bit is used for the boundary condition of the end of the drill string.As simplified by the elastic bar theory and FE method,a torsional vibration model for the drill string simulates the bit/formation interaction and elastic deformation of the drill string is established.The torsional model is solved by numerical method by considering the boundary condition and initial condition.The theoretical work in this paper is the basis for the dynamic behavior and kinetics of drilling string and rock bit and for well orbit control early failure prevention.

FEM analyses are carried out to calculate the strength,stiffness and inherent vibration property of model F 1300 triplex drilling pump framework by using SAP5/LISA software.The stress and deformation distribution in every part of the framework under rate load,and the model frequencies of several minimum orders as well as the vibration modes are obtained.The results show that the entire of the framework structure is not even,its strength and stiffness are abundant.The vibration modes show only the stiffness of the pump head and end opening part of the framework is weak,and the middle and inner part of the pump is rigid enough.The structure of the framework is not good.The work of this paper can be used for the design of model F 1300 drilling pump.

Correlation matrix and calculation method of joint parameter of network for low osmose oil field are established,which offer a favorable method for solving network problem with computer.In accordance with the network topology optimization,a mathematics model fitting multilevel optimization arithmetic is established with big system optimization theory.The multilevel optimization arithmetic of low osmose oil field network problem is presented that oil-gas gathering system,sewage dispose system,injection system,electricity system are solved in succession,and the systems are connected with variable,layout and parameter optimization are included in every son system.Objective function of son system is yearly cost;Objective function of overall system is NEPV.The software of optimization of overall planning for surface engineering of low osmose oil has been worked out,and it is science tool of decision-making for exploitation and design of oil field.

A mechanical synthesis method of the systematical linkages for the stroke-increasing mechanism of rod pumping units is introduced in this paper,the corresponding relations between the components in the mechanism and the link-elements in the systematical linkages are determined.The rod pumping unit is synthesized,and several mechanisms and associate linkages for increasing the stroke of the rod pumping units are created.In the light of every synthesis mechanism,the analyses of working loads and calculation of stroke are conducted,and the formula are derived to calculate the force-increasing factors and stroke-increasing ones.Finally,a better mechanism for the stroke-increasing is chosen.

The offshore area is an important part of Bohai Bay Basin.It is the extensions of three depressions,Jiyang,Huanghua,and Lisohe depressions,in the offshore area.Evolution histories of offshore sags are similar to those of the onshore ones.The rising of mantle and the framework of the three surrounding mountains have controlled the formation of the sags,which are controlled by extension faults,instead of strike-slip faults.Tanlu fault does not have great influence on the sedimentary processes in sags.Bozhong sag is different from others,the Dongying formation in which is much thicker and possesses great hydrocarbon generation potential.In the offshore area of Bohai Bay Basin,there are four sags with great hydrocarbon generation potential (Lisozhong,Bozhong,Qikou,and Huanghekou sags) and five exploration fields (uplifts and their plunging ends,shallow structures,buried hills and faulted pre-Tertiary structural plays and slopes of sags).The offshore resources potential is the same large as the three onshore depressions.The offshore area of Bahai Bay Basin has good future in exploration and will become a followup exploration area in East China.

Oil-gas fields in the carbonate rocks mainly distribute along fault belts,unconformity interfaces,reef zones,fissure zones and active source rocks.In China,carbonate rocks in the polycyclic marine basins generally experienced multi stages of reservoir formation,and exploration is difficult in these areas.However,there were some successful examples in Tarim,Sichuan and Ordos Basins recently.The carbonate rocks are important exploring areas to ensure Chinese petroleum industry developing steadily.Therefore,oil-gas field exploration in them must abide by the distribution patterns of carbonate oil-gas fields,and the basic theory studies of carbonate reservoir formation as well as the technologies of petroleum exploration in carbonate rocks must be improved.

Thermal evolution,including Palaeotemperature,palaeoheat-flow and hydrocarbon generation history,is simulated from Sinian to the current by 2-D numerical method based on the tectonic along 11 seismic profiles in Tarim Basin.At several well locations,the simulation results match the measured data well.It is indicated that the thermal evolution from Sinian to the current in Tarim Basin can be divided into four stages.(1)High heat flow(hot basin)thermal evolution from Sinian to Ordovician; (2)Thermal decline from Silurian to later Paleozoic,being ‘hot basin' to ‘cool basin';(3)The stable thermal evolution (cool basin) in Mesozoic; (4 )Thermal evolution of the lithosphere flexibility in Cenozoic.Furthermore,the hydrocarbon generation histories in the three source rocks in Tarim Basin are simulated,and the prospecting accumulations in favorable areas are analyzed taking account of the tectonic evolution.