The numerical simulation of oil/gas basin is a new technique developing for recent ten years.Based on the mechanism of petroleum geology and applying the multidiscipline,this technique can simulate an exploration area(such as basin, depression, sag and sub-sag)to get its geohistory,geothermal history,hydrocarbon generation history,hydrocarbon expulsion history and hydrocarbon migration-accumulation history,and then makes an integrated evaluanon to indicate the favorable exploration areas.Taking the RIPED's BASIMS as a sample,this paper emphasizes the new methods for the five models of the histories mentioned above and the integrated evaluation technique.

Petroleum system,a new concept,had been successfully used in petroleu m exploration and research in Songliao basin in Daqing oil field more than 3G years ago.The quotations from the author's original paper demonstrated that the early raised concept is similar to the concept prevailing abroad recently.However,the latter was presented ten years later than the former.Furthermore,the paper has a discussion on division and evaluation of the main petroleum system in eastein eastern Sichuan, and predicts some new targets of large-medium gas fields.Petroleum system has wide-range application to oil and gas exploration.

Based on analyses of the basin tectonic evolution history and many methods of geothermat study such as vitrinite reflectance,fluid inclusions and apatite fission track,this paper has recovered thermal history of Ordos basin,the temperature gradient was low (2.2-3.0℃/100m) from Paleozoic to Early Mesozoic and increased to 3.3-4.5℃/100m in Late Mesozoic.It has gradually decreased to 2.8℃/100m since Cenozoic era.Research on relations between the thermal history of the Ordos basin and oil-gas accumutation suggests that low temperature gradient and low thermal maturation of gas resource rocks was favourable for preservation of organic materials from Paleozoic to Early Mesozoic.The Late Mesozoic characterized by higher temperature gradient is main period of gas generation and migration of Paleozoic coal series and carbonates.Bacause the temperature gradient gradually decrease in Cenozoic era,the intensity of gas generation gradually decrease or stop.The lack of faults and late gas generation stage in Ordos basin were favourable for preservation of giant gas fields.The central paleouplift in the basin which has good carbonate reserviors and is close to main gas generation regions,it should be the first exploration target to be chosen.

On the basis of log-geology evaluation and norm,combining with logging data,the method of exact evaluation oil-gas reservoir is presented by using grey theory.The interpretation system has been established on every kinds of micro-computer and micro-computer workstation,and applied in different type wells (including straight well,defleeting well and horizontal well)of more than 100 wells in Huabei,Shengli,Tarim,Erlian and Changqing oil-fiel ds,the application effect is evident.The main processing procedure of method,software,and the practical application example is given in this paper.

The volcanic rocks in Fenghuadian area are composed mainly of calc-alkaline acidic volcanic rocks,containing a small amount of alkaline intermediate or intermediate-acidic volcanics.The main oil reservoir porosities in the rocks are primarily vesicles and secondary dissolution openings.The structural and weathering fissures or cracks just were the carrier for transporting petroleum.The volcanics can be divided into three lithofacies:volcanic explosive facies,effusive fades and volcano-sedimentary facies.The reservior properties are closely related with the three facies.Oil is mainly distributed in the explosive and effusive facies.

Studying stress evolution is a key link of basin simulation.The distribution of stress at each stage decided the migratory direction of petroleum and natural gas.Based on the researches of kinematic analogue in the Qintong depression,initial model and boundary condidons of simulation of structural stress evolution have been constructed appropriately.Taken ST365 profile as an example,the characteristics of evolution and the figures of stress σ _x,σ _y and τ _xy at all stages have been given by applying nonlinear theory and plastic flow theory to the study in this region,their geological significance of petroleum and natural gas has been explored.

Based on data acquired from pressurized thermal simulation experiments in which both hydrocarbon generation and expulsion from two brown coals are inspected,the characteristics of aromatic products are studied in this paper.The results indicate:(1)The aromatic compounds bearing substituting groups at the same position as the corresponding biomolecule are the main intermediate products of forming various aromatic compounds from non-aromatic compounds.The dominant evoluationary trend of aromatic compound may be demethylation rather than methylation.(2)A lot of aromatic parameters are sensitive maturation indexes.(3)The substituted aromatic compounds are more difficulty to migration than their corresponding non-substituted aromatics.Therefore, the relevant ratios have the potential to act as migration parameters.

The kerogens in Meishan group of Yacheng basin are typical Ⅲ type.The saturated and aromatic hydrocarbon fractions of Meishan group are predominately cadinene series compounds that originated from polycadinene,which present in dammar resins produced by angiosperm trees.According to optical microscopical analysis results,there are quite low amounts of resinite in organic matter of Meishan group,less than 4% in organic maceral quantitatively,average content ranging from 1.5% to 2%.Resinites are characterized by the very small size of grains which are commonly about 1-3 μm across.Organic matter of Meishan group consisted mainly of amorphinite vitrinite and inertinite.Transmission electron microscopy (TEM) analysis of kerogen ultrathin sections confirmed that submicroresinite were finely disseminated in.amorphinite,vitrinite and mineral-bituminous matrix widespreadly in low maturity (<0.70% R _o) samples of Meishan group,occured in less than 1 μm level in grains size,average content ranging 5%~10%.There are widespread micrinite and submicrinite disseminated in high maturity kerogen.Plant resin materials of Meishan group are mainly in ultrafine size,including submicroresinite and resin compounds.A great contribution to the hydrocarbon generation to plant resin material the rather than resinite is source rock.The results have indicated that Meishan group was good gas source rock,abundant plant resin material enhanced gas-generation potentials in the light of organic matter composition and abundance of Meishan group.

This paper presents an optimized interpretation procedure that is different from the conventional one.This method,based on the slippage velocity model,first builds the theoretical response equation of turbine rotational velocity,average fluid density,water cut,tempreture and pressure,then derives the incoherent function of relative error.The above incoherent functions is transmitted to SUMT-Powell method for optimum processing.This application may improve the accuracy of production logging interpretation of three phase flow.

The pure substance parameters determined for cubic simplified hard chain equation of state were generalized for hydrocarbons as functions of molecular weight,as coupled with the characterization procedure for C ₇ ⁺-fraction proposed by Pedersen et al.,the CSPHC EOS has been applied to predict the phase behavior of reseYvoir crude mils.The test results indicate that,the comparable or better predictions can be achieved as compared with SRK,PR,PT,and DG equations of state,the CSPHC EOS can be applicable to reservoir engineering.

A well test analysis model of a compound reservoir with non-Newtonian and Newtonian fluid flow has been set up.The typical curves and an example have been given.This research can be used to predict well test data with non-Newtonian such as polymer fluid flow and locate the polymer flooding frontier.

The prediction research of petroleum reservoir development targets are closely related with the economical effect of future petroleum research reservoir operation and the fuse of technology application.In order to make the long-term production schedule and annual plan reasonably,on the basis of science to develop the field to full potential extent,it is crucial to study the production prediction method for field blocks,and this could result in optimization production scheme.This paper takes of the advantage of current achievements in establishing of differential equation time continuous model of dynamic system,in system engineering field,and presents a new method of target prediction in petroleum reservoir development.This model is named CDM (n,h) model,and CDM (n,h) model cad be used not only for prediction,but also for dynamic system analysis and control.Applying this model to predict practical production showed satisfied precision.Compared with GM(n,h) model of Grey System Theory through many practical data from production process,CDM,(n,h) model has obvious advantages.

According to the mechanism of heat conduction and heat mass transfer,this paper establish a mathematical model about the temperature field,and gives its initial and boundary conditions and a numerical solution method.The optimization identification model of the heat-conduction coefficients and specific heat are presented.The algorithm,application and numerical results are discussed.

In this paper,a multi-step generalized gradient method estimating model parameters and a multiple stage curve fitting method building models are put forward.They are successfully applied to modeling of an oil field flood pattern.These models are with very high precision.

A mathematic model of surfactant loss in one dimension for flow state (see Equation (5) or (7)),has been derived from theory of mass transfer.It was presented that the equation was resolved with the differential method.This model was examined with the changing of the length column packed Laojunmiao reservoir sand as well as the changing of flow volume injected flooding solution.Experiments showed that under above conditions prediction from the model were of good agreement with the experimental data.

This paper presents the governing equation of static behavior of a bottomhole assembly in 3-D space and the general solutions of their simplified modes. A vector model of rock-bit interaction is developed by accounting for the anisotropic drilling characteristics of both the formation and the bit.This paper discusses the basic principles of predicting and controlling the wellbore trajectory.

Marine risers system is one of the major equipments for offshore drilling.Simplifying the four-order nonlinear partial differential equation and boundary conditions for describing marine risers motion,a nonlinear dynamic analysis is numerically simulated by using a finite-difference method.The top tension on the marine risers is studied,using four seastates which correspond to increasingly severe drilling modes:normal drlling condition,limited drilling condition #1,limited drilling condition #2,and suspended drilling condition.The calculation program has been completed.Numerical results are compared with those obtained by STRESS ENGINEERING SERVICES INC.U.S.A.,there is no difference.It is shown that the dynamic analysis method and computing program in this paper are simple,accurate and time-saving.It is applicable to the design and check of the marine riser system.

Nu-MH-1 horizontal well was the first large radius horizontal well drilled in Dagang oil field.Up to now,it is also the deepest horizontal well drilled on the national onshore.Because the uncertainties of the pay zone top depth and wellbore turn-off direction affected by the formation,it made controlling the wellbore trajectory very difficult.This article introduces Nu-MH-1 horizontal well from the property of the pay zone formation,the well production,the drilling programs and also analyzes and discuss the Nu-MH-1 well trajectory control techmques.

In microscopic view,the group of cuttings is discrete,its motion and collision between the cuttings are strongly random.In macro-scale of time and space,the dispersed cuttings phase is assumed to behave as continuous medium,which is termed "pseudo-fluid",and its dynamic regularity is shown in the view of statistics.Based on this concept,a serious of important problems in the transport of the cuttings carried by drilling-mud are studied systematically,such as the shearing and the random collision effects between the cuttings,the interaction between the drilling-mud and the cuttings phase,the interaction between the cuttings and a wall.The dynamics mechanism of the cuttings transport carried by the drilling-mud is revealed,and a two-fluid governing model for the drilling-mud and cuttings mixture flow is generated.

Properties of angle deformation have been deeply studied,the stress calculation formula that calculating angle deformation of spherical shell is derived.The deformation feature of spot where angle deformation takes place is given.The numerical expression of quantity relations between the limit capacity of angle deformation and the structure of spherical shell have got,tests show that it may be used with JB1127-82 standard.

A series of tests in laboratory and field on liquid-liquid separating hydrocyclones were made through separating two kinds of oil-water mixture ;crude oil-water and machine oil-water.The effect of geometry and operation parameters of a hydrocyclone on separation efficiency was systematically studied,and so some relational expressions were proposed.Based on above works, two kinds of hydrocyclones (D=38mm and D=52mm) were designed and manufactured.It was confirmed through field test separation efficiency of the hydrocyclones is more than 90%, and it has simple structure, lower costs and lower energy, and operated at low pressure, so that can be used in engineering practice.

The influence of the temperature on the growing of sulfate-reducing bacteria (SRB) and the effection of SRB on corrosion of sheath-tube in oil field are studied in this paper.The influences of temperature and the concentration of Fe ²⁺ on the corrosion of carbon steel induced by SRB are analysed emphatically.Experiment shows that the activation of SRB is the strongest at 37℃, the existence of SRB increases the corrosion to carbon steel,and,the effection of SRB corrosion by Fe ²⁺ is related with the temperature: at 37℃, Fe ²⁺ increase the SRB corrosion,but it reverses at 60℃.These results agree with the phenomenon of inner corrosion of sheath-tube of Wen 10-1 in the Zhongyuan oil field.

The hoop stress field in a thick-walled cylinder of chemical vessels with internal surface single or multiple cracks have been determined by means of 3-D photo elasticity analysis.The "Load Relief" mechanism of internal surface multiple cracks are studied.As a result,the concept of "Non-Dimensional Additional Bending Moment"(m)and expressions have been found.The regular variation of the m with cracks position(θ),depth ration(T)and shape ratio (S) are given.The relationship between the m and "Load Relief Factor" (LRF) is explained.based on author's former works,the LRF of semi-elliptical multiple cracks which are radial symmmetric array in an internal pressurized thick-walled cylinder is established,then an expression and regular variation of Stress Intensity Factor (SIF) from the LRF are obtained.

The formation of coal measure-derived oil ggs fields in NW China is the product of the assemblage in spatial and temporal domains of certain tectonic conditions,sedimentology and the accumulation of oil-prone organic materials as well as the effective expulsion of oil gas from the coal measures.The study made by this paper shows that the following.conditionsare necessary for the formation of coal measure-derived oil gas fields in Jurassic sequence of NW China The Jurassic original basin,which was occupied by lake water or low-positional swamp during the most Jurassic time,should exist,so that the complete association of source rock,reservoir and caprock was well developed;The original depositional environment was characterized with low and gentle depression and humid climate which are favorable for the development of low-positional marshland and lake where the oil-prone organic materials were accumulated with large volume;The sequent basin should occur on the Jurassic original basin which is necessary to keep the coal measure source rocks in the condition of progressive mat uration,and certain degree of tectonic compression taking place soon after the maturation of source rocks can provide the driving force for the effective expulsion of oil gas from the coal measures.Coal measure-derived oil gas fields is horizontally distributed along the inner side of lake strandline depositing with source-rock and vertically occured above or below the thresh old of maturity.Owing to the sharp variation of lithology and facies in coal measures,the lithological and composite types of oil gas pools play a big role in the petroleum accumula tions of coal measure sequence.

Songliao basin is one of giant rift basins formed in the late Mesozoic.Its evolution represents successively rifting stage,postrifting stage and compression-subsidence stage.During its evolution process,there were three times of tectonic inversion:the first one occurred in the rifting stage,being a negative inversion related to the forming of fault depressions;the second and third ones occurred respectively at the end of the rifting stage and at the end of postrifting stage,both being positive inversions,which remoulded the protobasin.The negative inversion represented the reviving activities of early thrust faults(system)with upthrows sliding downward along the trend. The positive inversion process was contrary to the negative one,formed fault-bend and fault-propagation folds.The Precenozoic framework of structures in Songliao basin formed in the third inversion,horizontally forming structural belts along the trends NNE-NE with transformation intensity weakening from east toward west and from south toward north,and also showing a relationship with the distribution of oil and gas fields.

Vitrinite reflectance of dispersed organic matter in Triassic of well Qing 36 in Ordos basin(i.e.Shanganning basin) range from 0.61% to 1.06%,yielding a higher coalification gradient of 0.36% R _m/km.According to different analyses ,it is concluded that the palaeogeothermal gradients in the Mesozoic could be up to 35-57℃/km and exceed present geothermal gradients(22-27℃/km).Other geothermal analyses (microthermometry of fluid inclusions and occurrence of laumonite)support this conclusion It is inferred that the higher palaeogeothermal gradients may be attributed to either a thinner crust during Mesozoic,or to a short thermal event at the end of Middle Jurassic,or to both of them.The higher palaeogeothermal gradients played an important role in the formation of hydrocarbons,and have significant influence on oil and gas exploration.

In the light of natural gamma ray spectrometry(NGS) data obtained from 644 pieces of core samples of 27 exploratory wells and lithologic parameters of these rock samples tested and analyzed in the laboratory.the distribution regularities of radioactive elements,Th,U,and K,in the region are discussed. Proceeding from geological and physical conditions,mathematical relations between gamma ray spectrometry and lithologic parameters such as shaliness,mid-value of grain size,cation exchange level,the ratio of aluminium to silicon,etc.are established.This provides a full theoretical basis for the evaluation of formations and for the interpretation of well logging data of natural gamma ray spectrometry in the region.

In the comprehensive evaluation of objective specific properties of an object,the weight definition is a puzzling subject of importance,and for a long time no effective solution has been made.Given the example of study on selection of target zones and well locations for the gas-bearing carbonate reservoirs in the south Sichuan petroliferous region,with an approach of grey relationship analysis,it is first pointed out that the weight definition bears significant implications and that the approach of grey relationship analysis can play a viable role in giving a solution to the subject.On this basis,the principles and methods for weight definition are elaborated from the theories to go by and to the processes to carry out.A sound approach is provided for definition of indexes weight in the comprehensive evaluation of hydrocarbon reservoirs.

With a view to finding out the characteristics of alkane generation during the thermal evolution of kerogen,alkanes generated by kerogen in lignite and by total organic matter(kerogen and EOM) of lignite are studied through two series of pyrolytic simulation experiments.The results show that kerogen can't be directly degraded into light oil,and that alkanes in the products from kerogen degradation do not show any odd or even preference,and that the pristane to phytane ratio is relatively high and does not vary sharply with variation of temperature,and that the pristane to nC ₁₇ and phytane to nC ₁₈ ratios decrease linearly with the increase of temperature.In the products from the thermal degradation of total organic matter of lignite,there is light oil generated; alkanes generated during the lower temperature stage show quite strong odd and even preference;the pristane to phytane ratio becomes first larger and then smaller while temperature is rising;and the pristane to nC ₁₇ and phytane to nC ₁₈ ratios rise up and drop down repeatedly following the rise of teniperature.

On the basis of summing up the features of hydrocarbon distribution in cap rock,the genetic mechanism of hydrocarbon vertical distribution in cap rock is analyzed by applying hydrocarbon geochemistry theories and also theories regarding hydrocarbons sealed by cap rock. The hydrocarbons in cap rock are composed of "residual hydrocarbons"and "occluded hydrocarbons", which stack each other.The residual hydrocarbons mainly distribute in the middle part of cap rock with hydrocarbon composition variation controlled by the effect of cap rocks to expell hydrocarbons;while the occluded hydrocarbons mainly distribute in the lower part of cap rock with hydrocarbon composition variation controlled by the effect of vertical migration of hydrocarbons.The genetic model of hydrocarbon vertical distribution in caprock is established.Also discussed is the role which can be played by the regularities of hydrocarbon vertical distribution in cap rock in studies on cap rock and searching of gas reservoirs.

In order to meet the requirements of annual planning and long term programming,the major indexes of heavy crude reservoir performance during the huff and puff process are comprehensively analyzed and studied on the basis of large amount of field data and by applications of system engineering theory,reservoir engineering method,as well as mathematical statistics method.Their variation regularities are summarized.The reservoir performance forecasting model is developed and a forecasting method is inferred.

A two-step strategy to enhance ultimate recovery from oilfields is set forth:the first step is to enhance water drive recovery efficiency on the basis of present oilfield development status and by making use of up-to-date science and technology,the second step is to adopt new technologies for enhancing oil recovery efficiency in order to further improve the ultimate recovery from oilfields.The regularities of water cut growth in water-drive oilfields are analyzed,and their residual oil distribution status is studied.The potentiality of water drive oilfields is pointed out.Finally discussed and commented are various effective approaches to enhance water drive recovery efficiency and their developing trend.

Alternative water shutoff agents comprising TDG-IR and TF-3 as main components are presented.Also presented are the studied relevant factors affecting the performance of water shutoff agents.Both sirnulations of reservoirs physicochemical conditions and tests in-site of oilfields prove that this type of water shutoff agents has the alternative of water and oil and the high compressive strength and low viscosity of base liquid during the water shutoff job.They were also proved to be capable of carrying all kinds of solid filling materials and adapting themselves to a broad range of temperatures,to have the possibility of readjusting gelification time and the simplicity of application process and the relatively long effective period.They represent today a new type of domestic water shutoff agents with better performance.

It is considered as a prerequisite for the optimized oil production planning to accurately predict oil production.On the basis of reviewing numerous existing methods for prediction of oil production,a multimodel adaptive prediction method is developed.This method derives from the single-model adaptive prediction technique.It can not only best match the variation regularities of the predicted object with the different trajectory equations existing at different time intervals,but also make the parameters involved in the best matching equations timevarying.Hence it represents a perfect adaptive system,and possesses features of high prediction accuracy, good adaptability,simplicity of calculation and convenience.

The governing equations of the helical flow of non-Newtonian fluid in eccentric annuli are theoretically established.They are the 4th order nonlinear nonhomogeneous partial differential equations with variable coefficients expressed by the stream function and axial velocity in the bipolar coordinate system.The calculation steps of the finite difference method of these equations are given.Given the examples of experimental data of water and CMC aqueous sol ution from laboratory,the velocity distribution functions of the helical flow of non-Newtonian fluid in eccentric annuli are calculated and analyzed.The results show that there is a secondary flow involved in the helical flow of the non-Newtonian fluid in eccentric annuli,and that the eccentricity is a major factor to exert influences on the size of the region of secondary flow.

A two-dimensional physical model is described. lts inside is visible.This is a distinct feature of the model.The flow of injected water through the porous media in the model can be directly observed.In accordance with the geological characteristics of layered reservoirs and the differences of properties of the crude oil in these reservoirs of Liaohe oilfield,simulation studies on waterflooding processes in layered reservoirs were conducted by making use of the above mentioned two-dimensional visible model;these processes included concurrent waterflooding in layered reservoirs,shift of water injection from lower to upper after lower reservoirs haying been water-flooded,and waterflooding only in the lowest reservoirs to form artificial bottom water drive.The development performances of these different waterflooding modes are compared and their respective development mechanisms are studied.

Horizontal wells in a low permeability reservoir often need hydraulic fracturing treament in order to stimulate production.After the treatment a number of vertical fractures are normally formed.Well tests conducted in horizontal wells with a number of such fractures are analyzed.So far papers about this subject are scarce.It is attempted in this paper to analyze the process of fluid flow through pay zones in a horizontal well penetrating an isotropic reservoir with several vertical fractures created by fracturing treatment,and to develop a new mathematical model of fluid flow through pay zones in such a horizontal well.A dimensionless bottom-hole pressure can be computed by using a new method of integral transformation.The values of such pressures have been used to plot bottom-hole draw-down curves,which can be provided as theoretical charts for well test analyses.A concrete interpretation method is given together with a field example;the fracture half-lenth,fracture conductivity and formation average permeability can be determined.

In the light of the theoretical model of multivariate power product of lateral cutting and the theory of bit-rock interaction,it is shown in the paper how an integrated effect can result from effective actions of the axial and lateral forces of bit taking account of the formation factors and the bit characteristics related to its mechanism of cutting and breaking rocks.Also shown is the calculation model of displacements of borehole resulting from the above effect together with factors such as the well depth increments,the bit rotating speed,the borehole headway direction,the formation drillability,etc.On the basis of theoretical and experimental studies,the application software has been developed.The theoretical achievements and the calculation software have been successfully applied to the lateral section control of horizontal wells in Daqing oilfield.The results showed that the calculation model developed on the basis of integration of the approach of theoretical analysis with mathematical statistical analysis on actual drilling cases is an effective way to predict the lateral sections of horizontal wells.

On the basis of spatial truss model, both the geometrical and the material nonlinearities of the structure of a rig derrick under working conditions are fully taken into account,and the derrick load capacity is studied.A basis of structural analysis is provided for indepth studies on safety and reliability assessment of the structure of a rig derrick under working conditions.

Major factors having influence on the ultimate collapse strength of casing are represented as the ratio of diameter to wall thickness,the variation of wall thickness,the initial ellipticity and the material mechanical properties of casing.These factors are analyzed and calculated.Also represented are some fundamental concepts of designing the ultimate collapse strength of casing,and theoretical explanations of some coefficients involved in relevant equations,as well as some proposals regarding the calculation of the ultimate collapse strength of casing.The theoretical analyses and calculations represented in the paper can be applied to practical enigneering.