The Junggar, Tarim, and Qaidam Basins are commonly considered to be cratonic blocks surrounded by orogenic belts and have thus been called inter-montane basins. I propose that those basins be compared to the Black Sea and Caspian Basins,and suggest that Junggar was formed during the Carboniferous Period, and Tarim and Qaidam during the Permian Period, as back-arc basins behind volcanic arcs on the southern active margin of Paleozoic Asia. The relatively thin crust and the presence of very large positive magnetic anomalies under the Mesozoic sediments of those basins indicate that their deepest depressions are floored, at least in part,by oceanic rocks. The oldest sediments in those basin are very likely marine shales. After arc-continent collisions during late Paleozoic and Triassic time, the basins became partially enclosed,and the euxinic sediments in those partially restricted basins could well be the source beds of the crude oils found recently in major oil fields of those basins. Junggar, Tarim, and Qaidam became inland basins with continental sedimentation after their communications to open sea were severed by the rising mountain chains. Isostatic basin subsidence permitted the accumulation of thick Mesozoic and Paleogene sediments before tectonic rejuvenation along Neogene faults.

Based upon the work of many predecessors, this paper studies more deeply the physical relation between formation pressure and interval velocity, and improves two models of pressure prediction reasonably. Then it offers a distribution of abnormal formation pressures of Paleogene in the north sag of Liaoxi depression by excellently using the inversed seismic data.

The crude oil obtained from middle Jurassic in Turpan basin is a paraffinic intermediate one with the characteristics of low sulfur content (0.03-0.06%),pristane predominance, relatively heavier value of carbon isotope than conventional oil/and high content of saturated hydrocarbon as well as low contents of non-hydrocarbons and asphaltenes, etc. Based on a correlation study of oil/source rocks, this paper shows that the crude oil are mainly originated from the coal-bearing strata deposited in a Jurassic swampy-deltaic plain environment.

Assuming that each seismic trace is taken as a discretized time series and a multi-dimensional sample space with various informations, autoregression technique is used, under a condition of minimum loss of information, to find out the space characteristic factor of each sample and thus the number of dimensions is largely decreased, characteristic factors of all seismic traces in a layer are estimated,and are classified by means of multiple distance principle. On this basis, fuzzy cluster technique is used to clusterize all the parts classified in a layer, then, in-layer lateral lithological variation can be divided and classified.Theoretical model is used to verify this technique and this technique is used to process an actual seismic section, and satisfactory results are obtained.

Data of carbon isotope composition of relevant light hydrocarbon monomers, n-alkanes, pristane and phytane are acquired from an online analysis of GC/C/MS of liquid pyrolyzate of some typical source rocks using GC-dalta S gas-MS. The data suggest that the characteristics and distribution model of the carbon isotope of light HC monomers, n-alkane, and pristane and phytane can reflect effectivelythe features of source rock, such as the type of its precursor,sedimentary environment,geological age and thermal maturity. Therefore,it implies a possibility of application of the data in oil and gas geochemical study.

As a basic study of organic source for hydrocarbon generation, geologic environment for the formation of hydrocarbon source rocks has been paid sufficient attention by a number of foreign companies and research departments in universities. Latest achievements in this category are shown in this conference. Based on a comprehensive and multi-disciplinary study, historical and dynamic point of view is applied in computer simulation to restore geologic environment, such as paleoplate, paleography, paleoclimate, to give a prediction and evaluation of hydrocarbon source rocks. These results are of primary importance in the petroleum exploration in frontier areas.

A coordination between well pattern and the area of a sandbody in an oil reservoir was suggested in the previous work [l]. After that a production process optimization model [2] was formulated with performance index for improving oil recovery and economic benefits as their objectives. As its application and extension, this paper deals with the flow and stagnant conditions of remaining oil controlled by well pattern, as well as with a method of identification for the remaining oil uncontrolled by well pattern. As a result, a synergy among various conventional measures for improving oil recovery is suggested and some stimulating approaches adapted for a number of special type of oil formation and its related ideas are presented as well.

The effect of alcohols(n-pentanol toneheptanol) on the micellar properties (micelle formation, polarity of micelle interior, micelle ionization degree (a) and aggregation numbers (N _s,N _A) of the mixed alcohol+surfactant micelles) of sodium dodecyl sulfonate (AS)have been investigated by means of electrical conductivity and steady-state fluorescence methods. The experimental results show that with the increase of alcohol concentration both the CMC and N _s initially decreased to a minimum and then increased,the "a" reached a maximum first and decreased beyond it, but the minimum of N _s and the maximum of a are not observed for n-pentanol. The concentration of alcohols where extreme values of CMC,N _s and a decrease and arranged in an order of n-pentanoln-hexanoln-heptanol. These results have been explained in terms of the effect of the stabilized alcohol in the micelle on the surface charge density, and the dielectric constant of the micelle palisade layer.

Northern part of Daqing oilfield is now entering a stage of high water-cut. It is fairly difficult to keep the stable daily output. A sophisticated study of the remaining oil in the reservoir and its cause is required to make a practical adjustment technique so as to keep a stable production of the oilfield as a whole. This paper, based on a detailed reservoir description well behavior and reservoir behavior (with a sandbody as a unit) analysis, summarizes out a macroscopic method of remaining oil study, gives an analysis of the causes of remaining oil left in the reservoir, and the characteristics of the distribution of various types of remaining oil as well as their ratio, and suggests an effective method in planning out the secondary infill drilling and adjustment program for oilfield development. Actual example is given (a pilot area for secondary infill drilling) to demonstrate the correctness of the conclusion as well as the method of study. Thus, an evidence is provided for a further infill drilling and adjustment program for the oilfield development.

A new theoretical treatment has been developed for computing the average reservoir pressure using an integral of reservoir pressure distribution when the reservoir is homogenous, circular in shape, with a well located at the centre of a circle. The outer boundaries are considered both closed and kept at a constant pressure. This is a precise method theoretically. In the closed case, the relation between dimensionless average pressure and dimensionless time is linear if C _D and S are neglected. When the dimensionless producing time is long, the dimensionless average pressure is almost unchanged, if the out boundaries keep at a constant pressure. According to the results of calculation, a series of graphs and tables of dimensionless pressure vs. dimensionless time are obtained. It is very convenient for practical application in petroleum engineering.

The sweep efficiency of an oil reservoir plays a decisive role in the course of oil production and the ultimate recovery in a large heterogeneous oil reservoir with complex geological structure. The macro-heterogeneity of the reservoir and production technology affecting the sweep efficiency are very complex. It is very difficult to give a simulation description by equations. The refore, no simple and complex calculation model for the determination of the sweep efficiency of a heterogeneous reservoir has been derived till now. Based on a study of factors affecting the sweep efficiency of a heterogeneous reservoir thig paper presents a calculation model for the determination of such an efficiency by means of the theory of probability and method of dimensional analysis.

This paper put emphasis on the researches of Shell-type Azimuth Controller (STAC Tool) for rotary drilling. A new drilling technique of using STAC Tool assembly to control drilling trajectories is proposed and developed. It can be used without down hole mud motor with a bent sub, speed up ROP and improve the drilling quality. This is one of the innovations in drilling techniques. In this paper, a quantitative three-dimensional mechanical analysis has been made by using beam-column theories; three dimensional analysis method of STAC is developed and applied to complete theoretical computations. The results indicate that azimuth can be adjusted and improved by changing some parameters; harmful effects of hole enlargement can be overcome and inclination can be increased by attaching a bent sub at the bottom of the tool. This paper deducted the inherent regularities that influence the new technique. All of these shows that STAC Tool can be extensively used in deviation control. Through practical drilling practices in the Daqing Oilfield and the Liaoho Oilfield, satisfactory results have been achieved, which shows an agreement between theories and practise. Thus this technique can be field applied.

On the basis of an analysis of the existing problems of the traditional design method for the turbocascade of a turbodrill, a CAD software package for the turbocascade has been developed. It includes the optimization of the inlet and outlet flow angles, the moulding design, checking of the design quality, the performance prediction of the turbodrill, etc. The software package has the advantages of high efficiency, convenience and practicality.

Soil corrosivity is an important factor for the design and management of long-distance pipelines. Up to now, none of the methods for predicting soil corrosivity is completely successful in both reliability and flexibility. In recent Years, pattern recognition has become a powerful tool to handle acquisition,trangformation,display and interpretation of experimental data. This paper demonstrates the principle and the procedure of Principal Component Analysis(PCA)for predicting soil corrosivityalong long-distance pipelines. Eleven data groups of weight loss tests along the Cang-ling and the Pu-ling pipelines were gathered as the "learning set" for PCA. Three main characteristics of contents of CaCO ₃, content of total dissolved salts, and soil resistivity were taken as the key parameters.In the planar display generated by the first and third components of PCA, the data set had obvious class separability. The decision rules were also given to predict the corrosivity of soils.The PCA prediction for other 51 soil samples was made andthe results were found in good acco rd with that of the NLM prediction and were proved true by practical records of the pipelines breakdown caused by soil corrosion during the past 10 Years.

A new drill bit nozzle is presented in this paper with respect to the principle of oscillation, physical and mathematical models and the results of in-house and field tests.Addition of such a nozzle can generate strong pressure oscillation to enhance bottom hole hydrodynamic force, pressure gradient and well bore pressure potential,resulting in rock fracturing and bottom clean-up. Under the same operating conditions, the penetration rate can be increased by 35.5-77%, the bit footage by 6-44%.

This paper presents a method for measuring small displacement under water by laser speckle photography.Its accuracy in measuring small displacement in a plane under water at constant temperature is calibrated,and reaches 3 percent, satisfactory in industrial measurement. When water drops falling from 1 meter high with a dropping velocity of 0.2 drop per second are used as disturbance, and when the exposure time varies from 1 second to 10 seconds, the double photographic speckle diagrams of the small displacement are taken.The interference fringes of the speckle diagram may be distinguished and measured by using the analysis method of point by point. The spread displacements on the surface crack center of 16MnR plate sample and on the internal surface crack center of 16MnR spherical sample filled with oil can be measured.The corresponding surface crack stress intensity factor K ₁ is calculated with the combined use of the SCOD method.The test value of the plate sample under this condition is compared with that under normal conditions and with the calculated value of Newman-Raju solution and the results coincide with each other.The test value of K ₁, wkich is the stress intensity factor of the spherical sample filled with oil on surface crack or on internal surface crack is compared with the calculated result based on Schmitt-Kiem formula and the results also coincide with each other. If the influence of water corrosion and other factors is not considered,the measurement of the surface crack stress intensity factor K ₁ of a structure might not be made in water.The calculation of the surface crack stress intensity factor K ₁ of a spherical tank with its ratio of diameters approaching l,can be considered as a suitable plate solution disregarding the effect of the curvature.

This paper studies how the power line loss in a distribution network will increase, if the load changes. A concekt "every hour's equivalant coefficient", is suggested, the range of its values is analysed and some calculation equations are derived. This factor is important for controlling the power line loss in an oil field operated with a large number of walking beam pumping units.

A constructional delta system is mainly produced by the interaction of two different hydrodynamic processes between a river,which carries much mud and sand,and an ocean or a lake.Therefore,it is possible to use some theories of fluid dynamics and sedimentology to construct a mathematical model to describe the depositional process of a river delta,and solve the model by the method of numerical simulation.The application of this simulation may give an insight to the constructional process of a delta framework san dbody and analyze quantitatively the effects of some major factors on the formation of the sandbody,so that the characteristics of the distribution and internal heterogeneity of a deltic sandbody could be predicted.In this paper,the development of Luan river modern delta and the ancient fan delta of Yingtai in Daqing are simulated as examples for the actual application of such a technique.

According to the experimental data of the solubility of natural gas in the formation water with different salinities and types,plats of solubility of the natural gas have been drawn and the equation related to the solubility have been obtained by a regression of related data using a computer in this paper.The characteristic of the solubility of natural gas in the formation water and its geological significance have been studied under various conditions.In this paper,the experimental data of the solubility of natural gas in formation water,the phase state of natural gas and its quantity in its migration state has been studied in Langgu and Baxian depressions,Jizhong region.The resources of dissolved natural gas in formation water are calculated and evaluated in Baxian depression.

This paper was written based on 1851 C _1-4 data from 8153 gaseous samples taken from 16 petroliferous basins spreading all over China.The isotopic characteristics of alkane gases area 1.δ ¹³C values of organic alkane gas increase with the increasing of maturity(R ₀).2.The δ ¹³C values of synchronous and isogenous methane and its homologues increase with the increasing of carban number of alkane gas molecules.3.Theδ ¹³C values of methane and its homologues of coaliferous gas are heavier than that of corresponding component of petroliferous gas from source rocks with the same or similar maturity.4.Part of methane and its homologues components were oxidized by bacteria and resulted in a heavier carbon isotopes in the rest.

In the Linhe depression,there are only 8 wells,distributed unevenly and with imperfection of logging data,so that velocity spectra,derived from seismic exploration are the principal data of this study Based on thesedata,compaction curves and surplus-pressuure curves are constructed and the distribution of subsurface fluid pressure and the condition of oil and gas migration and accumulation in this area are studied.Though the accuracy of the estimation by using velocity spectrum is less than that by using sonic-logging data,however,the conclusions remain to be valid generally.It provides a new practical and feasible method to study compaction and fluid migration in the condition of less namber of exploratory wells.

Based on traditional sefroleum geology,this paper deals with same new conceptions about the fact(phenomenon)that oil and gas pools are mostly distributed tonally horizontaly in many basins both at home and abroad.The author deems that in case of low thermal evolution(Ro=0.4-0.70),it is possible for humic organism to generate enough methane to form giant gas fieldss hydrodynamic conditions(fluid potential)and dextrorotation of the earth are important factors that control and affect the formation and distribution of oil and gas reservoirs.In combination with some actual basins in our country this paper also discussed the rneehanism of zonation of the oil and gas distribution.It will provide some new information and an analytical method for more reasonable deployment of the oil and gas prospecting and exploration.

Based on the study of biomarkers,the oil from L-oil field located on Dongs-ha aplift of pearl River Mouth Basin in China Most of oils from the margins and the surrounding sags of this aplift have similar maturity,same terpenoid distribution,and contain high abundance of 4-methyl-C ₃₀ sterane.These oils are derived from Eocene lacustrine source rocks of Wenchang formation in these sags.The migration parameters of L-oil are much larger than those of the oils discovered in the margins of this aplift,and the carbon isotopes of the saturated alkanes and the aromatics of the L-oil are also lighter than that of the others,these geochemical characteristics indicate that the L-oil underwent a long distance migration.Dongsha aplift is a long time paleo-uplift,having developed basal faults and fractures surrounding the aplift,having an extensive distribution of high porosity marine sandstone and bioherm limestone,and having stable thick regional capping beds.These special geological conditions make the oilstomigrate for a long distance and accumulate enormously in the highs of the basin and form the big L-oil field with a considerable amount of reserve.

This paper studies the formation of a stationary water crest in a two-dimensional flow toward a cross-section in an oil horizontal well located at any position in a vertical reservoir.By using the potential theory for two dimensional floe formulae and plots of critical rate are presented.The results of this paper not only gives a summary of the formula from papers already published but also develops the work presented in SPE paper 15377.

Water displacement characteristic curve is a useful tool in reservoir engineering.It can be used to predict recoverable reserves,recovery efficiency and future reservoir performance in a water drive oilfield.Therefore,it has been widely used in practice.Based on the Buckley-Leverett,one-dimensional displacement theory of oil-water two phase flow,a new relationship between the cumulative produced liquid and the cumulative produced oil is provided in this paper.The application of this expression with actual data indicates that the relationship is applicable and effective.

Starting from two phases(oil and water) Darcy's flow,an analytic expression of vertical flow includding gravity channelling,capillary channelling and additional channelling within a vertically heterogeneous reservoir in a cyclic water-flooding has been derived in this paper.Based on J faction,the characteristics of vertical capillary channelling and its effect have been further analyzed.The difference between conventional water flooding and cyclic water flooding has been explained and the mechanism of improved water flooding within a vertically heterogeneous reservoir by cyclic water-flooding has been demonstrated.A theoretical explanation of the widely used cyclic water-flooding is thus provided for its future use.

In this paper,under the conditions of constant or variable,wellbore storage new models of gas flow are presented,and the analytical expressions of pseudo-pressure distribution in the gas reservoir have been obtained under three kinds of typical outer boundary conditions,and type-curves of pressure-drawdown with variable wellbore storage behavior have been drawn.

Several automatic solutions of the unsteadystate flow formula are rederived with the theory of groups in this paper.Though these equations are well-known and are very widely used in oilfield development practices,their derivation described in the paper is quite unique and applicable.

Only after obtaining the true data about formation anisotropy anisotropic drilling characteristics of the formation can be used scientifically in drilling operations.This paper presents a physical model for evaluating formation anisotropy,which is in the inverse mode of a rock-bit-formation interaction model.Combined with a BHA analysis program,this model can be used to esttimate formation anisotropy from field drilling data.Such a method of assessment can be readily used by field engineers.

Different technological processes of oil gathering and transfering differ in their energy consumption.This paper makes a comparison between a mixed hot oil process and a mixed hot water process by method of exergy analysis.It came to a conclusion that a mixed hot oil process is better than a mixed hot water one for a gathering and transferin system,but the reverse is frue for a oil gathering and transfering station.

An analytical method for the computation of the axisymmetric dynamic characteristics of ground-supported,filled,upright circular cylindrical storage tanks is presented.The liquid is assumed to be non-viscous and compressible.The effects of liquid compressibility and dimensions of tanks on the natural frequencies of the axisymmetric vibrations of tank-liquid system are discussed.An approximate equation for calculating the fundamental natural frequency is derived by an application of Galerkin's method.The natural frequencies and mode shapes calculated by the analytical method showed excellent agreement with those obtained by Haroun and Tayel with the finite element method for tanks filled with incompressible liquid.A number of numerical examples also indicate a good agreement between the analytical and the approximate solutions.

In this paper,a new model for calculating formation forces is developed on the basis of the principle of rock-bit formation interaction and the analysis of the forces on a bit.The emphasis is put on well trajectory change and formation anisotropy in this model.It overcomes the shortcomings of previous models in which formation forces are calculated only on the condition of unchanged well trajectory to make the model more useful.The distribution of formation forces and their influence factors are discussed in detail.On the basis of the actual drilling data from the southern region of Daqing oilfield we have obtained the formation forces and the ratio of formation force to bit weight.The average ratio is 0.74%.

The characteristics and helical angle of the double circular arc gear are very different from those of the involute gear.In this paper the gearing characteristics are described in terms of coincidence,gearing coefficient on a single line and point gearing coefficient.The choice of helical angle is a key in design which is explained in detail in the paper.Their effects on loading capability and driving quality is also presented.The optimum design data for various specific working conditions are recommended.

This paper introduces a new fork-type universal joint on the turbodrill and presents a finite element analysis for the upper joint to determine its.stress distribution and to locate the maximum stress point.On a NJ-100R torsion tester,resistance measurement was run on a 1:2 steel model.By measuring the stress on some surface points and using the freezing slice method of threedimensional photoelasticity,the stress distribution accuracy of finite element ean be obtaived Improved structures of fork-type universal joint are suggested and are used in tool design.

This paper gives four steps to find oil with landsat TM image:"what?","why?","remote sensing expression","oil-gas prediction" and a study of these methods.The exploration method of remote sensing is very successful,because the remote-sensing technique is synthetic,general,macroscopic and visual.Remote sensing technique is advantageous in the plain area covered by thick vegetation.Remote-sensing information is able to prevent arbitrariness in oil-gas exploration with the oil-gas prediction model to increase the success rate and to reduce the prospecting cost.

The area of Taiwan Straits mainly refers to the Taiwan western basin.It is a basin of repeated coverage of about 8,000 meters of total thickness of sedimentary rock during the Mesozoic and Cenozoic Era.Evolution of this basin may be divided into three stages,i.e.,pre-rift during the Mesozoic Era; fault depression of the Eogene period; draping of the Neogene period in the western part of the basin,depression of the Neogene period in the eastern part of the basin.The geological characteristics consist of three types of tectonic framework in the basin,i.e.,zonation from east to west; fault depression-uplift-depression,difference in geology from north to south in the basin,frequent tectonism in multiple stages.Oil and gas prospects for the Taiwan western basin are very good.

This paper analyzes the energy change of underground fluid flow and points out the primary factor which controls the hydrocarbon migration and accumulation is the field of force acting on underground fluid,that is,the distribution characteristics of the fluid potential.By applying the CPPS system software,this paper takes into consideration other geological information and analyzes the characteristics of fluid potential of the main productive intervals of Bozhong field,discusses the direction of the secondary migration of oil and gas and possible accumulation.The following conclusions are reached: (1)From the point of view of energy,the potential analysis method is the correct process for a quantitative study of the process of the hydrocarbon migration and accumulation; (2)The data of formation pressure,which is necessary for the study of hydrodynamics can be predicted with seismic interval velocity; (3)Generally,the secondary migration of oil and gas is from depression to surrounding arch.The best locations of accumulation are shijiutuo-shaleitian and Bozhong depression,the second is Bonan and its northeastern fault zone,the slope between Bozhong depression and Shijiutuo,the Bodong low arch.The prospect of oil-gas resources is more promising in Bozhong field than we know presently.

In this paper,the authors sum up systematically the micro-petrological characteristics of hydrocarbon generation by an investigation of the hydrocarbon generation of many typical source rocks in China in combination with results of thermal simulation test.The relationship of fluorescence properties of macerals or mineralbitumous groundmass(including intensity,alteration pattern and spectrum)versus hydrocarbon generation is investigated.The geological implication of this research is discussed.The micro-petrological characteristics of hydrocarbon generation can be used not only to investigate the migration and accumulation of liquid hydrocarbon,but also to study the maturity and hydrocarbon expulsion efficiency of different forms of organic matter in source rock.

The age of clastic sedimentary rock of the Tertiary Guantao formation to Kongdian formation in the Jiyang sag was determined by using the method of fission track and compared with those ages determined by palaeo-geomagnetic polarity and K-Ar isotope,the results were almost the same.With these data,the sedimentation rate of the layer of the second member of the Dongying formation to the middle of the third member of the Shahejie formation in Well 2-2-18 was calculated,and a new view of the age of the bottom congleremetare in the Guantao formation in this ares was proposed.This achievement provided a new approach to stratigraphic classification and correlation of sedimentary layer,to the research in the formation of oil and gas field and to the quantitative analysis of the hydrocarbon generation from source rock.

This paper introduced the basic concept of reliability and the related knowledge to study the reliability of seismic interval velocity data used to interpret pay zone thickness.Application results of seismic interval velocity data in the Tangyuan depression indicate that the reliability of an interpretation of 25m uncompacted shale,compacted shale,gasbearing layer and oil-bearing layer are respectively 76.1,61.0,43.4 and 25.5 when the seismic interval thickness is 100m and its depth of burial is 1,000m,and their reliability change to 75.4,67.9,56.8 and 29.3 when their depth of burial is 500m.