Through the experimental study of existing evaluation method of mud cake compressibility, this paper compares the compressibility under normal temperature static / dynamic state, with three evaluation methods-"cake percotation rate","penetrometer", and "two stage water loss". The result shows that it is convenient to evaluate mud cake compressibility by means of "two stage water loss" method , especially under no mud-pouring, and the data is reliable. The compressibility of mud cake is resulted from both elastic and plastic deformations.
According to the equitime character of seismic reflection and the characteristics of seismic atratigraphy, the authors have classified and traced the layres of Xiangqi Group in Central Sichuan-South Sichuan transitional belt, and provided the fundamental data for the further study of the layres.
Classifying-formation from logging curves is a basic step in the course of automatic electro-facies analysis. This paper studies the method of automatic classifying-formation in a deep going way on the basis of thorough analysis of many normal methods, and uses max-minimum and variance technique to solve this problem. Taking S3formation of complex rocklitho profile in 08 well and other boreholes . The result shows that this method is not only easy, practical, but also fast in calculation and reasonable and accurate in classifying formation. Therefore it can be adopted for reference and applied in fine log facies analysis.
On the basis of systematical research on the chemical behavior of reservoir minerals in alkaline-flooding agents, the authors put forward a mew idea that alkaline diagenetic setting is favorable for the formation of secondary pores in sandstone reservoir. Furthermore, the authors suggest an “acid-alkaline chain reaction” model for a mono-system, and prove the existance of alkaline diagenetic settings through rock mineral composition analysis and the reference of literatures. Obviously, the idea has positive effect on oil /gas exploration.
According to the actual condition of Shengyang Oil field reservpor. 7 formation micro-models were made with the core casting slides of Well Jing 11 and Wells Jing 63-27 in Shengyang Oil field. This paper introduces the direct observation and research of the influence of the crude oil viscosity of S43reservoir in Shengyang Oil field and porous construction on displacement mechanism and efficiency, and the distribution charecteristics of remaining oil, by using micro-visual physical simulating technique, and with the help of microphone, camera and video recorder, and picture analysis technique, dtc.
Rules of weightlessness and air cutting in highly derivated and horizontal wells are not the same as in vertical wells, which lies in the effects of cement slurry filtration rate, hole derivation angle, well calibre and well structure, etc. Weightlessness and air cutting of zero-filtrateless cement slurry result from suspended agglomeration, but those of non-zero-filtrateless cement slurry are caused by free water groove formed on the upper wellface as well as suspended agglomeration. The study also shows that the filtration rate of cement slurry measured with API normal method is not reasonable and it must be measured with the measuring tube inclined 45℃.
Basing on rock scouring of nozzle jet, this paper analyzes the rock- breaking way of rock bit, the mechanism of main and auxiliary hydraulic rock breaking and the basic action and effective factors relating rock breaking. The result shows, under the conditions of current pump unit, rock bit nozzle jet has a direct rock- breaking action on mudstone,shale and coarse grain sandstone, and an auxiliary one on limestone and fine grain sandstone. The impulsive pressure of nozzle jet, the jet pulse property, the rock porosity and the developing condition of fracture are three effective factors of main and auxiliaty hydraulic rock breaking.
Activity equilibrium theory was presented long ago and applied to evaluate and design of anti-sag property of mud filtrate. However, since it is impossible to take water sample from shale formation, so far we haven' t found a way to determine the ionic activity of water solution in shale formation through laboratory experiment. Therefore, its application in shale formation had always been restricted. In this paper, a theoretical research is made on the application of geophysical logging in this domain. The results show that it is possible to determine the ratio of mud filtrate to the ionic activity of formation water solution and the iomic activity by making fukk use of the present log data combining with the dual water model of shaly sand formation. Accordingly, anti-sag property of mud filtrate can be adjusted, or the bydration of mudrock can bi conteoled.
Based on L K Thomas et al' s basic idea of dual porosity, single permeability model, the paper has put forward a new, overall, full-implicit three-dimension and three-phase model of horizontal-well in fractured reservoir, comprehensively considering the relation between oil and water, or oil and gas, capillary imbition, gravity drainage。
This paper makes a research on the mathematical model of productivity prediction in view of the four completion methods or horizontal wells of perforation series, such as casing perforated completion, inside casing wire wrapped screen, inside casing gravel pack, inside casing prepacked gravel liner and in consideration of the effect of formation damage, well completion methods and well completion parameters on the productivity of horizontal wells. Example calculation shows these mathematical models and their calculation methods are feasible and can be used in the optimum selection of well completion methods and the optimum design of well completion engineering.
Since 1982, grey system theory has been widely applied in many realms, but its application to predicting reservoir performance is much limited, and its effect is not very ideal. This paper expounds the basic concept with grey system theory, and successfully predicts various development indexes in the light of actual production data of reservoir. The result is quite accurate and reliable.
A pre-proceeding method of the pressure measuring data in well testing is presented in this paper. Using the pre-proceeding method of signal arrangement, adaptive Kalman filtering and B spline function fitting, we can obtain the pressure and pressure derivative at random point in testing time. Two examples illustrate the characteristics of the method.
this paper introduces a fuzzy reasoning system used in the prediction of sidewall stability. The system consists of dynamic data base, knowledge base, fuzzy reasoning and man-computer interaction and it has been proved to be valid by the practice in some directional inclined wells in Chang Qing Oil-field
This paper introduces a number of indoor physical simulating experiments with 215.9XHP 25-1 and 215.9 HPZ soft formation roller bits used in drilling Zizhong-sand and Jiayi-Limestone. The relationship of the torque and the penetration rates of the two types of bits varying with the bit weight and their average drive ratio are obtained through data collection and data processing system. and some important experimental data are provided for the improvement and design of the two types of soft formation roller bits.
This paper systematically studies the relationship of the geometric structural parameters of PDC bits, and derives the essential equations of PDC bits geometry without making any hypothesis and simplification. The essential equations can be directly applied to the studies of PDC bits kinematics and cutting mechanics, and the bit design, eliminating counting errors caused by geometric simplifications.
A jet Pump s performances are characterized by its efficiency, cavitation and submerence from different aspects. This paper gives a detailed analysis of the factors affecting the jet pump performances and the law of their change from the three aspects respectively, so as to present a reference for the application of jet pumps in oil fields.
This paper discusses the problems on the loading response combination of combined-arched pipe bridge and the statistical analysis of the component resistance of the structure, sets up the failure criteria for the components of the structure, and derives the formulas to be used for calculating the itemized reliability indices of the pipe bridge by using the centre-point method of the first-order second-moment theory. They formulas can be used as the basis of reliability analysis and the design of combined-arched pipe bridge.
This paper briefly introduces the types and mechanism of flame retardant, and its application and development at home and abroad.
Lignosulfonate can be synthesized with the scrap produced in alkali papermaking process and it can further be mixed wity 4 % FeSO4•2H2O into a slurry deluent. The determination of the slurryoperties shows that it has the characteristics of good temperatureresistance and dilution effect, and certain water-loss capacity as well. At the same time it eliminates the pollution of chromium to environment.
On the basis of an example of the technological scheme design of recovering light hydrocarbons, a study is made on the scheme of recovering light hydrocarbons from small flow and low pressure gases. A rational scheme of recovering light hydrocarbons is achieved through technological calculation, parameter analysis and scheme comparison.
Basing on the analysis of the characteristics of the large-scale engineering systems d their total operational models, this paper puts forward the concept of the evaluation of rge-scale engineering systems, and establishes a corresponding evaluation model. In addition, this paper makes a preliminary research about the evaluation of the structure, environment, input and output, feedback, characteristics and operating state of the largeale engineering systems.
In view of the fact that programs written in C are widely used at present and programs written in Fortran were often used in engineering computations, this paper holds that the function modules written in Fortran can be called from programs written in C , which is very useful in solving some actual problems. The purpose of this paper is to provide the points for attention in the calling processes mentioned above.
Basic research brings about high technology and is an important way to improve teaching and cultivate senior specialists. It is also an important measure to enhance the competition at high levels. In order to win the future competition , universities and colleges must emphasize the basic research to stabilize the research ranks and have their own strength, superiority and characteristics so as to be able to exist and develop.
