In this paper, we provide a numerical method for the solution of elastic wave equations in fluid-saturated porous media, and derive its calculation formula. Using thes formula, we simulate the wave propagation in a fluid-saturated media model with one reflection plane,the result of which is corresponding to Biot's theoretical prediction.
Well-bore collapse in Naduzu shale has been the peimary factor that interferes the drilling in Huacha, Nakun area in Bese Basin, Guangxi. This paper focuses on the mineral content, pore and fissure configuration and the physiochemical properties of Naduzu shale,and provides scientific basis for researching the unstable factors of the well section in Naduzu, and the effective measures of preventing well collapse.
It is not quite reliable to model fluid flow around horizontal wellbores with conventional reservoir simulators of rectangular grid system due to the fact that the fluid flow is found to be a radial flow. In this paper, we simulate the radial fluid flow around the horizontal wellbores with an efficient method of hybrid refinement around the wellbore by combining rectangular gridblocks with the radial gridblocks. We also choose the 7th SPE comparative Solution Project(SPE 21211) to demonstrate the effectiveness of the model.
On the basis of(6), this paper establishes, for a number of gas reservoirs to be exploited, the exploitation priority evaluation index system and its structural model, and sucessfully arranges the order of prior exploitation of multiple gas reservoirs to be exploited, combining the improved AHP method and approaching method, and taking into account the effect and the investment.
Huanghua Depression is rift of Bozhong Triple Rifts that have the features of mantle uplift，high—heat flow and strong volcanic activity. Four tectono—stratigraphic units in this depression exist in each of the three tectonic levels. The evolution of the rift basin underwent three periods of tectonic movement patterns with different orientations:①During the pre— rift period，the compressive orientations with S—N direction. NW—SE direction and NWW —SEE direction were produced by the Indo— China Movement，the Early Yanshan Movement and the Late Yanshan Movement respectively;②During the rift period，two phases of rifting with the extensions of NW—SE and S—N direstion were produced in the depression;③During the post—rift period，the tectonic movement changed from horizontal movement to vertical subsidence because of the shrinkage of the rift.
In this paper，the mechanism of movable pressure—variable volume karst is provided for the study of the effect and characteristics of carbonate fissure—cavern system karst. The author thinks that horizontal stress field mainly controls the intensity and distribution of fissure—cavern system karst，and fissure—cavern system karst effect is one of the factors that bring about such geologic phenomena as the abnormal high pressure in gas reservoir and the wider distribution of gas concentration.
According to the 369 core mercury—injection data from 9 wells，this paper studies the throat types and pore structure parameters of the main flowing throats of Triassic reservoir，such as the average. throat radius(Rz )，throat deriation coefficient(α)，throat pore structure coefficient(F), and derives an analytic expression of the interrelated pore structure parameters and the physical properties of the reservoir. This paper also introduces the throat distribution under stratum stress first obtained through the horizontal one—way flowing mercury—injection test under effective stress.
Neural network is a new information processing technique，which can be used to solve the problems of log interpretation, pattern recognition and parameter estimation in reservoir description. Using the formation porosity and logging data of cored well of Moxi gas field，we have successfully applied Back Propagation Network to the establishment of a prediction model of calculating formation parameters-porosity. Compared with the traditional methods—Regression equation，Grey equation and log interpretation，its precision and predicted result are rather satisfactory. Thus this method is well worth popularizing.
In view of the features of steep structure，deep carboniferous reservoir and the low signal noise ratio of seismic reflection wave in Eastern Sichuan region, this paper presents the method of predicting gas reservoir with seismic data，and makes a study and prediction experiment on the to seismic profiles by this method，and acquires good results. Besides this paper specially introduces the model migration calculation method .Through drilling tests，it proves that this calculation method can be effectively used to calculate the two problems of structure migration and prediction point position migration.
This paper discusses a method of analyzing trace heavy constituents and single hydrocarbons (not more than C9) in natural gas. On the basis of analyzing the present problems in natural gas analysis，this paper presents a new and simple method of concentration which can be used to analyze and determine trace heavy single hydrocarbons in natural gas. Experiment results show that this method is feasible.
Tarim Basin is a Mesozoic—Cenozoic superimposed oil—bearing basin developed from the Paleozoic platform. As it has long been in relatively stable tectonic setting，it provides the favorable geologic conditions for oil—gas generation，accumulation and preservation. A lot of oil and gas seepages and the prolific oil—gas wells indicate that Tarim Basin is rich in oil—gas resources. Among the mufti—oil—generating beds，the Cambrian and Ordovician is the best one. According to the Cabrian and Ordovician petroleum geologic features，the author analyzes the oil—bearing potential in the basin.
This paper analyzes the complexity and its reason of Xishanyao and Badaowan coal seam wellbore in Tuha Basin，and emphatically discusses the mechanism of the coal seam wellbore unstability. The result shows that coal seam wellbore unstability is a synthetic effect caused by such factors as physics，chemistry，mechanics and machinery.
Reverse circulation kill method was much used in workover well control. As it has such advantages as quick removal of well kick，less pit gain，and small casing pressure，it can also be cased in well completion and drilling well control. This paper introduces the technology of the reverse circulation kill method，presents the calculation method of drill pipe pressure and casing pressure influenced by flow resistance，and compares this method with conventional driller's method and engineer's method when it is used to calculate practical examples.
Horizontal well is an important means of the recovery of fractured reservoir. In view of the seeping characteristics of the fractured reservoir and Permeability anisotropy reservoir, this Paper establishes a Percolation model of horizontal well，and obtains its solutions by finite Fourier transformation method. Besides，this Paper also draws the chart boards of dimensionless Pressure and dimensionless velocity. According to the law that dimensionless Pressure and dimensionless velocity vary with time and space，the Paper Presents the horizontal well seeping characteristics of the above two types of reservoir, favorable extension orientation of the horizontal segment of horizontal well and effective technological measures of increasing Production.
In view of the lost—circulation physical property of Luohezu sandstone in Eastern Gansu axes of Changqing Oilfield，an esperimental study is made by using the bridge—shielding principle. A reasonable bridge plugging system is set up on the basis of the adjustment of the size distribution of calcium ,carbonate and the choice of water—loss control agent as filling agent. The tests both in lab and on site show that this system can improve the compressive strength of the lost—circulation formation and meet the needs of drilling and well cementation project construction.
The geologic structure of the Xihu concave of the Eastern Sea is very complicated，and the fluid properties are even more complicated. The data of about ten test wells show that there are oil，gas，gas condensate, volatile oil，and oil—water and gas—water phases in the fluids. A thorough theoretical study has been made on DST and slug well test interpretations and a set of modern DST well test software has been developed，which is suitable for the complicated geological structure and oil and gas fluids.
Compared with an integral stabilizer with fixed diameter，a stabilizer with variable diameter can effectively ensure the quality of a well body，and is one of the most advanced drilling tools，The stabilizer with variable diameter discussed in this paper is a deep well stabilizer with variable diameter，which has been developing jointly by our institute and a mechanical factory under Sichuan Petroleum Administration Bureau，and which is now being trial—produced. So far no other similar products have been produced in China. In this paper the finite element method is applied to the detailed analysis of its strength and stiffness，and a reliable theoretical basis is provided for its design.
As is known，the hydraulic performance of a reciprocating pump is affected by its suction system configuration. in order to study how the suction system configuration affects the pump's hydraulic performance，this paper analyzes the working performances of the reciprocating pump with changeable suction system configuration，and the relation between suction performance and suction system configuration，thus determining the best suction system configuration. The experimental results show that the pump's hydraulic performances have much to do with other important phenomena，which were observed and analyzied during the experiment.
Hydrocolones used for used for separating the sand in producing fluid are different from those used for processing drilling fluid in their working conditions and service requirements. According to these differences，this paper discusses，by means of indoor hydrocolone test, the main factors affecting the separating effect of hydrocolones used for separating the sand in producing fluid，and points out the main features of hydrocolones in design and use.
A new kind of cationic polymer-a copolymer of acrylamide-dimethyldiallyl ammonium chloride, has been synthesized. The synthetic conditions have been discussed and a study has also been made on its properties，such as salt-resistance, temperature tolerance，flocculability, inhibition of corrosion and stability.
This paper describes the method of preparing the cationic monomer with acrylamide，2-chlovoethanol and dimethylamine. The homepolymer of N，N-dimethyl ethylacrylamido ammonium chloride，and the copolymers 'of acrylamide with DEAAAC are synthesized with prepared positive nitrogen cationic monomers. Besides the polymerization conditions are determined and some structure parameters of polymers are measured. In this paper the relations are also analyzied between the properties of swelling—prevention of clay used for mud and the composition of the copolymers. The paper concludes that the cationic degree of polymers can be adjusted by polymerization conditions according to different clay swelling—preventing requirements.
The method of establishing differential equations with self-induction and mutual-induction electromotive force and the method of establishing voltage-equilibrium equation and magnetic-potential equation with magnetic flux are related and compared in this paper. The consistent results indicate that the former method can be used to study not only iron-core transformer，but also non-core transformer, and therefore, is a basic analytical method.Key Words:
This paper gives the precise solution of the mathematical model for the temperature distribution of sand stone acidizing stratum under given conditions.
