In view of the problems of the strong heterogeneity in the formation of Z15 well field in western Tazhong，the buried depth of the main formation of interest over 5 000 meters，the bad quality of seismic data，and minor faults to be difficult to identify，and so on，we present the discrimination method for the minor fault interpretation to be easy to implement. Namely，amplitude on top of the Cambrian salt bed，twist on top of limestone bed，paternoster in the seismic section，and facies change of seismic lineup in carbonate inside. By these methods，the faults are described accurately in plane and section. The west-east direction overriding fault developed in middle and late Caledonian and transtension strike-slip fault developed in late Caledonian and early Hercynian is the main faults system in Z15 well field and controlling the distribution of formation and reservoir. Several wells drilled through fault in this well field prove that the fault and fracture developing area are favorable for high production well. Fault and fracture developing area are good to be drilled because of its well-developed formation，well conserved hydrocarbon and weak aquifer energy in Lianglitage group. This will break new ground for researches formation and reservoir related to fault. And it will also help to discover new oil and gas concentration area.
Now，many of the prediction methods of development indexes are suitable for the middle-high permeability oilfield， which does not consider the effect of the starting pressure. In this paper，based on the model of the multilayered non-piston water flooding reservoirs，and considering the impact of the starting pressure，he calculating method of the development indexes in the constant flowrate production was derived. During commingling production，each layer of different permeability has different production pressure drop and low permeability layer shows bad fluid supply capacity due to the effect of starting pressure. A set of predicting method for constant flowrate production which can reflect the objective reality have been derived and verified with field examples. Results show that，due to the change of water and oil seepage resistance in commingling production， the production pressure drop decrease gradually，and the fluid production ratio of high permeability layer is increasingly greater，which intensifies interlayer interference. This method reflects accurately the characteristics of reservoir production. The feasibility of the method is confirmed theoretically and practically.
A new generalized water drive curve proposed by Tong Xianzhang is of simple shape，and reflects different laws of water cut and it is easy to obtain its parameters. This water driving curve has played an important role in predicting oil production and recoverable reserves. On this basis，further studies were made and improved beta-water drive curves were derived according to the two-phase seepage theory. The improved water drive curves show that seepage characteristic determined the water drive curves. By using the improved water drive characteristic formula more accurate results can be obtained in geological reserves calculation. The improve water drive curve provides a new method for more accurate water-flooding reserves calculation in high water cut stage and has important practical significance to mine production pratice.
view of the fact that the gas of the stripped wells has not been developed, this paper presents a preliminary sibility plan of its development and utilization by adopting the techniques of solid desulfurizing agent(SDA), ssureswing absorption (PSA), absorption natural gas (ANG) and natural gas vehicle (NGV). Through lysis, evaluation and comparison, it is considered practical and feasible to store and transport the gas in steel inders after it is purged and absorbed by a skid-mounted gas purification plant. The gas can be used fuel for icles and in daily life, and as a fuel of vehicles, it has great benefiits in economy, society, and environmental tection.
In view of the high investment and risk and uncertainties in drilling operation，the safety evaluation about the drilling operation is carried out in the paper. The method of evaluating risk and seeking risk resource during drilling operation has been developed by using Bayes network. The 32 risk factors during the drilling operation could be classified into manmade risk factors and natural risk factors by analyzing the history data and identifying the dangerous factors with the help of expertise. The Bayes network topological structure and conditional probability table（CPT）was developed for drilling operation risk；the probability was predicted forward and diagnosed backward；the safety probability of drilling operation was evaluated quantitative and the most dangerous factor was found out. After applying the Bayes network model to Well L gas drilling operation，we got the risk probability of man-made risk and natural risk at 0.108 and 0.165，respectively，the risk probability of Well L gas drilling operation at 0.137. The many dangerous factors are defects in monitor during the drilling process，lack of security protection facilities，hidden trouble induced by drilling operation，defect in well-control equipment and management in production. This will provide precise diagnostic data for operators and decision-making for safe production.
