The Dynamic Description Of Lithologic Gas Pool During The Early Stage Of Development

During the early stage of development of LuoDai gas field,which is typical of lithologic shallow-depth gas pool, both of the static and dynamic information is scarce to describe the heterogeneous character of 3-D geologic model, so it's quite difficult to evaluate the gas pool thoroughly. The main purpose of description in the early stage of development is to make use of all those available information, for the sake of characterizing the 3-D static model ,meanwhile, sum up and analyze the dynamic character on the scale of single well and gas field , which aims to bring up the elementary development project. There are several major progresses obtained in this research as below:1. On the basis of coring data from key-well, put forward a new method to classify reservoir ,which consists of fuzzy clustering and manual filtration. Furthermore ,taking use of coring data ,a new fuzzy differentiation is used to partition the reservoir quantificationally.2. According to the research on litho-electricity correlation of reservoir ,a new kind of GA-adaptive BP neural network is brought forward to train and forecast the samples in the secondary logging interpretation of porosity ,permeability and saturation in LuoDai gas field. The result is compared with traditional BP and linear multi-variant analysis to testify that iterative speed and accuracy is much better.3. Based on the analysis of productivity and it's influencing factor ,the feasibility and procedure of interpreting the productivity after artificial fracturing by logging method is demonstrated in the first time in LuoDai gas field. The anticipation from sample training can be useful proof for the early judgment of development.4. The modern transitional pressure test is a major method to determine the reservoir parameter via dynamic information. The interpretation procedure is explained as "firstly ,model judgment; secondly, multi-segment object function; thirdly ,global optimization solution", during which a new covering complex optimization method improved by simulated annealing is introduced .At last an actual gas well is interpreted following this procedure as an example, which proves the strong robust character.5. The dynamic analysis based classification method in the early stage of development is brought forward in the first time ,which consists of:firstly ,the material balance equation and the binomial production equation is solved together for those wells with stable production., to yield the anticipation under constant production ,and constant THP afterwards; Secondly, the R/S fractal method is used to demonstrate the declining tendency for those withdegressive production, and the GM(1,1) model is adopted for simulation and anticipation. As a result ,the hard-nut in single well prediction because of deficiency of information is tackled better.6. Aiming at the complexity of tight shallow lithologic gas pool, which consists of irregular outer reservoir boundary, the fracturing of wellbore and so on , the brand new compound PEBI grid model is adopted . For the purpose of decreasing grid number and incarnate the reservoir ,the object area is divided into two parts: the near well bore area, which is described by radial grid, and the bulk area, which is described by PEBI grid. This type of compound grid is used in the simulation of LuoDai gas field to demonstrate the best recovery scheme , with the aiding of other methods.