This paper presents two methods for easy determination of water influx in reservoirs based on the material balancetheory of reservoirs, i.e., the Net Production Volume Curve, and the Production Index Curve. These methods can be used for esti-mation of water influx in reservoirs without any assumption of aquifer shape and size by applying the production performancedata. Hence the tedium of the conventional trial-and-eror calculations and obvious uncertainty could be overcome in applicationof the easy and practical new methods.

Low permeability tight gas reservoirs and condensate gas reservoirs account for a rather high proportion odomestic gas reserves, but many of them have low productivity. So it is significant to develop these reservoirs effi-ciently for continuous and stable development of China's petroleum industry. Around the problems of the developmentof deep low permeability tight gas reservoirs and condensate gas reservoirs, this paper makes an analysis on the geo-logic and development characteristics of these reservoirs and presents ten proper technologies. Finally, five technicalmeasures for the development of such gas reservoirs are proposed in detail. These are deep fracturing technology,treatment technology of accumulated liquids in condensate gas well and near well bore, gas injection technology whenthe formation pressure is lower than the maximum condensatepressure, phase behavior analysis technology in porousmedia of low permeability tight condensate gas reservoir and other gas reservoir engineering technologies.

Since the period of the Eighth Five-Year Plan, important breakthrough has been made for petroleum exploration in western China. A number of high-yield large and medium-sized oil and gas fields were discovered in basins such as Junggar, Tarim, Turpan-Hami and Shaanxi-Gansu-Ningxia etc.. so were done around seabeach area of Bohai bay. These achievements benifit by proper implementation of the strategies in China’s petroleum industry “to maintain the production in the east and develop the resource in the west" as well as devoting major efforts to developing new and advanced technologies on petroleum exploration. In order to keep these situations continuously, it is necessary to strengthen exploration in the western areas during the period of the Ninth Five-Year Plan, along with making new prospecting in the eastern area, developing new and advanced exploration techniques, increasing exploratory investment of the west to reach 30% of the total amount in China's petroleum industry, and intensifying and improving management structures in petroleum exploration.

Low permeability tight gas reservoirs and condensate gas reservoirs account for a rather high proportion odomestic gas reserves, but many of them have low productivity. So it is significant to develop these reservoirs effi-ciently for continuous and stable development of China's petroleum industry. Around the problems of the developmentof deep low permeability tight gas reservoirs and condensate gas reservoirs, this paper makes an analysis on the geo-logic and development characteristics of these reservoirs and presents ten proper technologies. Finally, five technicalmeasures for the development of such gas reservoirs are proposed in detail. These are deep fracturing technology,treatment technology of accumulated liquids in condensate gas well and near well bore, gas injection technology whenthe formation pressure is lower than the maximum condensatepressure, phase behavior analysis technology in porousmedia of low permeability tight condensate gas reservoir and other gas reservoir engineering technologies.

System tracl, a basic unit of T-gradc sequence, is a combinalion of the sarme-termm depositional systems controlled by water level changes (lacustrine level or sea level). Petroleum tends to being accumulated in the depositional sand bodies of differ-ent syslem tracts. The lype and distribution of lithologic pools could be predicted by characlerization of systeni tracts and analysis of depositional systems. In southwestern Qaidam basin, the characterization of system tracls shows that there exist developed transgressive system tract (TST) and various types of reservoirs 8uch as sand body of deltaic front, lacustrine beach and dam as. well as local turbidite of semideep lake. Based on synthetically geologic and seismic analyses, using digital seismic processing techniques (Jason's reservoir inversion, etc.), the sand body dislribution could be described, hence predicting that in southwest-ern Qaidam basin mainly developed the lithologic pools of SB, TU, DT and SS types.

China-type petroleum domains include onshore China and adjacent belts,which is enwrapped by Asia-type petroleum domain. Such small, intensively active continental nucleus did not generate a unified platform by continental overgrowth until the end of the Paleozoic, and was separated by the subducted and closed Tethys Sea during Mesozoic and Neozoic period, resulting in the most complex tectonic features in the world. Within the petroleum domains, the hydrocarbon-bearing Paleozoic, Mesozoic and Neozoic sequences were superimposed in a basin. With an exception of the active continental margin basins, the intra-cratonic basins had disappeared, and the foreland basins and rift basins were different from others in the world, so they can be called China-type basins.

A bstract: The right-slip Talas-Ferganhna fault plays significant roles in controlling the strata, structures and petroleum geologic features in Kashi sag since Late Triassic. During the Late Triassic-Middle Jurassc,Kuzgongsu and Kezletao fault basins probably disconnected with each other occurred in the sag, with developed rifted-style source rocks of Lower-Middle Jurassic. During the Neogene-Quatemary, the relevant strike-slip deformation of the fault occurred and controlled the petroleum traps and accumulations in Kashi sag.