According to the geologic theory of paleokarst and Carbonate reservoir-forming,the geologic background of natural gas reservoirs formation and accumulation in marine carbonate rock and the basic features of unconventional large subtle paleokarst gas reservoir in Ordos Basin, which include source rock, reservoir, cap rock, trap, migration and accumulation law, are analyzed systematically. And it is put forward that marine carbonate rock reservoir and trap in stable platform are the key factors. Starting From this point, it is studied the cause of paleokarst formation and developed features of paleokarst landform, and revealed the mechanism and distributing law of the network formed by pores, caves and fissure in weathering crust. Through setting up the model of paleokarst landform and applying it in practice, the achievement of natural gas exploration for paleo-weathering crust has been continuously made

There are quite plenty of natural gas resources and huge potential for exploration in Junggar Basin. The basin possesses the favorable geologic conditions to form large natural gas province. There are three sets of source rocks such as Carboniferous, Permian and Jurassic, which have high evolution degree, so gas source condition is plenteous. Multiple and multilayer reservoirs and four regional covering strata upgrowth so that they form advantageous reservoir-cover combination and configuration of gas pools forming. By research of typical gas reservoirs distributed in Wucaiwan, Dixi, Mosuowan and Mobei areas, various types of gas reservoirs, including structural type, paleo-burial-hill type, volcanic inner-episode type and stratigraphic unconformity screened type, are developed in this basin. On the basis of study, it is pointed out that one practical domain, i.e. Ludong-Wucaiwan, Luxi-Mobei-Mosuowan areas; two breakthrough fields, which might be the large-scale structural traps in lower assemblage of the central basin and the foreland thrust belt of southern margin in Junggar Basin, should be broken and one preparative realm for exploring gas-coalbed methane exploration should be rapidly prepared to makeup or to supersede routine gas resources

The amount of oil resources of 8587million tons has been discovered in Junggar Basin .It took 50 years for oil exploration , but the discovery rate of oil resources in the basin reaches only 21.85% up to the present. Comparing with the mature basins in eastern China (60% in average) and the major petroliferous basins in the world (77.1% in average), Junggar basin assumes a lower level in oil resource discovery rate. So an additional 3200 million tons of discovered oil geologic reserves is at least to be proven in this basin. It presents the analyses of growth tendency of domestic oil reserves, the relationship between the proven degree and the discovered speed of basinal resources and the incremental patterns of proven reserves in Junggar Basin in the Seventh Five-Year Plan to the Tenth Five- Year Plan period, provides the predicted indices of the oil reserves, and makes predictions of the future growth patterns of proven reserves in this basin. The result shows that the incremental proven reserves in Junggar basin will be at the level of 68.59 -96.69 million tons during the Eleventh Five-Year Plan period, the discovered speed per year will be 0.80%~1.12%. In 2011~2020, the annual incremental proven reserves should range from 63.90 to 96.90 million tons with annual discovered speed of 0.74%~1.13%. According to the status and efforts for petroleum exploration nowadays, the petroleum geologic conditions and the hydrocarbon accumulation characteristics, as well as the hydrocarbon migration/accumulation regularities and the exploration potentials in Junggar Basin, it is believed that the majority of reserves to be proven will be found in new areas or domains with low discovered rate in Junggar Basin one after another.

Junggar Basin is abundant in natural gas resources, but the exploration degree of its resources is very low, which is only 3.48%, far under the average level of the whole country and all basins in western China, these indicate that enormous exploration potentiality in this basin. The break-through of natural gas exploration and fast growth of the reserves are the key and important guarantee that Xinjiang Oilfield Company will realize sustainable development. By analysis,author believed that the main target of natural gas exploration in the basin is to look for the large-medium gasfields. The abdomen and the south margin of the basin is favorable area to form the high-temperature pyrolysis gas reservoir and coal-type gas reservoir. On the basis of this research, risk analysis for natural gas exploration have carried on various areas in Junggar Basin, and guiding suggestions and measures on how to break through natural gas exploration and ensure fast growth of natural gas reserves in the future are proposed.

With the guiding of the theory of subtle oil/gas reservoirs exploration, Daqingzi and Yingtai oilfields with the reserves of hundred million tons in southern Songliao Basin have been discovered successively. Through study on the geological condition, the lithologic oil reservoirs is characterized by "three-low" oil layer, which include low porosity, low permeability and low oil-bearing saturation; in plan view, it can be seen the large changes that the good connectivity between oil reservoirs along the direction of material sources, whereas not good connectivity between them in transverse source direction; the distribution of oil and water are mainly controlled by depositional facies belts, and the petroliferous property is also mainly controlled by rocks and physical property. Aiming at the problems covering thin-mutual oil layer identification, low production of "three-low" oil layer as well as complex oil -water relation, in lithologic reservoirs distributed in southern Songliao Basin , technical research works has been initiated, gradually developing a series of techniques, such as reservoir identification and appraisal, complex oil-water layer identification and "three-low" oil layer production increment, providing technique safeguards for the full-scale lithologic reservoir exploration

Based on analysis of the conditions of pool-forming and their space-matching relationship of Gucheng oilfield in Biyang Sag, the pool-forming stages are determined by using fluid inclusion technique, combined with the results of hydrocarbon generation simulation, fine oil-source correlation and tectonic evolution history, the styles of oil migration & charging and the processes of pool-charging are discussed in detail. The above results indicate that there exist three stages of oil charging: (1) In the first stage of oil charging, the large amount of low-mature oil-gas generated from the upper part of first member of Eogene Hetaoyuan Formation, slowly poured toward to Gucheng nose tectonic, and formed a certain oil-gas reservoirs;(2) In the second stage during Early Himalayan, the tectonic activity resulted in uplifting and erosion of regional strata and faults activity, meanwhile destroyed the paleo-reservoirs and oil full-charged largely and rapidly ,which generated from the upper part of third member of Hetaoyuan Formation, so drove and replaced oil/gas generated from the lower part of third member of Hetaoyuan Formation, finally formed lots of fault-block and fault-nose reservoirs, laid a foundation for the distribution framework of present Gucheng oilfield;(3) In the third stage during Later Himalayan, new tectonic movements resulted in the adjustment of oil/gas reservoirs formed in the first and second pool-forming stages, and made a few high-mature oil/gas recharge and formed present Gucheng oilfield.

After developing and growing for several decades, PetroChina holds more than 150 crews covering the geophysical technique service, their annual acquisition capacity reaches 2D 100 thousand km, 3D near 40 thousand sq.km ,ranked the first in the world, and meanwhile posses a staff of seismic data processing and interpretation with perfect skill. Up to now, the company has formed a series of dominant geophysical techniques including 6 acquisition, 6 data processing and 11 data interpretation,and have been developing 3 acquisition-processing techniques focusing on complicated region, and actively tracking 3 preceding geophysical techniques. However, the objects that oil/gas exploration of PetroChina are faced with might be more and more complicated, and the quality request for seismic data will be needed to raise gradually with the exploration degree upgrading, through developing continuously the seismic exploration technique and generating the series matching technique with special features , tackling key bottleneck technique and tracking the development of forward technique ,PetroChina will be boosted to realize its maximum benefits in oil/gas exploration and development

Basin modeling has developed for nearly 30 years. Up to now, basin modeling systems cover 1D, 2D and 3D model. They not only include conventional "five histories", i.e. geohistory, geothermal history, hydrocarbon generation history, expulsion history and accumulation history, but also increase several unconventional studied contents. By analyzing and summarizing abundant related technology information, it shows that basin modeling technology is developing forward to systematization and specialization. Through the application in the recent round national petroleum resource assessment of China, it was proved once again that basin modeling technology had been developing and becoming more and more perfect, so it played an important role: Firstly, it promoted the standardization of base geological parameters so that they were more reliable; Secondly, it made the amount of hydrocarbon generation and expulsion be more accurate, through restoring the effective source rocks zone, introducing effective ratio of hydrocarbon expulsion, and by rectifying the amount of cracked gas; Finally, integrating results of statistical multianalysis, more accurately resource amount and its distribution were predicted

On the basis of summing up the setting background of programming during the 10th Five-Year Plan and its features in Daqing Oilfield , after the implementation of this program has been analyzed, it is concluded that the program witnesses the guidance, rationality and science technology, and liberating of the exploration concept is crucial to oil/gas discovery breakthrough, and the adjustment of exploration concept has been laid the foundation to oil/gas discovery as well as the implementation of "five increase" engineering (i.e. increase investment in integrated research, seismic engineering ,3D acquisition, pre-prospecting drilling and advanced technology) has ensured to realize the breakthrough of oil/gas discovery. During the 10th Five-Year Plan period, notable results has been achieved in Daqing region, including deeply understanding the reservoir-forming law of lower assemblage of lithologic reservoirs in syncline area, the controlled oil geologic reserves and the predicted oil geologic reserves accounted for 64.3% and 74.8% of the total respectively in the same period; the discovery of Qingshen gasfield is milestone of deep natural gas exploration in northern Songliao Basin, giving the prominent increase of natural gas reserves in this area; realizing the commercial development of Hailaer basin in this period.

The value appraisal,a kind of economic appraisal method, can be used to evaluate the market value and business effects of the enterprise and its internal businessmechanism , production and business activity, economic appraisal ofmedium and long term development plan as well as a mass of fiancial affairs indices. By comparative analysis between appraisal index and practical index, consequently optimize the plan project, analyze the enterprise's business effects and improve the enterprise's business management level. Aiming at the oilfield planning and the reasonable allocation and effective use of the resources, it is suggested that reasonable investment frame, implementation degree of production capacity construction and unit investing effect are key factors to affect the return ratio of investment; oil price and output are main factors to restrict oilfield planning effect

Due to the status of the quota of exploration engineering lagging behind the technique development of exploration engineering and rating arrangement system being under disorder, the management of exploration engineering costing should get out of the error concept that regarded the quota as pricing, and as only one factor of investment control , resume theòneuteró nature of quota and set up the quota according to its essence requirement in order to enhance the quota's foundation. Beyond the disputing on related òbenefitsó, the quota can be brought into the consumption standard system, so the investment control should be limited by means of the total gross control and benefit index restricting

Based on detailed analysis of the feature of coalbed methane (CBM) reservoir in Yangjiaping CBM test region, it summarizes and appraises CBM basic geology, coal petrology features, gas-bearing content, adsorption\desorption capacity and reservoir porepermeable capacity in coal seam. It provides basic test and analysis data. This research indicates that the CBM basic geologic condition in Yangjiaping CBM test region is favorable, every reservoir parameter is advantageous, beneficial to CBM development.

By analysis of enrichment law of coalbed methane in Powder River Basin in USA and Tiefa Basin in China, it summarizes that the plug-backing is the key factor to affect the enrichment of lower-rank coalbed methane, the main factors to form plug-backing of coalbed methane include tectonics, rocks and water momentum. Meanwhile, it is put forward that 5 various modes of coalbed methane enrichment, including anticline mode, structure-water momentum, structure-lithologic mode, lithologic-water momentum mode and lithologic mode

Oilsand has been found in many ground structures in northern Kashi sag, which distributed mainly in Miocene Anjuan and Pakabulake Formation, secondly in Lower Cretaceous Kzlesu Formation.The axis and two limbs of anticline are favorable for oilsand distribution where have well-developed faults. The oil-bearing content of oilsand is close to rock lithology, and therefore high oil content occur mainly in fine-grained sandstone and fine-median grained sandstone. The oil source of oilsand in northern Kashi sag came from Jurassic hydrocarbon source whose reservoir-forming stage might be from Miocene to Pliocene. Early oil reservoir had been destroyed by the tectogenesis in Later Pliocene, and forming oilsand on the surface occurrence in northern Kashi sag

Asymmetrically alternant movement of half-horst in Muglad Basin is accomplished by accommodation zone. By analyzing types, structure styles and distributing characteristics of accommodation zone in Muglad Basin, it indicates that accommodation zone is a long and continuous inherited developed structure, which always controls the distribution of sandbody and is adjacent to oil-generating sag which is a favorable zone for oil/gas migration and a favorable target for oil/gas exploration. In recent years, several significant discoveries have been made in this basin related to accommodation zone and certain size of profit reserves have also been found continuously. There is a favorable prospect in accommodation zone of Muglad Basin.