Based on strategic and prospective exploration frontiers and targets, CNPC has established special investments and implemented venture exploration since 2005. After five years of discovery and practice, CNPC has made remarkable discoveries and breakthroughs in venture exploration for oil and gas in new areas and new frontiers, expanding the frontier of oil and gas exploration, deepening geologic understandings, and promoting technological progress. Meanwhile, CNPC has developed a series of effective and scientific organization and management systems and a number of effective methods in practice. CNPC's venture exploration in the past five years has played an important role in advancing its sustainable and effective development in domestic oil and gas exploration and maximizing oil and gas reserves.

The study on top boundary of sequence is very important to carbonate sequence study. The top boundary of carbonate sequence could be divided into the exposed and concordant sequence boundary and the weak exposed and concordant sequence boundary. The weak exposed and concordant sequence boundary is known as A-type sequence boundary, and the sequence is A-type sequence. The exposed and concordant sequence boundary is known as B-type sequence boundary, and the sequence is B-type sequence or AB-type sequence. Through field outcrop survey, core survey, drilling/ logging sequence analysis and comprehensive interpretation of seismic data, the sequence stratigraphic framework of Cambrian-Ordovician of Tarim Basin is established: eight sequences of Cambrian and nine sequences of Ordovician. The Tumuxiuke Formation and the Lianglitage Formation of Cambrian-Lower and Middle Ordovician and the Upper Ordovician are carbonate platform sediments, and the carbonate sequence consists of the sediments of the hemicycle of rising base level and declining base level, which divides the sequences into A-type sequence, B-type sequence and ABtype sequence.

The fault and the associated network of fracture are the main control elements of hydrocarbon pool-formation in eastern Lungu area, Where Tertiary faults developed. Fault Ⅰ consists of three discordogenic faults of Lunnan, Sangtamu and Lunnan 63, which developed in late Caledonian-early Hercynian, and has sealing process. Glide fault heading for the south and north is Fault Ⅱ, which developed in late Hercynian- Indo Chinese epoch and has tensional process. Adjoint fault heading for northeast and northwest is Fault Ⅲ, which developed amphi east and west of discordogenic fault in early Hercynian. The hydrocarbon pool-formation of Lianglitage Formation, Yijianfang Formation and Yingshan Formation of Ordovician is controlled by Fault Ⅱ and Faults Ⅲ. The fault controls the migration and distribution of oil and gas, the reservoir has the characteristics of multiple infilling, whose stage agrees with the fault movement. Filling point usually lies in the transition and intersection of the fault, oil and gas distribution presents "quasilaminar" and each layer presents "entirely hydrocarbon bearing". Locating wells along the fault is the most valid way to gain high production in Ordovician of this area.

For revealing the distribution of fractures and caves and then analyzing the effect of fracture and caves on oil and gas distribution, a comprehensive technology and method like geology, geophysics, logging and drilling are used to analyze the control of faults to fractures and the correlation of faults, fractures, and karsts. The results show that the karst development is controlled by the fault system which also promotes karst development. Fractures and karst supplement and complement each other. Fault zone is the favorable area for fracture and karst development and oil/gas distribution

Under the effect of neotectonic movement at last stage of Neogene, the whole sedimentary center of Qaidam Basin migrated from west to east, and so the Quaternary system was generated in Sanhu Area. The world's largest biogas field was discovered in the system. In the past few years, lithologicgas reservoirs have been discovered in the system, which pioneered a new field for natural gas exploration in Sanhu Area. By evaluating the basic geological background for the generation of lithologic gas reservoirs in terms of tectonic settings, gas source conditions, and source-reservoir-caprock assemblage, on the basis of simply reviewing the exploration course, this paper analyses the geological and seismic features of the lithologic reservoirs. In view of the features of lithologic reservoirs, this paper puts forward the research method for precise seismic data processing, precise isochronic stratigrahic framework correlation, and precise gas bearing test, providing technical support for further exploration study in lithologic reservoirs of the Area

Oil shale in Mujianggou Area of Ordos Basin is a set of oil shale sediments associated with coal, and the major oil shale layers are mainly distributed at the bottom of coal bed, with the thickness ranging from 1m to 2.5 m. These oil shale layers get thinner gradually from southeast to northwest, of which the burial depth gets larger. Oil shale distribution is controlled by sedimentary environment and structures. Through oil-bearing rate analysis, single-well oil shale features analysis, and oil shale outcrop survey analysis, the distribution law of oil shale in Mujianggou Area is determined. Oil shale is thicker in the low-lying area, while it is thinner or dies out in higher area. This paper also sums up the sedimentary features and models of oil shale which is distributed in the sediments of bays and lakes. Finally the resources of oil shale in the area are calculated.

Putaohua oil layers of the First Member of Yaojia Formation in Songliao Basin are large lacustrine delta sediments, and they have the characteristics of lower generation and upper storage. Oil reservoirs are mainly distributed within the range of source rocks of the central depression. The large delta complex in the north developed along the long axis of the Basin macroscopically controls the reservoir distribution. Different sedimentary facies control the distribution of the types of sand body and traps, so reservoir types present zonality on the plane. Reservoirs could hence be classified into structural reservoir, complex reservoir and lithologic reservoir. Oil and gas reservoirs controlled by high mature source rocks control concentrate in the central depressions. Oil and gas reservoir formation could be transported through unconformable surface. Oil and gas reservoirs mainly developed in the Highstand Systems Tract, while aqueous layers mainly developed in the Regressive Systems Tract.

The natural gas of western sag of Liaohe exploration area is widely distributed and the oil and gas are accompanied with each other. Hence this paper analyzes the migration, accumulation and distribution pattern of the natural gas combining with its composition and source characteristics, the exsolution features of crude oil dissolved gas and petroleum geology condition. Vertically, condensate gas reservoir, oil reservoir, gas cap reservoir, and gas reservoir are distributed from bottom to top successively at the same exploration area. Horizontally, natural gas is mainly distributed in the hydrocarbon generation sags. Dry gas is primarily distributed in the shallow part of the hydrocarbon generation sags and in the slope of neighborhood, while wet gas is distributed at different depths. Dry gas from the First Member to the Second Member of Shahejie Formation is mainly distributed in the hydrocarbon generation sags and their neighborhood, while the dry gas from the Third Member to the Fourth Member is mainly in the slope zone around the sags. The crude oil dissolved gas is the major source of natural gas accumulated in independent phase. There are four different types of natural gas reservoirforming patterns the sags with different structures. Shallow gas is rich in the effective traps over the oil reservoirs of hydrocarbon generation sags; the deep formation of the hydrocarbon generation depression and the salient around are important areas of high maturity natural gas exploration

In view of the increasing proportion of subtle reservoirs, using examples of successful domestic and overseas exploration, this paper introduces a new idea of "non-restricted exploration". Study shows that oil and gas resources assessment is a process of deepening understanding, and innovative thinking could bring new exploration results. For example, Chunguang Oilfield, a shallow high-quality reservoir, was discovered by creating the oil and gas accumulation model of western margin of the Junggar Basin; Puguang gas field was found in the old basin by innovating geological knowledge and transforming exploration strategy. Innovation of geological theory could reveal the real features of reservoir formation. For example, new reserves potential was shown in the old exploration area of Shengli Oilfield through the creation of continental rift basin subtle reservoir exploration theory; a bar and shoal reservoir was found by constructing large-scale continental rift basin shoal reservoir exploration theory. Through the innovation of engineering technology, new reserves were discovered and new progress was made in the exploration of Nanpu Oilfield, Changqing Oilfield, and Shengli Offshore Oilfield. With hard work and perseverance, new breakthroughs were achieved in the northeast slope of Shengli Oilfield and in Sangequan reservoir of Xinjiang Oilfield. The exploration practice in the deep formations of Songliao Basin and the volcanic rocks of Carboniferous in Junggar Basin is a classic instance of "nonrestricted exploration". Oil and gas exploration needs to emancipate mind, change thinking and innovate recognition. Oil and gas exploration workers are required to have the philosophers' dialectical thinking, artists' imagination, scientists' rigorous attitude, and explorers?spirit of adventure

Prediction of fluids in carbonate reservoirs is a major headache for the whole world. This paper puts forward the method applicable for predicting the fluids in the carbonate reservoir of Yijianfang Formation of Ordovician in Block A in western Tabei Uplift. This method is to predict by using the attribute of AVO fluid factors calculated from ΔvP/vP and ΔvS/vS, because the attribute response well to carbon-hydrogen. Through fluid displacement, prestack gather preprocessing, this paper obtains the attribute of AVO fluid factors using the binominal inversion method and prestack AVO inversion, and finally applies the attribute to fluid prediction, and the prediction agreement rate goes up to 85%. This lays a solid basis for the exploration of the oil and gas reservoir, and it could be good reference to carbonate exploration and development in similar blocks

The reef reservoir in Permian Changxing Formation ofWubaiti gas field has relatively low matrix porosity and permeability, but the fractures in the reservoir lead to high yield and make the permeability higher. Therefore, the key task in the research of the area is to discriminate and predict the degree of fracture development in single well by using conventional logging data. Through breaking core, the conventional log response eigenvalue of the section where fractures developed is shown. By taking the conventional log response eigenvalue as the sample, the BP neural network model based on conventional log response is established to predict the degree of fracture development in the reservoir. The total fracture density predicted by using this model matches core observation to a great extent, which proves that this model is applicable for the study area and could be used to discriminate and predict the degree of fracture development in single well in the area.

Based on deeply analyzing the application situation of exploration portfolio, this paper expounds in detail the research and application of management idea of exploration portfolio of CNOOC in recent years, emphasizing the major controlling factors and technical strategies with respect to management of exploration portfolio and the case study in selecting and optimizing the annual exploration allocation of branch companies by use of the exploration portfolio system. The results indicate that management idea of exploration portfolio plays an important role in optimizing the allocation of funds and exploration target and guiding geological evaluation, etc, and its application results come to be important scientific basis in formulating major exploration strategies and compiling exploration plan in CNOOC

Located in north-central part of Central Iran Basin, Iran Islamic Republic, Garmsar block is a Cenozoic sedimentary depression formed in the background of compression stress field. Since the Tertiary Period, influenced by collision compression in opposite directions of Elburz orogenic zone and Zagro folded zone, complicated fold-thrust faulted deformation occurred in the basin, resulting in stratigraphic uplift folds and tilting fault blocks, and forming various types of local structural traps in Garmsar Block. Qum Formation has favorable configuration conditions of source, reservoir and cap rocks, and can form self-generating and self-accumulating plays. Fault-bend folds or fault-propagation folds resulting from thrusting activities within Qum Formation can be favorable oil & gas traps. Therefore, there is certain exploration prospect in Garmsar block