China’s onshore oil/gas exploration domain has been changing a lot in the past decade. Before the advancement of “sag-wide oilbearing” theory, “secondary tectonic belt” was the major domain of exploration. After that, the domain has been transferred to hydrocarbon rich depressions. Besides, breakthrough has been made in high mature and overmature strata of deep superimposed basins, based on the theory of “successive generation of natural gas from organic materials”. So high mature and overmature strata became the major substitute area of reserves growth in the future. Future onshore oil and gas detection will lay equal stress on the structural reservoirs and lithologic stratigraphic reservoirs, the deep and mid-shallow layers, and the conventional and unconventional oil/ gas resources. Sustained innovation of oil/gas accumulation theory and steady progress of engineering technology will still be the key to realizing stable growth of oil/gas reserves

Faults developed in all troughs in Huanghua Depression, and there are many types of structures in deep buried hills. Moreover, two sets of source rocks from the Second to the third member of Shahejie Formation or Carboniferous-Permian have higher thermal evolution degree and good reservoiring conditions. The Lower Paleozoic reservoir rocks are affected by three factors as the buried-hill overlying strata distribution range and different denudation degree, the faults development degree, and the underfl ow zone development degree. Also carbonate palaeokarst developed in some deeply buried hills. So deeply buried hills in Lower Paleozoic are favorable for hydrocarbon accumulation. Especially, there are fi ve factors favorable for reservoiring, that is, the earlier hydrocarbon charge stages, the smaller migration distance, the multi phases of oil/gas trapping, the great amount of gas in the deep and lower demand for accumulation conditions, and the superior oil/gas preservation conditions in later stage. However, the key factor of oil/gas enrichment in the area depends on the presence or growth degree of “oil-supplying” window. Two deeply buried hill structures of Nandagang and Gangdong are the major targets of oil and gas exploration, but the key problems to be solved are: there is an oil-supplying window in Lower Paleozoic carbonate strata in Nandagang fault and one side of Qibei fault or not; whether the traps in Ordovician buried hills are fulfi lled or not.

To the complicated petroleum exploration targets, seismic exploration technique is not only a technical problem, but also an economic one. On the one hand, advanced geophysical techniques are needed for complicated geological problems; on the other hand, advanced techniques always demand for high cost. So how to choose both advanced and economic techniques should use the principle of technical economics, choose economic and practical techniques according to specifi c exploration targets, and maximize economic returns of exploration. Technique dominates the seismic exploration cost constitution. Targeted choosing of techniques and methods and fulfilling technical and economic integration according to surface conditions and geologic features are the main strategy for selecting seismic exploration techniques. Technically binning (or group interval), coverage, array length, and near-surface survey density are key parameters infl uencing data quality. To acquire high-quality data for geologic target exploration must be based on different surface conditions and different subsurface geologic conditions to select key technical parameters. The change of key technical parameters certainly brings about change of equipment and staff input as well as construction organization. Therefore, it directly affects the change of investment and cost. This paper discussed the technique optimization principle aimed at different surface conditions and different geologic targets. To realize technical and economic integration should be based on technique optimization taking both technical advancement and applicability into account.

Whether there is drilling failure in oil/gas exploration is a controversial topic. This paper preliminarily defi nes successful well and failed well from different aspects and different angles of oil/gas exploration. Currently well location arrangement of oil/gas exploration and development is mainly based on seismic exploration results. Seismic exploration is a predicative science, and it is normal that there are both success and failure in well arrangement. Anticline trap is the major target of mountainous seismic exploration. Seismic exploration consists of three aspects, i.e. acquisition, processing and interpretation, and deviation in each aspect may result in drilling failure. Poor quality of acquired data may lead to multiple solutions of processing and interpretation, thus causing lower precision of seismic results. Improper processing parameters may result in false structural appearance and mislead interpreters to make wrong decisions. Complex mountainous structure interpretation may cause deviation of horizon calibration, structural modeling and velocity fi eld, resulting in well-to-seismic incoincidence. Analysis on drilling failure means that interpreters timely acquire geologic and log data of drilled wells, use seismic techniques to confi rm or correct original results, then carry out corresponding seismic exploration techniques and measures to acquire new seismic results, timely guide drilling work of next step, and maximize oil/gas exploration benefi t.

In Gaoyou sag of Jiangsu Oilfi eld, seismic data quality is infl uenced by structural factors, such as structure crushing and complex fi eld surface conditions, and the thickness of target sand bodies is often less than the vertical seismic resolution. So single sand body cannot be directly identifi ed from seismic section, and it is very diffi cult to improve reservoir prediction accuracy using existing seismic data. Through the analysis of geological background in Gaoyou sag and the high resolution sequence stratigraphy research, the analysis of sedimentary background, sedimentary sand body development and sand control mechanism research of Dainan Formation, the integrated use of geological, well logging, drilling and seismic data, a set of fault-lithologic reservoir exploration method is established: according to the qualitative and semi-quantitative and quantitative reservoir prediction, use prestack seismic inversion, AVO forward modeling and seismic attribute analysis technology to determine sand body development area, carry out quantitative reservoir thickness forecast, finally integrate qualitative and quantitative research results to improve reservoir prediction accuracy, and provide favorable drilling targets. High success rate proves that the method is effective in fault-lithologic reservoir exploration.

Overseas risk exploration projects are faced with the threats of geological conditions, political situation, fi nance and taxation items and so on in the running process, resulting in the limit of incertitude factors and self-experience as for the management, and the exploration decision is normally difficult to make and the operation methods may be improper, associated with the pressure of HSE and the problem of staff instability. Aiming at these problems, project managers should make appropriate exploration decisions from the angle of full risk management, and establish scientifi c and systematic evaluation system and response system by understanding the internal relationship among different risk factors. Overseas exploration projects are confronted with uncertainty factors such as space, time, budget, goal and task and so on in terms of management control, so they need to be constantly adjusted and optimized in terms of decisions and strategies in line with external factors. Domestic oil enterprises should continue to improve the quality of personnel, make efforts to improve the level of bidding, decision demonstration, and HSE management to be in line with international standards. By improving the technical strength and management level to maximize economic benefi ts of overseas exploration, it will precipitate overseas exploration to develop effi ciently and scientifi cally

South Asia underwent three stages including Gondwana intercontinental rifting, Gondwana passive margin after continental breakup and collision between Indian plate and Eurasian plate and formed four types of basin that is peripheral foreland basin, passive continental margin basin, continental rift basin and cratonic basin. Petroliferous basins concentrate along the eastern and western margin of Indian continent with good petroleum geology. Oil and gas accumulates in the Paleogene, Neogene and Cretaceous. Scale and horizon of oil/gas reserves are determined by basin type and evolution. Horizontal hydrocarbon distribution is controlled by distribution of effective source rocks. Vertical hydrocarbon distribution is controlled by reservoir-cap rock assemblage. Based on comprehensive evaluation by indices such as basin type and scale, petroleum geology, resource quantity and exploratory degree, Bombay Basin, Indus Basin, Krishna-Godavari Basin, Bengal Basin, Assam Basin, Cambay Basin, Cauvery Basin, and Potwar Basin are optimized as favorable ones for hydrocarbon exploration in South Asia

Salawati Basin is located in the Bird Head region of eastern Indonesia. It is an important petroliferous basin in Indonesia. Based on the study of regional geological data, combined with seismic and log data as well as oil/gas fi eld data, the characteristics of petroleum geology and oil/gas distribution as well as main factors of hydrocarbon accumulation were researched. It showed that Salawati Basin underwent three stages as the early rifted stage, the middle compressional sag stage and the late compressional folding including local thrust stage. The source of Salawati Basin is the marine shale of Klasafet Formation in Miocene and the reservoir is the carbonate reef of the Kais Formation in Miocene. The Kais Formation underwent three stages and the platform carbonate developed in the fi rst stage is the good oil and gas migration path. Three fairways exist in Salawati Basin. The distribution of oil and gas fi elds is controlled by hydrocarbon differential accumulation. It features in gas inside and oil outside on the plane. The key factor of hydrocarbon accumulation is the NW-SE trend of structural nose dipped into the kitchen in the northwest of the Basin. Meanwhile, the KOI area located in the structural nose is the future exploration target

Based on the data of IHS2009, combining the results of previous studies, the stratigraphic features of Huqf Group from Precambrian to Early Cambrian in Oman Basin is analyzed in detail. The study shows that the strata of Huqf Group are the products of basin development from early rift to depression. Sedimentary environment which includes shallow sea, intermittent sea and intertidal-supralittoral zone is developed during this period. It is an important oil and gas stratum in this basin. The dolostone of Khufai member in Nafun Formation and evaporive of Ara Formation are important hydrocarbon source rocks. The dolostone of Buah member and biological rock of Ara Formations are the main reservoir. Obviously, oil and gas accumulation and distribution of Huqf Group in Oman Basin are controlled by structure evolution and sedimentary facies distribution. The main migration path of oil and gas is fracture and regional unconformity of the bottom of Ara Formation