Shale gas development in Sichuan Basin and its adjacent areas can be difficult to apply as same mega-scale, high density and continuous and regular pad drilling as in North America (NA) because of significantly different surface and subsurface conditions than NA. In order to speed up development of marine shale gas in Sichuan Basin and its adjacent areas with minimized learning curve, this paper introduces geoscience-to-production integration of research, engineering and operation with its associated theory, methodology and workflow. Drilling Quality is firstly established because of significant challenges to drilling technologies and engineering, long well-construction cycle, and high overall cost of well. Together with Reservoir Quality and Completion Quality which are already applied in NA’s shales, the Quality Triangle is formed to respect the uniqueness of China^’.s shale plays. This Quality Triangle forms the basis for an innovative development workflow to implement geoscience-to-production integration of research, engineering and operation. In the rapid progress of factory drilling and completion of shale gas development, it aims to dynamically optimize both efficiency and effectiveness at single well, pad, and field scales with ensured systematically and continuously optimizing technologies and solutions, and accumulating knowledge and experiences in order to ultimately enhance well productivities. This paper summarizes the implementation and success of the described such into the Zhaotong Huangjinba National Shale Gas Demonstration Project. The success proves the essential valuesand general applicability of the proposed philosophy into other adjacent shale gas projects and even other unconventional blocks. Additionally, controlling factor of high productivity of the Longmaxi shale will be discussed based on currently available data and understanding.

In Halahatang area of the Tarim Basin, the carbonate reservoirs, with maximum burial depth of over 7200 meters, are characterized by strong heterogeneity. Accordingly, it is difficult to identify and evaluate quantitatively the fractures and cavities. In this regard, a quantitative description technology for fracture-cavity carbonate reservoirs is adopted. Based on well-seismic data, beaded, flaky and chaotic seismic facies are established and their corresponding geometric structure models are built. Then, reservoir porosity model is built up with the constraint of well logging electrofacies reservoir model and seismic wave impedance. Finally, fracture-cavity space quantitative description, connectivity prediction and space description are completed. In virtue of this technology, fracture-cavity is described by quantification instead of the original attribute properties, so that prediction accuracy of heterogeneous carbonate reservoirs is obviously improved. The void leakage rate increases to 52.8% from 42%, and reservoir encountering rate increases to 91% from 82%. Obviously, this technology promotes effectively the exploration, development and production.

Turbidity of Chang 9 layer of Yanchang Formation in Zhouchang area is brought under study for the purpose to discuss the significance of regional tight oil exploration in the aspects of oil source conditions, reservoir characteristics, reservoir assemblage and expulsion pressure of hydrocarbon. The study indicates that turbidity in Zhouchang area is mainly feldspathic sandstone with development of erosion surfaces and synsedimentary deformation structures in Bouma sequence. The porosity of reservoir is 5.18 percent on average while the permeability is 0.17mD on average. It is a tight reservoir. Based on the analysis and testing, shale in Lijiapan is high-quality source rock that serves as the sufficient source for tight oil of Chang 9 layer. Meanwhile it is also an effective regional cap rock. The good reservoir-cap assemblage of turbidity sand body and Lijiapan shale structure has a certain potential for tight oil exploration. Excessive pressure from hydrocarbon pressurization in source rock of Chang 9 layer is the force to make crude oil migrate downward. It is necessary to determine the favorable tight oil exploration targets on the basis of combining hydrocarbon expulsion pressure with the good reservoir-cap assemblage.

Based on thin section analysis and X-Ray diffraction bulkrock analysis, large amount of authigenic analcite is discovered for the first time in fine-grained sedimentary rocks and tight sandstone interbeds of the Second Member of Kongdian Fromation (Ek₂) in Cangdong sag, Huanghua Depression. Under microscope, analcite is observed mainly in the form of concentrated laminations, locally as dispersed micro-crystals, and occasionally as silt to coarse sized cement, filled in inter- and intro-granular pores, as well as in fractures and liquefied veins. This occurrence of analcite suggests an early diagenetic origin. Macroscopically, it is closely related to clay minerals and the mineral contents display an interactive relationship, which indicates a non-volcanic precursor, consistent with the lack of volcanic detritus in the fine-grained deposits in this block. As an authigenic mineral precipitate under alkaline environment, its early diagenetic origin indicates that the sedimentary water body was moderately saline and alkaline. Moreover, its early precipitation could inhibit compaction and partially preserve pore spaces, and in deeper burial diagenesis, secondary pores are fromed due to local dissolution of analcite when react with organic acid. In this way, analcite plays an important role in improving properties of tight reservoirs.

Tight sandstone oil is distributed in Gaotaizi and Fuyu oil reservoirs in the central depression in northern Songliao Basin, with accumulative resources more than 10×10⁸t. Based on exploration practices, the tight reservoirs are characterized by heterogeneity (vertically unconcentrated, laterally discontinuous, small single sand body, and variable physical properties), so they can not be developed effectively by using conventional techniques. As for heterogeneous characteristics of tight reservoirs in Daqing Oilfield, integrated technical research has been conducted since 2011 in three aspects of fine resource confirmation, horizontal well productivity increase and effective development. A series of tight oil exploration technologies have been developed, with fine resource assessment, fine sweet spot description and fine horizontal well trajectory control and oil reservoir stimulation as the representatives. Moreover, low-cost, high-efficiency factory mode has been formed for purpose of "effective development". It is shown by several years^’ practical exploration that the average oil reservoir encountering rate of horizontal wells remains above 75% and its average daily oil production at the early stage after fracturing is 30t/d, which is 17 times of its neighboring vertical wells. Three test areas are founded, with cumulative oil production more than 7 ×10⁴t and additional 3P reserves more than 2×10⁸t.

In the 1990s, oil and gas exploration in the middle section of Shijiutuo Salient, Bohai Sea area, focused primarily on structural reservoirs and secondarily on lithologic reservoirs. Over a decade of exploration, however, no breakthrough progress was made in this area. Accordingly, exploration targets were changed to lithologic reservoirs at structural flanks, which have revealed good results. Through the practices of lithologic reservoirs, a set of exploration approach and techniques have been concluded for the middle section of Shijiutuo Salient. In detail, based on integrated exploration and development, sequence stratigraphy framework of target layers is established by using sequence stratigraphic classification technique, and key geophysical technologies (e.g. fine time-depth conversion, formation slice, combined seismic attribute analysis and integrated reservoirs prediction) are combined, in order to realize great progress in the exploration of lithologic in the area. Application has proved good results, with the success rate of drilling up to 80%.

In order to improve the gelling behaviors of organic clay in mineral oil with low aromatic hydrocarbon content, several rheology modifiers are developed with different functional groups. A series of experiments are performed on mineral oil based drilling fluids to identify their general properties, low-shear rate viscosity, linear viscoelasticity and high temperature/high pressure rheology. It is shown that the mineral oil based drilling fluids containing rheology modifiers (e.g. polyester amide (BZ-ORM-Ⅰ), polyamidoamine (BZ-ORM-Ⅱ) and alkanolamine (BZ-ORM-Ⅲ)) present higher low-shear rate viscosity when the density is 1.30 g/cm³. The viscosities corresponding to shear rate of 1.7s^-1 and 0.17s^-1 meet the requirements of the ^“dynamic settling window^” theory and elastic modulus G^′is higher than viscous modulus G^″. An obvious synergistic effect occurs between polyamide amine and alkanolamine rheology modifiers, and yield values are higher in the situations of high temperature and high pressure or low shear rate. The rheology modifiers containing amide, amine and akloxy together are mainly used to realize excellent suspension properties and remain weak progressive gelling behaviors of mineral oil based drilling fluids by modifying their gelling structures.

In the past five years, a number of giant gas fields have been discovered in offshore East Africa. They are mainly located in Ruvuma and Tanzania Basins, with total recoverable reserves of 3.8?0¹² m³. It is indicated by regional tectonic evolution study and basin structure-sedimentation characteristics analysis that the basins in East Africa mainly experienced three phases of structural-sedimentary evolution, including: (1) Karoo rift period of Late Carboniferous to Early Jurassic, with dominant sedimentary facies of fluvial, lacustrine and delta; (2) Madagascar rift period of Middle Jurassic to Early Cretaceous, with dominantly continental and shallow marine facies, the principal source rocks developed; and (3) Madagascar drift period of Late Cretaceous to Quaternary, with dominantly passive continental margin sedimentation, with turbidite sandstones of abyssal fan, slope fan and gravity flow channel as major reservoirs and the shales as regional cap rocks. Major plays of the giant gas fields are Oligocene-Pliocene, Paleocene-Eocene sandstones in the Ruvuma Basin, and Oligocene and Upper Cretaceous sandstones in the Tanzania Basin. In Ruvuma Basin, the giant gas fields are mainly located at deep-water thrust belts and their fronts. Thrust belts are widely developed at Ruvuma front due to gravity collapse and Jurassic salt diaper, and they act as good migration pathways for oil and gas. Oil and gas migrates upwards from the deep source rocks and accumulates in sandstone reservoirs of thrust belts. In Tanzania Basin, giant gas fields are mainly located at the gravity flow channel sandstones of slopes, and oil and gas accumulation is controlled by the S-N normal faults.

Guided by the basic theories of sequential stratigraphy and sedimentology, the study is made of Cretaceous sequential stratigraphy and sedimentary system in Termit Basin of West Africa for the purpose to determine target stratum series and areas in the next exploration stage. The study indicates that the Cretaceous system in Termit Basin can be divided into two secondary sequences, 10 tertiary sequences and 28 quaternary sequential units. TS1 sequential sedimentation of the Early Cretaceous was controlled by fractural activities and filled mainly in the pattern of fault-controlled steep slope to fault-controlled gentle slope. TS2 sequential sedimentation of the Late Cretaceous came under the influence of the Tethys Ocean and South Atlantic transgression. The sedimentary paleao-environment experienced “land-ocean-land” development. The sedimentation was filled mainly in the pattern of flexure slope break and sedimentary slope break. Material sources are located mainly in the eastern part of Termit Basin, where, sedimentary systems of various types developed, such as fan delta, braided river delta, near shore subaqueous fan, far shore subaqueous fan and littoral-neritic sea. Controlled by provenance and sedimentary facies, vertically, DSQ1 and DSQ2 low-level system domain and YSQ1 and YSQ2 high-level system domain have good conditions for reservoir-cap assemblage and are the targets for exploration of the Cretaceous System. On the plane, successive development of positive structural zones like Fana low uplift and Yogou slope are the favorable zones of oil and gas migration and accumulation, which are the targets for next-stage exploration.