Tight hydrocarbon reservoirs are a major unconventional reserve. To profitably develop such reserves, horizontal wells and multistage hydraulic fracturing techniques are applied to maximize the reservoir drainage areas and increase reservoir conductivity to the wellbores by creating flow channels in the tight reservoirs.

Without in-depth studies that include reservoir characterization, field modeling, well test and production data analysis by a multidisciplinary team, reservoir properties cannot be reproduced and well performance cannot be represented to accurately forecast production. Overestimating or underestimating production rates creates tremendous loss for oil companies or operators. Integrated workflow combines multiple disciplines and professionals for specific projects.

The target reservoir is in the central Jungger basin, northern China, which is a green field for tight oil reservoirs with an anticline structure, fault system and unconformity and stratigraphic traps. The paper presents the thorough reservoir characterization, systematic process and reference for a tight oil development plan. The high heterogeneity, low porosity, low permeability and production uncertainty in unconventional reservoirs sped up progress and investment in integrated workflow for reservoir development through risk quantification.

This paper presents a systematic study of unconventional resource characteristics, and describes an integrated workflow for reservoir characterization and development of tight oil reservoirs in northwest China which combines geology, seismic, geostatistics, well logging and core data. The process and methodology comprises a geological study, a field geological model with reservoir characterization, petrophysical modeling, numerical well testing, hydraulic fracture modeling based on a geomechanical study and a field reservoir simulation study. Reservoir grid is refined to capture the effect of hydraulic fracture on well performance, calibrate model using well testing and history matching for examining model accuracy, and then finally production of post-fracturing is estimated.

This paper also includes the details of sensitivity analysis proposed to address the critical uncertainties and strategy to enhance well deliverability such as well placement, half-fracture lengths, hydraulic fracturing stages and fracture conductivity.

The workflow enables the feasibility of coupling multiple disciplines including geology, geophysics, geostatistics, petrophysics and reservoir engineering into an integrated platform for information sharing, project management and strategy using static and dynamic data while simultaneously checking and updating reservoir data.

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