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Volume 3
Journal of Environmental Chemistry and Toxicology
oil and gas
August 05-06, 2019 | Singapore
International Conference on
Oil Gas 2019
August 05-06, 2019
J Environ Chem Toxicol, Volume 3
A hybrid model for selecting horizontal candidate wells for Re-fracturing of tight oil
reservoirs - A case study in MH oil field, Junggar Basin, Western China
Rui He
Southwest Petroleum University, China
T
he tight sandstone gas reservoir in southern Songliao Basin is naturally fractured and is characterized by its low porosity
and permeability. Large-scale hydraulic fracturing is the most effective way to develop this tight gas reservoir. Quantitative
evaluation of fracability is essential for optimizing a fracturing reservoir. In this study, nine fracability-related factors,
particularly mechanical brittleness, unconfined compressive strength (UCS), mineral brittleness, cohesion, internal friction
angle (IFA), natural fracture, fracture toughness, horizontal stress difference, and fracture barrier were obtained based on a
series of petrophysical and geomechanical experiments. Taking above factors into consideration, a modified comprehensive
evaluation model is proposed based on analytic hierarchy process (AHP) method. The UCS and IFA were removed from the
AHP model based on the results of factor correlation analysis. The transfer matrix in the weighting procedure was applied
to improve the consistency of judgment matrix, and the fuzzy matrix was employed to promote the objectiveness of final
decision. The fracability evaluation of four reservoir intervals in Jinshan gas field was analyzed. Field fracturing tests were
conducted to verify the feasibility of the proposed evaluation model. Results showed that the tubing pressure curve is more
fluctuated in the reservoir interval with more developed natural fractures, and gas production is higher in the reservoir
interval with greater fracability coefficient. The field test data coincide with the results of the proposed evaluation model.
Biography
Rui He has his expertise in oil and gas reservoir stimulation mechanical and engineering technology. His fracability evaluation model
based on AHP method creates a new pathway for candidate selection in naturally fractured sandstone reservoirs. The model is
improved in many ways compared with previous similar models, and it was firstly applied in field test. The results show that the field
test data coincide with the results of the proposed evaluation model very well. His work can help reduce irrational judgments of well
selection for prioritized fracturing operation, and the engineering cost will decrease and more oil & gas may be obtained if his model
is applied more widely.
herui6868@163.comFigure 1. Hierarchy structure of analytic hierarchy process model for optimizing reservoir candidates