Optimization of hydraulic fracturing and economic analysis using production sharing contract and gross split for well-X on a naturally fractured volcanic reservoir: A case study of geothermal well Y in Indonesia.

Volcanic lithology reservoir, commonly encountered in the geothermal reservoir, is one of the harder types to be developed because of its highly varied porosity and permeability caused by the presence of natural fracture. One of the solutions to increase the productivity of this type of reservoir is called hydraulic fracturing. A simulation is conducted to model the hydraulic fracturing job, as well as its economic analysis for well-X which produced oil from the tuff volcanic reservoir. A new approach to designing hydraulic fracture is by using pseudo-three-dimensional (P3D) model. Simulation using the P3D model will give a more realistic fracture geometry compared to 2D model by also analyzing the rock layers above and below the pay zone. A sensitivity analysis is conducted by varying various parameters to achieve optimum NPV. If production sharing contract (PSC) is used, the optimum case can be achieved by using Jordan Unimin 20/40 as the selected proppant with maximum concentration up to 14 PPA, pump rate 12 bpm, and NPV for 5 years at 10% discount rate of US$ 140,370 with fracture length 69.9 feet and benefit-cost ratio (BCR) 2.23. However, if the gross split (GS) economic system is to be used, the optimum case is the original condition without hydraulic fracturing treatment, which gives NPV at 10% discount rate for 5 years of US$ 481,735. [ABSTRACT FROM AUTHOR]