Analysis on economic benefits of coalbed methane drilling technologies

The coalbed methane (CBM) development activities in China are concentrated in the regions with low-permeability coal reservoirs. There are two kinds of drilling technologies: one is the conventional vertical well technology, the other is multi-branch horizontal well technology. Based on these two technologies, firstly, without taking account of the production capacity replacement and aiming at the same well-control area, the economic benefits between the development plan with whole vertical wells and the one with entire multi-branch horizontal wells were compared; and then the comparison of the economic benefits between the whole-vertical-well development plan and the mixed-well-type one was also made, considering the production capacity replacement and aiming at the same designed production capacity. IPP and NPV methods were used to calculate the economic evaluation indices of application of each plan in different CBM prospects, and the technical and economic potentialities of these two technologies were analyzed. The conventional vertical well technology can realize certain economic benefits and it is the preferred technology now, even for some time in the future; the multi-branch horizontal well technology is more suitable for low permeability coal reservoirs and can increase CBM production in these reservoirs, but the risk is high due to high drilling investment, and it cannot be popularized soon until the drilling equipment and technicians are localized gradually.