Petroleum engineering applied for coalbed methane production : likelihood in Croatia

The pore space of a coal deposit is often saturated with methane. This valuable energy source can be detected, produced and used locally as fuel and as raw material for chemical production. Coal deposits and the content of their pore space can be detected and quantitatively evaluated by well logging. If satisfactory quantity and quality of gas is established, the wellbore surrounding can be stimulated by hydraulic fracturing, by chemical stimulation or other adequate methods, as well as by horizontal or extended reach re-entry wells. In favorable reservoir conditions, daily gas production up to 5000 m 3 per well may be expected. Usually this production is economical if there are small local consumers (households, greenhouses, handicrafts etc.). Beside the use of gas as an ecologically clean energy source,the coal deposit is liberated of methane dispersed in its pores. This way, future coal production is becoming more safe. Petroleum engineering knowledge and available equipment and tools may be applied for the development of this energy source.