Decline Curve Analysis of Shale Oil Production
Uppsala University, Master Thesis in Energy Systems Engineering, Linnea Lund The Case of Eagle Ford
**> An excellent well written, detailed, and concise Thesis that is
applicable to Shale Oil Production Decline Analysis.**
Not to be confused with shale oil is oil shale. Oil shale is shale rich in kerogen which is the solid pre-stage of crude oil and natural gas (International Energy Agency, 2013), and is sometimes also called kerogen shale. Liquid hydrocarbons can be extracted from the oil shale if it is heated at a controlled rate. The petroleum in the oil shale is of less quality than the shale oil, which is high quality light oil. Other resources classified as unconventional by the IEA are coal-to-liquids and gas-to-liquids.
When estimating future production (or ultimate recover) in an oil field or an oil well the concept of decline rate is fundamental. The decline rate is the reduction in production-rate from an individual field or a group of fields, after the production has peaked (Höök et al., 2014). The decline rate is defined in Equation:
Decline Rate n = ((Production n – Production n-1) / Production n-1)
where n is usually month or year, to calculate monthly or annual decline.
Also discussed are the Arps’ decline curves – “exponential” “hyperbolic” “harmonic”.
Of further interest is the Niobrara / Codell Decline Curves – Denver
Another great fact sheet is the brief article showing various decline curves for the Niobrara in the Denver Basin. The Codell will decline in a similar fashion. Companies contributing decline curves are; Noble Energy, Anadarko, PDC, Carrizo Oil and Gas, Bill Barrett Corporation, Whiting Petroleum, and Bonanza Creek Energy.
Decline curves for almost all of the US Shale Oil and Gas plays are basically similar.