Dan Jarvie-Petroleum Systems in the Permian Basin

Identifying different completion targets is dependent on innumerable factors, but this presentation focuses on geochemical factors. Tight oil hybrid systems such as found in the Permian basin have inter- and intra-formational targets. The source rock itself is usually a target as are juxtaposed organic-lean intervals as well as conventional reservoirs. Conventional pay zones are often overlooked or bypassed and unconventional plays were entirely bypassed until the Mitchel Energy breakthroughs in completing the Barnett Shale and subsequent application of completion and horizontal drilling technologies. While these open the door for drilling such tight oil systems, identifying the optimum zones for completion remain a challenging task. One of the key characteristics for a good return-on-investment in a tight oil play is the determination of the volatile oil window and the yield of petroleum liquids in the early gas window. While many techniques are available for maturity assessments, one of the most accurate and reproducible techniques is quantitative aromatic hydrocarbon analysis. Using this technique the determination of specific oil and gas windows may be determined such as black oil from volatile oil and condensate windows as well as the rich and lean, wet gas and dry gas windows. This technique can be utilized on rocks samples and oils so a specific correlation between rock and petroleum properties can be made when both are available.