ICE 2022


The Delvina gas filed in Albania consists of a series of carbonate formations from the Eocene to upper Cretaceous which are thought to serve as a reservoir and sealed by an overlying flysch. Production began in 1987 and the field has a history of producing condensate. Production has historically been lackluster largely because of challenges with the tight matrix and presence of natural fractures. Furthermore, a lack of reliable petrophysical measurements and a poor understanding of the petroleum system hampered development efforts. Recently, Energy Development Group of Albania provided funding and technical leadership with a plan to acquire lacking information and to apply modern drilling and completion techniques. Two of the key wells, Delvina 9 and 12 (D9 and D12) were never logged with modern tools. The focal point is D12, which sits at the top of the structure and has one of the best production histories. To gain actionable subsurface data for D9 and D12 legacy cuttings from the flysch to TD of both wells were analyzed with Rock Volatiles Stratigraphy (RVS) by Advanced Hydrocarbon Stratigraphy (AHS). RVS developed by AHS extracts volatile chemistries from fresh and legacy rock samples (cuttings and core). RVS of the legacy cuttings allowed for evaluating water content, resource distribution, H2S, fractures, and apparent cross field contacts in these wells that could not be re-entered. These data gave the operators a completion and targeting concept to attempt. A sidetrack of D12 (D12ST1) was drilled to provide fresh reservoir characterization and a chance to test modern completion techniques. Fresh cuttings from D12ST1 were collected and analyzed with RVS. These provided detailed information about resource concentration and composition in the present-day reservoir and detailed information about fractures, phase, and the mechanism of resource migration. In addition to providing important information that can be paired with traditional petrophysics to identify zones in the carbonate for further development, a major utility of RVS comparing the data from the legacy D12 cuttings to the D12ST1 cuttings. These comparisons allowed for a detailed appreciation of which portions of the carbonate were already drained from production, a key piece of information in the redevelopment of the field. Overall, the cuttings analysis supported a more definitive characterization of matrix, natural fractures and hydrocarbon distribution and opened a path to development.