Advanced Cuttings Analysis Provides Enhanced Support for Geosteering in Underbalanced Coiled Tubing Drilling
A.F. Marsala and G. Oliver
Event name: 80th EAGE Conference and Exhibition 2018
Session: Poster: EOR C
Publication date: 11 June 2018
Info: Extended abstract, PDF ( 1.57Mb )
Price: € 20
Underbalanced Coiled Tubing Drilling (UBCTD) is proving more promising in the industry, helping to unlock additional potential in gas bearing reservoirs. The practice allows operators to re-enter existing vertical wells and to drill multilateral horizontal wellbores thus maximizing gas productivity in mature fields. Logging While Drilling (LWD) tools such as Nuclear Magnetic Resonance (NMR), acoustic, resistivity, pulsed neutron, etc. while used in conventional drilling to actively support geosteering operations, until now are un-available in the industry for UBCTD (hole diameter about 3 inches) applications. However direct characterization of cuttings could play, in this context, a pivotal role in support of geosteering in UBCTD operations. This work describes how Advanced Automated Cuttings Analysis (AACA) using a wellsite deployable SEM-EDS system was used to create a detailed lithotype scheme focusing on mineral texture and composition for a shallow carbonate interval that has a strong diagenetic over-print, which erased the pre-existing biostratigraphic drilling signature. Data generated by the technique could help with UBCTD geosteering decisions that could increase wellbore contact with the known sweetspot thus improving a well’s total gas productivity.