Characterization of non-matrix type and flow potential using lost circulation information

Autor: James M. Degraff, Paul J. Moore, LaOde Ahdyar, Fermín Fernández-Ibáñez, Andrea Nolting
Rok vydání: 2019
Předmět:
Zdroj: Journal of Petroleum Science and Engineering. 180:89-95
ISSN: 0920-4105
DOI: 10.1016/j.petrol.2019.05.023
Popis: Lost circulation zones (LCZs) provide valuable information about the properties of non-matrix features – i.e., fractures and karst – intersected by wells during conventional drilling, including information about the type, size, connectivity and flow potential. The magnitude of the loss rate and lost volume should reflect the nature of the non-matrix feature responsible for losses. For example, the total volume lost in each of these zones provides a minimum volume of connected pore space, whereas the instantaneous rate of loss suggests whether the LCZ is due to drilling into a cave (high rate of loss) versus a fracture (low rate of loss). We define and quantify each LCZ from information recorded in the drilling reports including top and base of the LCZ, maximum loss rate, and cumulative volume lost to the zone. Once each LCZ has been identified from the drilling reports, we evaluate wellbore images and caliper logs across each anomalous zone to determine the cause of the loss event – e.g., caves or fractures. Results suggest that caves are typically characterized by high lost rates (>50 m3/h or 315 bbl/h), while fractures and touching vugs are characterized by lower rates (
Databáze: OpenAIRE
Externí odkaz: