Abstract
At present, about half of Hassi Messaoud field output is being produced from hundreds of non-conventional wells. Two horizontal well (HW) applications are being used; new infill medium-radius horizontal wells in between productive zones and re-entry of dry-to-poor vertical producers all over the field using short-radius equipment.
The purpose of both projects is to recover incremental oil from poor-quality reservoir parts in order to boost overall production and improve oil recovery. Horizontal well technology has proven to be a good alternative to overcome reservoir areal heterogeneity and intercept natural fractures when present in the reservoir.
Although the two techniques have significantly improved production from marginal areas, several limitations and problems still have to be addressed. Challenges include weaker-than-expected productivities, rapid production decline rates in most wells, difficulties in data acquisition and inadequate completions for both remedial stimulation and zonal isolation. This study attempts to bridge production profiles with well and reservoir parameters such as; well length, permeability, vertical communication, lateral heterogeneity and anisotropy, near wellbore damage, pressure support, …etc.
The article presents a comprehensive analysis of horizontal wells in the field and investigates many aspects of the observed success and failure cases. It also discusses the benefits of underbalanced drilling and pre-perforated liner completions. By benchmarking current well performances, the paper draws some suggestions for well design and completion strategies for prospective wells.
