Horizontal gravel packing technique for slim, cased holes in highly permeable zones: a single well case history

摘要

Gravel packing is becoming a common practice for controlling unconsolidated sands inhorizontal wellbores. So far. hori/ontal gravel packing has been applied almost exclusively to open holes with screeens in them. If a formation has a high permeability, and therefore a high fluid loss rate. placement of a gravel pack may be prevented by premature dehydration and bridging of the gravel pack sand in the wellbore/screen annulus. The usual method of preventing these high fluid losses and the resultant bridging is to damage the formation face prior to gravel packing. The damage mechanism is usually salt. calcium carbonate, or other particles that seal off the formation face. Once gravel packing is completed. the formation damage is (hopefully) remediated using acid or undersaturated brines to restore the comletion's productivity. Theere is, however, a risk that the damage cannot be successfully removed once it is gravel packed against the formation face. Acid diversion is also a problem when attempting to remediate damage in an open-hole gravel packed completion.