BORECLEAN®

Clay removal additive for filter cakes in open-hole/screen completions

DESCRIPTION

Boreclean is an acidified polyethylene glycol mixed in brine. Exposure of deposited clay drill solids to this solution during the completion phase after the polymer fraction of the filter cake has been chemically degraded improves overall filter cake removal. Preferential adsorption of the polyglycol and displacement of water from the clay surfaces lessens stickiness, surface adherence, and subsequently aids in circulation of these particles from the borehole, prior to producing the well. This reduces the potential for filter cake insolubles to become entrained in a sand exclusion assembly and limit reservoir production.  Boreclean is packaged in 50 lb or 25 kg sacks. 

APPLICATIONS
Boreclean may be utilized as part of a completion sequence utilized to break filter cake polymers, attack clay solids, and dissolve primary bridging solids. A typical procedure includes:
  1. Polymer breaker solution
  2. Brine spacer
  3. Acidic/polyglycol soak solution
  4. Circulating brine wash

MIXING INSTRUCTIONS
Normal treatment is 100 lb/bbl Boreclean mixed into a HCl/brine solution.

FLUID COMPOSITIONS, FILTER CAKE REMOVAL TREATMENTS,AND RETURN PERMEABILITIES FOR NaCl AND CaCO3 SYSTEMS
Sample A B
Brine, bbl 0.96 0.95
Brine type 10.0 ppg NaCl 3% KCl saturated with NaCl
Xanthan gum biopolymer, lb/bbl 1.25 1.2
Derivatized starch, lb/bbl 3.75 3.8
Sodium thiosulfate, lb/bbl -- 0.25
Magnesium peroxide, lb/bbl -- 0.5
Calcium carbonate, lb/bbl 38 --
Sodium chloride, lb/bbl -- 15
Rev dust, lb/bbl 30 30
Pierre shale, lb/bbl 5 5
SYSTEM TEMPERATURE(°F) SOAK TIME (hrs) TREATMENT RETURN FLOW(%)
1 2 1 2
A 175 2.5 5 10% HCl 5% HCl 40
175 2.5 5 10% HCl 5% HCl/100 lb/bbl Boreclean 85
B 100 8 -- 10% HCl -- 45
100 4 4 10% HCl 5% HCl/100 lb/bbl Boreclean 80
A - CaCO3 System B - NaCl System 1 - Polymer Breaker: saturated with respect to NaCl 2 - Clay Removal: saturated with respect to NaCl

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