Abstract
The benefits derived from the use of solids-free high density (HD) brine completion fluids have been extensively documented. The technology to produce and utilize these HD brines was known for many years before they could be made commercially viable. Their use only became economical in the 1970’s when the technology was developed to recondition and re-use these HD brines until fully consumed. Recently, increased competition and cost cutting pressures have resulted in a reduction in quality standards. As a consequence, some operators have begun specifying new brines only. If this trend continues, the actual cost of these valuable salts and the added cost of disposal would be applied to the suppliers price after a single usage. It is this very situation that prevented operators from utilizing HD brines in the 1950’s and 60s. It was not in their best economic interest then nor is it today.
The central problem seems to be the confusion surrounding minimum standards for reconditioned HD brines. Unfortunately, some service companies and operators alike have begun accepting the removal of suspended solids as the exclusive criteria for brine restoration. While the simple filtration of a completion fluid to some arbitrary level may appear cost effective, unseen inherent problems may compromise the functionality of the fluid, be damaging to the formation, complicate normal rig operations, and contribute to unexpected additional cost.
This paper provides guidelines for restoring used brines to new brine standards by addressing both physical and chemical contaminants. Laboratory procedures and operational guidelines are provided that establish methods for identifying problematic contaminants and simulate the brine specific reclamation techniques and field application requirements. Standards for restoring used brines to new/non-damaging compositions are also provided.
