A Decade of Experience—The Water-Based Thermal Insulating Packer Fluid

Abstract

The concept of 'flow assurance' has numerous connotations, especially when it comes to deepwater operations. Just a decade ago as deepwater came into vogue, flow assurance terminology would primarily refer to chemical injection technology. This quickly changed however, as demand for effective thermal insulation techniques to prevent annular pressure buildup, costly wax and asphaltene deposition, and gas hydrate formation escalated. Concurrently, effective water-based insulating fluids were introduced into the field, and were quickly accepted as a valuable method to retain heat in produced fluids and prevent heat loss to external annuli and surrounding environments. To date, over 70 installations of water-based insulating fluids have been completed, with applications ranging from controlling annular pressure buildup, to controlling heat loss in one or more riser annuli. This paper presents case histories from the originally designed insulation requirements in casing to control annular pressure buildup, to new evolutions applicable in modern risers. Operational details of installations completed, successful removal of the insulating fluid from wells, and successful re-use of the removed insulating fluids are presented. Results from an unexpected long-term shut-in, and field data connecting the effectiveness of water-based insulating fluids to model predictions are also presented.

Corrosion-resistant systems of formate packer fluid for G3/N80/TP110SS pipes at high temperature, high pressure and high H 2 S/CO 2 ratios

“…Its density falls within a wide adjustment range. The formate fluid does not generate sediment and has low formation damage [7][8][9][10]. The non-corrosive characteristics of formate itself further illustrate the degree of corrosion associated with formate packer fluid.…”