DEVELOPMENT AND FIELD TRIAL OF 2 ENVIRONMENTALLY SAFE WATER-BASED FLUIDS USED SEQUENTIALLY TO FREE STUCK PIPE

Diesel-based spotting fluids have historically been used to free diffe rentially stuck pipe. Increasing environmental regulatory pressures ha ve prompted the development of environmentally acceptable water-based spotting fluids. In spite of their widespread application, these new f luids have had only sporadic success in freeing differentially stuck p ipe in the field. An extensive laboratory research project was initiat ed to identify potential chemistries that could offer increased perfor mance and maintain environmental acceptability. Literature reviews rev ealed that previous spotting-fluid research had focused mainly on the spotting fluid providing lubrication between the drillpipe and mud fil ter cakes. Laboratory data also revealed that the best preforming conv entional spotting fluids were highly toxic to mysid shrimp. In accorda nce with the new findings, a two-phase spot was developed. This paper details a field application that validated the concept of the two-phas e spot, and discusses its method of application.