Invert emulsion fluid helps operator save time and money while drilling on an HP/HT field
Previous publication SPE-174176-MS discussed the development of a novel high-pressure/high-temperature (HP/HT) organophilic clay-free (OCF) invert emulsion fluid (IEF) for first use as a combined reservoir drilling fluid (RDF) and screen running fluid (SRF) for stand-alone screen (SAS) completions. The current paper details the continued application of this innovative fluid in a total of five wells (four SAS, and one cased and perforated), and expands on the knowledge of fluid performance in the field.
Drilling performance, screen running performance, and productivity outcome were compared as previously determined on the first well. Additional finger printing was carried out to further understand the behavior of the 1.96-specific gravity (sg) OCF IEF: Downhole pressure measurements were compared to real-time hydraulic simulations, and were used to determine the actual pressure to break gels.
When drilling, all of the wells’ reservoir sections reached total depth (TD) without issue and with improved drilling performance. Rheology profiles were low throughout, delivering low equivalent circulating density (ECD) values. There were no incidents of barite sag during trips, and there was good gel development when static with gel strengths in excess of 15 pounds per hundred foot squared (lb/100 ft2, 10 min). Despite this, low flow rate testing (60 L/min) demonstrated very low downhole pressure to break gels (5 bar / 72 psi). At TD, fluid conditioning for screen running was achieved quickly (<12 hours). The 610 micron (µm) SAS were run to TD without issue. Since put on production, all the SAS wells completed with OCF IEF are producing with no apparent negative impact of the OCF IEF.
The OCF IEF has now been used successfully to drill five reservoir sections on an HP/HT field, delivering a low ECD performance without barite sag. The SAS completion wells were drilled and completed in the same fluid with an enhanced drilling performance and acceptable productivity outcome. The continued use of this single combination fluid has removed the need for a fluid displacement to a costly dedicated heavy brine SRF, resulting in substantial time and cost savings to the operation.
Click below to view further details and download the technical paper (PDF).
Source: Unconventional Resources Technology Conference, 1-3 August, San Antonio, Texas, USA
Authors: Morten Holger Strand (Halliburton) | Odd Halvard Lunde (Halliburton) | D. Nelson McMillan (Halliburton) | Duncan Clinch (Halliburton) | Tomasz Wroblewski (Statoil) | Niall Fleming (Statoil) | Sammy Hireche (Statoil) | Åsgeir Vatne (Statoil) | Mary Karunakaran (Statoil) | Zalpato Ibragimova (Statoil)