With the passing of "easy oil," the need for high-pressure, high-temperature (HP/HT) drilling and completion fluids has increased. This has, in turn, increased the need for sufficiently robust cleanup methodology. This requirement for high density, solids free cleanup fluids drove the investigation into the use of cesium formate as the base brine. The use of cesium formate brings unique challenges to the cleanup, most notably, the cost implications. The high price of cesium formate brine means that any losses could severely impact upon the cost of the cleanup operation. Furthermore, any brine used in cleanup pills that could not be recovered for re-use would have to be considered as lost. It was, therefore, imperative to return the brine to its original condition, thereby avoiding the need to dispose of a very expensive commodity. This paper will look at the laboratory testing surrounding the development of a high density cleanup fluid (HDCUF) and the ability to remove the contamination from the brine to bring it back to an acceptable condition. The cleanup spacers were made up with cesium formate brine and several approaches to remove the contamination were investigated. Contamination was from both the chemicals used to formulate the cleanup spacer and from the oil based drilling fluid that would be used to drill the wells. Nuclear Magnetic Resonance (NMR) Spectroscopy was used to measure the level of contamination in the brine. The results of the study showed that, using the method selected, it was possible to remove the cleanup chemicals to an acceptable level where the cesium formate brine was able to be re-used. This would enable the operator to recover the brine and avoid the significant costs from losing the volume and disposing of the waste.
|Title of host publication||Society of Petroleum Engineers - SPE/IADC Drilling Conference and Exhibition 2011|
|Number of pages||6|
|Publication status||Published - 13 Jun 2011|
|Event||SPE/IADC Drilling Conference and Exhibition 2011 - Amsterdam, Netherlands|
Duration: 1 Mar 2011 → 3 Mar 2011
|Conference||SPE/IADC Drilling Conference and Exhibition 2011|
|Period||1/03/11 → 3/03/11|