| Popis: |
Ilmenite (FeTiO3) was first introduced as a weight material in the North Sea area in the early 1980's. The quality of ilmenite suitable for drilling fluids was continuously improved to meet the drilling criteria. Ilmenite as a weight material offers many benefits over API barite such as high density (4.6SG), mineral hardness (6 Mohs), low heavy metals content, acid solubility and sustainability due to the large reserves.Currently there are certain drilling areas such as narrow pressure margin wells, HPHT wells, deep water, ERD, and slim hole, where API barite may not offer the required performance. For those wells a controlled rheology and minimal sag is the key to success and a specialty weight material can provide this. To fulfill such needs a micronized ilmenite grade (5μm) has been developed for use as a weight material for drilling fluids. The paper will show the testing of the new grade in both aqueous and non-aqueous drilling fluids. High temperature dynamic sag and filtration results will be presented. Acid solubility in hydrochloric acid will be highlighted. The new grade shows excellent dynamic sag, stable rheology and high acid solubility, which are very useful for many drilling operations particularly deep offshore drilling. On a top of the high performance this new advanced material is a cost-effective solution for some of the high costly drilling challenges. |
