Published: 05/15/2018
Published: 05/15/2018
The primary oil reservoir of the Mumbai High field is fractured limestone that has been severely depleted since the field was discovered in 1974, making heavy-to-total fluid losses common in this area.
An operator needed to drill an 8 1/2-in HPHT exploratory well near this reservoir. Kicks and partial losses were observed within in the 4.6 ft [1.4 m] between 8,071.85- and 8,076.44-ft [2,460.3- and 2,461.7-m] MD. In the second run, the operator experienced total losses, with a final dynamic loss rate of 80 bbl/h [12.72 m3/h] at 322 galUS/ min [1.22 m3/min] and static losses at 0.5 bbl/h [0.08 m3/h]. The operator needed a way to prevent these losses before continuing.
After noting the success that the FORM-A-BLOK AS pill had when used previously in wells in the area, M-I SWACO, a Schlumberger company, proposed using the same pill to curb the losses. To make 100 bbl [15.89 m3] of 15.8-lbm/galUS [1,893.26-kg/m3] pill, 35 lbm/bbl [100 kg/m3] FORM-A-BLOK AS pill was added to drill water.
After pumping the FORM-A-BLOK AS pill, dynamic losses were eliminated at 250 galUS/min [0.95 m3/min], and the pill was accepted by the operator as a successful solution.
Challenge: Mitigate total losses in highly fractured, porous formation.
Solution: Use the FORM-A-BLOK AS acid-soluble lost circulation pill to mitigate losses.
Results: Completely stopped and prevented further losses at 250 galUS/min [0.95 m3/min] flow rate.
