蘑菇传媒

Challenge: Partial lost circulation at a rate of 11 m3/hr (69.2 bbl/hr) was observed.

Solution: Use of a FORM-A-SQUEEZE pill to seal the zone where the partial lost circulation occurred.

Results: Waiting times were eliminated and operations costs were reduced.

The Situation

Drilling was being performed with a 12¼-in bit at 5853 ft (1784 m) with 1.30 SG (10.8 lb/gal) VERSADRIL invert-emulsion fluid and partial lost circulation at a rate of 11 m3/hr (69.2 bbl/hr) was observed. Pills containing 100 kg/m3 (35 lb/bbl) of lost circulation materials (LCM), M-I-X II Medium and CaCO3 M-70 and M-200 were pumped.

Drilling was continued with a partial loss of 5 to 11 m3/hr (31.4-69.2 bbl/hr) to a depth of 5,938 ft (1810 m) while pumping LCM pills, accumulating 110 m3 (692 bbl) of lost mud, resulting in suspension of the operation.

Client operating personnel met with 蘑菇传媒 engineers in search of a technical alternative to properly seal the loss zone and to continue with normal operations.

The Solution

蘑菇传媒 recommended the use of a FORM-A-SQUEEZE pill to seal the zone where the partial lost circulation occurred. A 50-bbl, 1.31 SG (10.9 lb/gal) FORM-A-SQUEEZE pill consisting of diesel, FORM-A-SQUEEZE additive, and calcium carbonate was prepared and blended.

• Having the bit at 5905 ft (1800 m), 40 bbl of FORM-A-SQUEEZE pill was pumped. Pressure: 600 psi, displaced at 800 strokes per min
• Lifted bit to 5459 ft (1664 m), circulated at a low flow rate of 10 strokes for 5 min; then pumping was suspended, annular preventor was closed, satisfactorily repressurizing with 200 psi for 10 min
• Pressure was discharged to zero; annular preventor was opened and initially circulated at a low flow rate. The flow rate was gradually increased until initial drilling conditions were attained: 120 strokes, 540 gal/min, 2200 psi. No mud losses to the formation were observed
• The 12¼-in section was taken to bottom, circulated at a low flow rate, increasing little by little until reaching and maintaining 540 gal/min, and continued drilling with normal circulation

The Results

After pumping the FORM-A-SQUEEZE pill:

• A complete cycle was circulated at 540 gal/min, keeping normal levels
• Drilled to bottom without experiencing lost circulation, keeping normal levels at surface
• No waiting-on-cement times were required
• Continued drilling at the scheduled depth with normal circulation
• Waiting times were eliminated
• Operational costs were reduced
• Continued drilling the stage below scheduled times