Best Cementing Practices for curing losses in carbonate reservoir with big fracture opening / fault

Dear Forum Members,

Here in Marmara Sea, south of Istanbul, while drilling 8-½” hole section in the Gas Storage Reservoir field, we have encountered big fault or large fracture just right after we penetrated our carbonate reservoir section at 78o inclination.

After numerous attempts to cure losses with conventional LCM materials decision was made to pump G-class cement to plug off the thief zone. Distance from shoe to loss zone = 77m, to current TD = 88m. MW in hole weighted brine 10.8 ppg.

Static loss rate = 40-60 bph. Dynamic = 200 bph. Reservoir pressure – 2020 psi with top at 1172 mTVD or 10.1 ppg EMW.

We seek the best practices for pumping cement in similar conditions. Specific questions are: 

1. Squeeze or let the cement fall under gravity to the loss zone?
2. Slurry density
3. Pumping rates
4. Spacer fresh water?
5. Minimum volume to pumps
6. Rotate the string or not (5” Open Ended Pipe)? What rpm?
7. Reciprocate or not?
8. Any specifics for the recipe?

I appreciate your other advise or questions.

Best regards

Yagiz 

Drilling Engineer

27 Answer(s)

Support Spread

We need the support of our members to keep our forum online. If you find the information on spread useful please consider a donation

Donate