I have a client I am working with which is currently unable to gain approval from the local ministry for a hydraulic frac because of API HF1.
The client cemented the final casing, a 7â…" x 4"" liner in place with a flexible cement (with latex) but encountered losses while cementing. The CBL shows an ok bond 80 m from TD (4720m), there are strings another 600 m up but lots of free pipe. 7" liner set at 3938m, good cement job, and other casings have good cement also.
To make this well viable, a frac is required (in fact 4 fracs were originally planned) in the cemented zone, but the perforations possibly could only be 40 m below the TOC. This is a vertical well, and the liner top packer is also in place and tested.
The next step is to try and convince the ministry that what we are doing is safe and controlled.
- I have seen problems before logging these flexible cements to the extent that the client changed logging company to see good results, has anyone else experienced this?
- As the API HF1 is a guideline, (cement isolation of 500 ft above producing zone) is it something that has to be followed, abides by? What about open hole completions with no cement, only packers?
- We have reduced the maximum pressure to 10,000 psi (completion and tree rated for 15,000 psi) and have all the regular safety items in place. Any other suggestions on how to convince the ministry?