While the percentage of horizontal and deviated wells is increasing, so are other risks. The dreadful call comes in from your field consultant, "The Logging Field Supervisor just told me that the logging tools are possibly stuck in the hole," what is the plan of attack?
Here is a quick outline for what to do, and expect, during this possible multi-million-dollar hit to your company on rig time, logging tools costs and radioactive abandonment cost. Also, if you aren’t in this situation and just want to avoid the million-dollar consequence, there are other options to provide risk-free logging data.
4 Questions your Field Consultant should ask a logging supervisor:
To begin, you want to make sure you provide your consultant with every available option to get out of this possible well abandoning issue. After the field supervisor running the service makes his way over to the consultant’s shack, the main things you wants your consultant to find out from that supervisor are:
Where the logging tools are stuck?
or, Key Seated Wireline
Are the tool calipers closed to provide the least “drag” during pull attempts?
Have they called their superior to get an approval to do a max pull with the Wireline truck?
Has the most experienced “operator” on the winch attempted to manipulate the tools free?
So the logging tools are stuck. Now what?
If running Wireline and sources are in the hole, you can attempt to retrieve tools by using the following two methods:
Side Door Over Shot
Requires a custom side door tool that may not be readily available
Process cannot be used if Wireline is key seated
Cut and Thread (most common)
Very time consuming as Wireline must be “cut and thread” back for every drill pipe inserted
Tool connection is obviously lost due to Wireline cut
If tools aren’t retrieved the first time, the company is required to try multiple times, with different methods, until the regulatory agency decides that it is not feasible to continue fishing. Keep in mind that during the fishing procedures, the drilling mud must be continuously monitored to ensure the sealed source hasn’t ruptured. What this adds up to is your million dollar, non-producing well is now left standing.
Now with the logging tools and radioactive source expenses on the weight of your shoulders, you are still required, by law, to make sure:
Source must be immobilized and sealed in place with a cement plug
A plaque is then installed on the well head to identify the lost radioactive sources in the well and the entire operation must be abandoned
Yes open hole logs can be generated without any of the risks specified! The risk grows exponentially as the number of wells that are deviated or horizontal increase substantially, but there are other methods out to guarantee the safety of your well.