We are planning to drill adjacent wells within the same conductor pipe with splitter wellhead (2x wells in One CP). The conductor pipe might be angled (with a small angle under 10°).
As per vendor procedure, before drilling the first well (16in) a downhole guide is lowered in the second slot (of the same CP) to reserve the space for the next wells. Those DH guide are similar to big stabilizers with 15.67in OD.
Having the CP inclined imply that the relative position of the DH guide string and the 16in BHA at surface won't probably be the same downhole. The DH guide might lay on the low side or maybe not. This is exactly the uncertainty that increase the risk of collision when drilling the second well.
Do you have any idea of a process to determine with precision the position of the BHA and the downhole guide relative to each other at the CP shoe depth? pip tag marker in the DH guide string and Azimuthal GR on the Drilling BHA?
The solution is perhaps very different from our proposition. Do you have any other options to solve our question?
Thank you in advance,
Mike Tony CHEMBOU
Note that I don’t have much experience with splitter WH, but I would suggest what follows, based on experience in some well intercept and re-entries operations.
Your CP being set with 5-8° inclination helps defining relative position of slots in slots with the use of an e-line oriented Camera. Obviously it requires to have your CP full of clear water.
With your DH Guide in place in one slot, RIH an open-ended string with a couple of centralizers down the 2nd slot CP, circulate clear water, then run your e-Camera down the open-ended string. Do not run the e-Camera past the open-ended string, but camera optical nose just out of the re-entry guide. Observe where your open-ended string lies relative to your DH guide.
Your e-Camera optical may be self-orienting to gravity, if not a gravity measuring tool can be coupled to your e-Camera and survey tool Tool Face scribed with a marker on the e-Camera optical.
Based on the relative position observed between your DH guide and Open-Ended String, you will know which direction to high side to nudge your first well not hindering exit of your 2nd well, mitigating your collision risks.
Hope this helps