THE WELL MILLER® RCB QUICKLY IDENTIFIES DOWNHOLE OBSTRUCTION IN COLOMBIA

Background

In early 2018, a client in Colombia discovered a drill pipe restriction at 4,570 ft while attempting to perform a free point log to release a stuck 5” heavy-weight drill pipe. The client needed to quickly identify the nature of the obstruction material and its root cause in order to continue the operation to free the stuck pipe. The client called Welltec® for a ready-on-arrival (ROA) operation with the Well Miller®218 Reverse Circulating Bit (RCB) to perform a clean-out through the 5” heavy-weight drill pipe to regain access down to the bottom-hole assembly and help determine the source of the obstruction.

OPERATION

Welltec® mobilized to the job site with the Well Tractor® and Well Miller® RCB. According to pre-job simulations, the inclination of the well was not significant enough to require the Well Tractor® for conveyance. However, the Well Tractor® was included to provide weight-on-bit and to counter reactive torque on the cable while milling.

After several approaches to the obstruction depth during an approximately one-hour run, the field engineer noticed the tool power flattening, indicating the Well Miller® RCB was no longer milling or making progress. The tool string was pulled back, and the cable tension jumped to 3,000 lbs indicating that the tool string was now stuck. The winchman worked for 20 minutes before finally freeing the toolstring. The client decided to pull out of hole to evaluate the recovered debris.

On the surface, an evaluation of the bailer contents showed that the Well Miller® RCB recovered a thick, fiber-clay, mixed debris. The obstruction was an undesirable consequence of chemical products injected into the well to release the pipe stuck downhole. The client then met with Welltec® and the drilling fluid team. The consensus was that the material likely went all the way to the bottom of the drill pipe.

ACHIEVEMENTS

Welltec® responded quickly to this last minute request. The client was very pleased by the response and Welltec’s ability to adapt its tools and personnel to deliver excellent service in a ROA mode of operation.

This was the first time the Well Miller® RCB had encountered this kind of thick, fiber-clay, mixed debris, yet was still able to circulate it into the bailers. The tool proved to be a slim, robust solution for quickly identifying the nature of the obstruction material, whether drill cuttings, drilling fluid related or mechanical failure of the pipe, thus providing the client with the information needed to decide on the next operation to be deployed.

Welltec’s personnel and tools achieved the client’s objectives, and the operation was completed flawlessly, safely and with zero non-productive time.

WELL TYPE: ON-GOING DRILLING
WELL FLUID: DRILLING MUD
BOTTOM-HOLE TEMPERATURE: 186°F AT 4010 FT
BOTTOM-HOLE PRESSURE: 1920 PSI AT 4010 FT
INCLINATION: 69° AT 5175 FT

 

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