Jb. Hall et Bm. Wijngaards, Slickline power unit on coiled tubing provides innovative solution for setting a nippleless lock in a multilateral completion, SPE DRILL C, 15(2), 2000, pp. 84-91
In the procedure most often used for drilling laterals from horizontal comp
letions, a retrievable bridge plug is set in the casing. The bridge plug se
rves as the base for orienting and setting the whipstock used to drill the
window in the casing so that the drilling of the lateral section can be ini
tiated.
In monobore completions, operators can drill lateral sections through the t
ubing, and if coiled tubing drilling technology is used, this procedure can
often be performed without killing the well and pulling the in-place compl
etion. Drilling the horizontal lateral with the well flowing offers the adv
antages of efficient removal of the cuttings and reduced formation permeabi
lity impairment.
The retrievable bridge plug commonly used when being set with coiled tubing
is the inflatable bridge plug. This plug con be run through most tubing re
strictions and the element inflated to create the seal against the casing w
all. If, however, casing damage or other well conditions prevent the inflat
able bridge plug from being set, the operator may be left with few viable o
ptions for completing the drilling program.
This article will discuss such a case. In this scenario, repeated attempts
to set an inflatable bridge plug failed during the operator's drilling prog
ram. To provide a solution, a slickline running tool and nippleless lock ma
ndrel were adapted for use with coiled tubing. Combining the slickline runn
ing tool and lock mandrel with coiled tubing had never before been attempte
d. In addition to providing a cost-efficient, innovative solution for a dif
ficult service problem, the capabilities gained by combining these technolo
gies shaw promise of enlarging the scope of viable alternatives for other s
ervice needs.