Use of staged mill and mechanical whipstock saves sidetrack time and cost by up to 50%

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:372379

Kirkwood, Y S; Pritchard, M D

Due to the current marginal economic status of the petroleum industry, drilling a new well is more difficult to justify than ever before. Many operators have adjusted by recompleting old wells whenever possible. While the use of old wells reduces up front capital investment and alleviates some environmental concerns, the risk of formation damage can be much higher than drilling a new well. Although there are many methods of recompleting old wells, the experience at Mt. Poso indicates that none can provide a cleaner wellbore than a sidetrack completion. This paper discusses sidetrack operations using redesigned staged mill and mechanical whipstock. These sidetracks were performed in 1,800 ft. wells located at the Mt. Poso field, CA. The staged mill and mechanical whipstock system, called the Sidewinder, and is jointly invented by B and G Machine and Welding shop and Shell Western E and P Inc. The sidewinder is an enhanced version of the existing whipstock and staged mill technology that is currently overshadowed by the casing section mill. The initial result indicates the new method can reduce both time and cost by as much as 50% over the conventional casing section mill method. The margin of savings is even greater in wells with multiple casing strings.

• OSTI ID: 372379
• Report Number(s): CONF-950433--
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
CALIFORNIA
COST BENEFIT ANALYSIS
DESIGN
NATURAL GAS WELLS
OIL WELLS
OPERATING COST
OPERATION
RESOURCE DEPLETION
TOOLS
WELL SERVICING