Properly designed underbalanced drilling fluids can limit formation damage

Journal Article · Mon Apr 29 04:00:00 EDT 1996 · Oil and Gas Journal

OSTI ID:220628

Churcher, P L; Yurkiw, F J ^[1]; Bietz, R F; Bennion, D B ^[2]

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1. PanCanadian Petroleum Ltd., Calgary, Alberta (Canada)
2. Hycal Energy Research Ltd., Calgary, Alberta (Canada)

Drilling fluids for underbalanced operations require careful design and testing to ensure they do not damage sensitive formations. In addition to hole cleaning and lubrication functions, these fluids may be needed as kill fluids during emergencies. PanCanadian Petroleum Ltd. used a systematic approach in developing and field testing a nondamaging drilling fluid. It was for use in underbalanced operations in the Glauconitic sandstone in the Westerose gas field in Alberta. A lab study was initiated to develop and test a non-damaging water-based drilling fluid for the horizontal well pilot project. The need to develop an inexpensive, nondamaging drilling fluid was previously identified during underbalanced drilling operations in the Weyburn field in southeastern Saskatchewan. A non-damaging fluid is required for hole cleaning, for lubrication of the mud motor, and for use as a kill fluid during emergencies. In addition, a nondamaging fluid is required when drilling with a conventional rig because pressure surges during connections and trips may result in the well being exposed to short periods of near balanced or overbalanced conditions. Without the protection of a filter cake, the drilling fluid will leak off into the formation, causing damage. The amount of damage is related to the rate of leak off and depth of invasion, which are directly proportional to the permeability to the fluid.

• OSTI ID: 220628
• Journal Information: Oil and Gas Journal, Journal Name: Oil and Gas Journal Journal Issue: 18 Vol. 94; ISSN OIGJAV; ISSN 0030-1388
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
ALBERTA
DRILLING FLUIDS
FORMATION DAMAGE
MITIGATION
NATURAL GAS WELLS
PERFORMANCE TESTING
ROCK-FLUID INTERACTIONS
WELL DRILLING