Improved Method of Setting Successful Cement Plugs

Journal Article · Thu Nov 01 04:00:00 EST 1984 · J. Pet. Technol.; (United States)

DOI:https://doi.org/10.2118/11415-PA· OSTI ID:5941453

Smith, R C; Beirute, R M; Holman, G B

Setting openhole cement plugs has historically been a difficult task. Often, several attempts are required to set a cement plug before one is obtained that has sufficient strength for sidetrack and is at the intended depth. It is our opinion that unstable flow behavior, resulting from the heavy weight of an unset cement plug resting on top of a lightweight mud, is one of the main causes of plug failure. The common practice of using open-ended drillpipe or tubing to spot the plug is also a major contributor to unsuccessful plug setting. This paper presents a placement technique and materials design that have resulted in a successful plug on the first attempt in many field cases where previous plug setting was difficult. Several case histories are presented. To examine the instability problem associated with cement plugs, an experimental investigation was conducted. This investigation consisted of setting cement plugs of known densities and rheological properties on top of drilling muds having known properties. The experiments were conducted using lucite pipe to simulate hole or casing and using copper tubing as the drillpipe. In each test, the hole was initially filled with drilling mud. Then, cement was displaced through the simulated drillpipe to displace drilling mud up the annulus. The ability of the cement plug to remain where it was placed was observed visually and correlated with other experimental observations. This paper includes the results of the experimental investigation. The main conclusion of this investigation is that the stability and quality of a cement plug for sidetracking or any other purpose can be greatly improved through the use of our new placement technique.

• Research Organization: Amoco Production Co.
• OSTI ID: 5941453
• Journal Information: J. Pet. Technol.; (United States), Journal Name: J. Pet. Technol.; (United States) Vol. 36:12; ISSN JPTJA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
BUILDING MATERIALS
CEMENTING
CEMENTS
CLOSURES
DENSITY
DRILL PIPES
DRILLING EQUIPMENT
EQUIPMENT
FLUID MECHANICS
INSTABILITY
LABORATORY EQUIPMENT
MATERIALS
MECHANICS
OIL WELLS
PERFORMANCE TESTING
PHYSICAL PROPERTIES
PIPES
PLUGGING
RHEOLOGY
SIMULATION
STABILITY
TESTING
WELLS