Mud to cement technology proven in offshore drilling project

Journal Article · Mon Feb 15 00:00:00 EST 1993 · Oil and Gas Journal; (United States)

OSTI ID:5938546

Javanmardi, K; Flodberg, K D ^[1]; Nahm, J J ^[2]

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1. Shell Offshore Inc., New Orleans, LA (United States)
2. Shell Development Co., Houston, TX (United States)

One problem with conventional cements is the incompatibility of Portland cement and the drilling mud. Expensive preflushes and spacer fluids have been used, often with limited success, to attempt to separate mud and Portland cement effectively. Under downhole conditions, most spacers are ineffective in preventing high viscosities and cement contamination problems which lead to poor primary cement jobs. One solution to this problem is to convert the drilling mud into a cementitious slurry, thereby eliminating the mud/Portland cement incompatibility. The existing mud solidification technologies have received limited acceptance because of high costs, complex design, and difficult field use. Shell Development Co.'s mud solidification technology (Slag-Mix) uses finely ground, granulated blast furnace slag as the cementitious agent. The slurry is activated with predetermined amounts of common alkaline chemicals (caustic or soda ash) and a thinner/retarder, such as lignosulfonate. Slag is only slightly reactive with water. Thus, the slag can be mixed in the mud through the mud hopper. At Auger, the slag was mixed and pumped with a conventional cementing unit. On two other operations (South Timbalier Blocks 295 and 300), the slurry was mixed in the mud pits and pumped down the well with the rig pump, thus eliminating the costs associated with conventional cementing units and services.

• OSTI ID: 5938546
• Journal Information: Oil and Gas Journal; (United States), Vol. 91:7; ISSN 0030-1388
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
DRILLING FLUIDS
SOLIDIFICATION
OIL WELLS
CEMENTING
SLAGS
WASTE PRODUCT UTILIZATION
BLAST FURNACES
CHEMICAL ACTIVATION
COMPATIBILITY
PORTLAND CEMENT
PUMPING
SLURRIES
BUILDING MATERIALS
CEMENTS
DISPERSIONS
FLUIDS
FURNACES
MATERIALS
MIXTURES
PHASE TRANSFORMATIONS
SUSPENSIONS
WELLS
020300* - Petroleum- Drilling & Production