Vol. 226 No. 12

Rig Floor Equipment

ATC cleans mud tanks, lowers costs

M-I Swaco has introduced its new proprietary Automatic Tank Cleaning (ATC) system for mud tanks onboard mobile drilling rigs, platforms, and supply vessels to the Gulf of Mexico. The system is designed to reduce cleaning time and manpower, while minimizing and perhaps eliminating confined space entry. The company says that the ATC system improves safety, reduces risk, reduces waste, and minimizes downtime during the cleaning operation.

Based on the tank configuration, Tank Cleaning Machines (TCM) are positioned within the tank to optimize the cleaning pattern. They are then connected to a portable skid containing the feed pumps. A powerful waterjet cleans every surface inside the tank using a mixture of surfactant and water.

Rig tank pumps or a portable slop pump removes the washwater and tank residuals to a wash Water Recycling Unit (WRU), where the solid and liquid phases are separated. The liquid phase is sent back to the TCM for reuse until it is highly contaminated by fines. At the end of the operation, the solid waste is safely removed from the installation in containers or reused to build new mud volume, since it is predominantly barite. In cases where the operator has an overboard permit, the process is simplified, and the slop will be disposed of properly.

The system has been used successfully on a number of high-profile platforms and rigs in the Gulf of Mexico. On one mobile offshore drilling unit, engineers calculated that the system reduced tank cleaning personnel by 40%, reduced cleaning time by 50%, and reduced confined space entry by 90%.