A Step towards to Minimize Environmental Footprint: An Innovative System to Dispose Generated Cement Waste on a Zero Discharge Artificial Island

Abstract

Because environmental regulations are rapidly evolving towards stringent requirements, oil and gasoperators are confronted with a great challenge of disposing drilling waste, especially when operating on an artificial island located 120-km offshore and under a Zero Discharge Policy. The paper describes an innovative engineering solution that significantly reduces the time, cost and the associated safety hazards with disposing of the cement waste generated from primary cementing operations and drilled cement cuttings. The earlier disposal process implemented on the island included collecting, storing, and shipping the cement waste to an onshore treatment facility. This process was proven to be cumbersome, time-consuming and extremely expensive. Additionally, external factors such as logistics constraints, weatherconditions, and storage skips availability had a direct negative impact on the process, resulting in a massive accumulation of waste on the island. On the other hand, the newly developed disposal process utilizes existing resources, with minor modification, within the artificial island. A step-by-step procedure was developed to dispose all excess cement and drilled cement cuttings generated without any negative HSE impact. A pilot trial was performed successfully by injecting the cement waste into the shallow loss zone through the annulus, and therefore, the process was generalized to both island and found to be safe and efficient operationally and economically. The new innovative method simplifies the disposal process to a one-stage operation that is performed along with the primary cementing operation. By implementing the process, no cement handling on surface is needed, resulting in a 90-percent drop in the cost.. The number of people involved is reduced as well. Consequently, a reduction in the hazard exposure and the potential lost time incident (LTI) is achieved.