Abstract

Waste management will play an important role in delivering an environmentally sound well. If, however, a project requires the operator to drill hundreds of deep development wells and in close vicinity of communities, waste management even becomes a critical success factor. There is simply no room for error. The drilling and stimulation of these large number of wells will generate large volumes of solids and fluid waste, which must be managed efficiently, strictly controlled and comply with the requirements of local regulators.

Waste generated during the drilling phase constitutes of Water Based Mud [WBM] cuttings, Synthetic Based Mud [SBM] cuttings and WBM fluids, whereas frac flow back water will be the constituent following frac stimulation. To encompass all of these waste streams in an integrated waste management system, the project team of Fushun and Jinqiu [Sichuan, China] initiated a plan to cover waste generation, waste transportation, final disposal process and a waste tracking system as per ISO guidelines and in agreement with the Company's global Health, Safety & Environment [HSE] policy and procedures.

The waste management is divided in two phases. In Phase I the solution sought is to utilize a recycling method in the field to minimize the generated waste volumes. This comprises a disposal waste stream for each waste category. For WBM cuttings, solidification and burial in-situ would minimize the impact on drilling operations. For WBM waste fluid and frac flow back water, in-situ pre-treatment and then transporting these effluents to industrial waste plants has proven to be a workable and efficient solution. In contrast, OBM cuttings are treated as hazardous waste and are incinerated in a hazardous waste disposal plant.

There are a number of challenges to face, such as heavy land transportation, resistance from local farmers in a populated area, meeting the strict and the mandatory requirement from the Environmental Protection Bureau [EPB], whilst at the same time aiming for overall well cost reduction and project delivery. Another limiting factor is the number of qualified local waste disposal vendors in the Sichuan area.

But when there are challenges, there will also be opportunities. This paper aims to focus on these opportunities and will thus home-in on Phase II, currently under development, which comprises a pit-less drilling and stimulation approach, with all waste transported to a dedicated waste plant and waste disposal location.

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