A key element in the offshore drilling supply chain is the onshore supply base. The wastes most commonly associated with offshore E&P activities include: Drilling fluids, drill cuttings, produced water, treatment, workover, and completion fluids, deck drainage, produced sand, naturally occurring radioactive materials, and other assorted wastes.
What is a shorebase?
Law Insider (2018) defines an oil and gas shore base as “onshore support facilities that during drilling, development and production operations, provide services like receiving and acting as a transshipment point for supplies, materials and equipment; debarkation point for drilling and production personnel and services; communication, scheduling and dispatching center; and other associated functions.”
In essence, a shore base or supply base is the onshore logistics hub for any offshore E&P operation, be it seismic, drilling, pipeline, platform installation or production operations.
Generally speaking, a shore base will contain the following at a minimum:
- Quay of sufficient length and draft to accommodate the vessels being utilized.
- Marshalling yard space near to the quay for the mob/demob of goods coming on or off supply vessels.
- Laydown yard space for the temporary storage of containers, tubulars, and other oilfield equipment that moves on and off supply vessels.
- Warehousing (may be covered or uncovered, with or without shelving, climate controlled or not depending on requirements of the clients).
- Offices for shore base staff (may be fixed buildings or temporary mobile offices).
- Heavy lift equipment (forklifts, cranes, pipe handlers, etc).
- Labour (stevedores and other port labour as well as equipment operators).
- Roadways of sufficient quality to allow trailer trucks to move in and out of the facility unimpeded.
- Access to potable water, drill water, fuel (these may be via dedicated pipelines to the quayside or via trucks or barges).
- Access to electrical power of required voltage (connections directly to the quayside must exist).
- Sufficient security including fencing, guard booths, CCTV, etc.
- Sufficient parking for staff and visitors.
What items are transported to/from the shorebase?
All materials needed for drilling operation, including but not limited to:
- Drill Pipe
- Drill Collars
- Wireline tools
- BHA components
- Drilling fluid
- Chemical additives for drilling fluid and cement
- Well testing equipment
- Gravel Packing equipment
- Drill Water
- Potable Water
- Fishing Tools
- Miscellaneous items like IT equipment, spare parts, stationery, etc
For offshore operations, there are several specialized services which require 3rd party support. These are either contracted directly by the operator or via the logistics or shorebase supplier.
An offshore container is a “portable unit, specially designed for repeated use in the transport of goods or equipment to, from or between fixed and/or floating offshore installations and ships.”
Handling containers at sea means they have much greater demands place upon them, so they must be much tougher and more durable to withstand the harsh conditions of an offshore environment.
There are three categories of offshore containers:
- Offshore freight containers: Built for the transport of goods, which can include general cargo containers, cargo baskets, bulk containers, special containers, boxes and gas cylinder racks. These include containers for dangerous goods like explosives.
- Offshore service containers: Custom-built containers for a specific task that are generally temporary. These include labs, workshops and power plants.
- Offshore waste skip: A container that holds waste that can be open or closed.
Offshore containers are also known as “skids”, as they are often used to transport large components to drilling and production rigs. These may just be simple as frames that hold the contents.
Waste Management of offshore drilling
Nonhazardous waste generated offshore also includes garbage (food waste, bottles, bags, etc) and Waste generated at the rig is brought back to the shorebase in waste skips for disposal.
Note that waste disposal is one of the trickiest elements of a drilling operation. The Basel Convention dictates that hazardous waste must not be moved from one country to a next. This means that hazardous waste generated in offshore drilling almost certainly has to be disposed of in-country. Therefore, waste typically goes to the secondary shorebase to be stored until proper disposal can be carried out.