A series of multilateral well segments that trunk off a main horizontal well. The appearance closely resembles the ribs of a fish skeleton trunking off the main backbone.
Fishbone Wells are series of multilateral segments that fall into a horizontal well. They are called so because they look like the ribs of the skeleton a fish. A Fishbone stimulation system is ideally used in onshore low permeability tight gas reservoirs.
The vertical branches make vertical flow path which is similar to hydraulic fracturing
. They are open hole liners that link the well with the reservoir and perform all fishbone operations. For instance, circulating the fluids with the rig pumps and setting the liner hanger slips become easy with the help of a fishbone stimulation system.
Fishbone wells are one of the most effective ways used to improve the production rate of wells. The design of the wells is a complex process as it focuses on the optimization of branch length, branch number, and branch angle.
The process is an effective method for economic development at low permeability, low yielding oil reservoirs, and low abundance. Some advantages of the wells include:
- They provide high well production rate.
The engineering costs can be reduced.
They reduce the economic risks in heterogeneity stratum.
Moreover, Fishbone wells can generate a net present value similar to fractured wells and their productivity does not decline over time.