Traditionally, deviated and horizontal wells have been challenging to service in a cost and time-efficient manner. Conventional technology requires large equipment to be mobilized and many heavy lifts in the offshore environment, sometimes with negative HSE consequences.
New technology on electric wireline has made it possible to access the entire well regardless of deviation and lateral reach. Wireline tractors and new mechanical services can be mobilized in a matter of hours and only require a crew of two people for many applications. Transportation can be done by helicopter to avoid the cost and time of mobilizing a full coiled tubing (CT) spread with bottom hole assembly. Additionally, fuel consumption, emissions and fluid discharges are reduced and heavy lifts are eliminated for the offshore environment.
Mechanical down hole wireline tools have also been developed to manage produced water. When wells produce up to 100% of water, mechanical tools can isolate the water to increase oil recovery. By reducing water entry at the source, the subsequent efforts and costs to address it are reduced along with the environmental risks.
This paper will illustrate how HSE benefits can be achieved through several case histories. One case history will show how time and crew requirements can be reduced when a wireline tractor and milling system were deployed to remove 42 ft of barium sulfate inside two wellbores. The scale was removed from both wells in 12 days – the same time it would have taken a CT unit to mobilize and demobilize offshore. Costs were reduced by 60% and crew requirements were reduced from 23 to 12 people compared which reduced human exposure to risks offshore.
Another case history will illustrate how produced water can be effectively reduced through e-line mechanical services. In an offshore well in Norway, a leak was detected in the tubing, which resulted in 85% water cut. A wireline tractor and stroker were applied to install two straddle packers in order to isolate the water-producing area. Water cut was reduced to 5% and oil production increased 800%.