Logging while drilling, Measurement while drilling and Geo-steering plays a vital role in ERD as these technologies together guide the well in the right direction and keeps the well in the play area for maximum length and hence reaching the target finally. This real-time information bought from the subsurface helps the driller to achieve the desired results.
Scenarios where Extended Reach Drilling is preferred
One of the main reasons of adopting ERD by operators is to avoid offshore drilling. Currently operators are employing land rig to reach the offshore target by reducing the cost of drilling. This helps operator to reduce environmental impact, well site infrastructure and operational footprints. At the same time it gets the maximum reservoir exposure to produce Oil & Gas from the zone of interest.
Secondly, environmentally sensitive and protected areas (which are previously inaccessible) can be approached to reach reservoirs in developed through ERD technology. Under this scenario Artic is a good example where ERD technology is very appropriate. Recently it has been observed that ERD is used to improve recovery in offshore fields. Use of ERD in offshore operations reduces the field development cost.
The main technological challenges faced in ERD include controlling torque and drag, fluid circulation, maintaining directional control, hole cleaning, managing the mechanical loads on the drill string, buckling, Limited WOB and downhole pressure etc.
Typically, the ERD operations are stopped when one or more of the following occurs:
Current trend and ERD recod
In order to access reserves and extend the life of mature fields, a strong demand for cost effective ERD has increased currently. As the ERD envelope has rapidly evolved during the l990s, many operators are now reassessing field opportunities previously considered uneconomic, when an onerous capital investment in new equipment was necessary. The industry is looking into the possibility of doing highly deviated extended reach wells in deep water environments. Before doing so different simulations are done to investigate which factors will limit the maximum well trajectory and to figure out of far it is theoretically possible to drill in horizontal and vertical direction.
As per recent industry news, Rosneft (Russian oil and gas operator) has completed drilling world’s longest ERD well in Russian Sakhlain island. As revealed by Rosneft in April 2015, well O-14 in Chayvo field has reached a record breaking measured depth of 13,500 m with length of horizontal section is 12,033 m.