Extended Reach Drilling
Extended Reach Drilling (ERD) techniques are increasingly being used to target hydrocarbons far from the surface or otherwise difficult to access areas of oil and gas reservoirs. In addition to achieving enhanced field recovery, ERD can facilitate drilling around environmentally sensitive areas which have environmental and regulatory restrictions.
This is a diagram of an ERD well in the environmentally sensitive Santa Barbara Channel offshore California. In 2005, Baker Hughes provided technology and services to drill to new hydrocarbon targets, sidetracking off the original 2-D ERD well above (shown in blue). Baker Hughes drilled a complex 3-D ERD well with two targets (shown in red), thus enabling the operators to access untapped areas of the reservoir without the need for new platforms or other environmental disturbance.
Using Baker Hughes' directional drilling products, a wellbore can be drilled as far as seven to eight miles away to reach hydrocarbons that may lie under sensitive onshore or offshore areas.
ERD is used within the industry to allow offshore operators to drill, complete and produce offshore fields from a smaller number (even one or two) offshore platforms. This reduces the number of drilling and production locations and therefore the capital and operational expenses as well as reducing the risk of obstructions to shipping and other sea traffic.
The AutoTrak Rotary Steerable drilling system allows complex 3D well paths to be drilled in an efficient manner while allowing real-time formation logging and geo-steering. Improved placement of the well enhances the volume of recovery of hydrocarbons, reduces the production of unwanted water and allows economic completion and production of small reservoirs and thin bed zones that just a few years ago were considered stranded reserves.
In addition to minimizing disruption to habitats, environmental benefits include a reduction in the amount of drilling fluid used, as mud losses are minimized. This leads to reduced oil-on-cuttings which requires less processing energy and infrastructure. The need for fewer trips and fewer bottom hole assembly connections also enhances employee safety.
Multilateral drilling, a form of ERD, represents some of the oil and gas industry's most impressive engineering feats in terms of wellbore construction. As global hydrocarbon demands increase, these wells are the ones pushing the drilling engineering envelope in order to meet the world's demands in the safest, most environmentally conscious and cost-effective manner.
Several environmental benefits include:
- Smaller footprint
- significantly more reservoir exposure from a single wellhead
- much less drilling waste
- much less resources in the form of casing and consumables
- Longer productive life of the well due to lower drawdown pressure on the well
- Better recovery from fewer wells
- Ability to position this smaller surface footprint location in the most suitable place
Baker Hughes has provided multilateral drilling and completion technologies to the world's most complex and extensive multilateral field development—the StatoilHydro Troll field offshore Norway. At the time of discovery, Troll was known as a gas field which contained a considerable amount of oil. However, due to accessibility challenges in the reservoir's thin oil column, oil production from Troll was considered technically unfeasible. Working closely with StatoilHydro, Baker Hughes developed specific technologies and operational procedures to drill and recover the oil from the Troll field. Today, through the extensive use of precisely positioned multilateral wells, Troll has become Norway's largest oilfield and has delivered in excess of one billion barrels of oil.
The Troll field is Norway's largest oilfield. It is developed using the world's most complex multilateral wells to maximize production and recovery from the thin reservoir.