Albert, Larry (Allied-Horizontal Wireline Services) | Booher, Jason (Allied-Horizontal Wireline Services) | Wilson, Anthony (Allied-Horizontal Wireline Services) | Hamilton, Fraser (Impact Selector International) | Hradecky, Jason (Impact Selector International) | Dunning, Dustin (Wireco WorldGroup) | Pratosov, Vadim (Wireco WorldGroup)
An E&P operator was developing a reservoir and planned a horizontal well in an area where zones above the target cause drilling problems when trying to build angle and land the horizontal lateral. The operator suffered drilling difficulties on offset wells; therefore, it was decided to change the drilling plan for this prospect. The new plan required drilling through the target reservoir, into the formations below and then drill back up dip to the target. After reaching the base at a measured depth of 14,000 ft. the well plan required drilling up at maximum of 114° until reentering the target reservoir. Because of faulting in the area and required well direction, the target reservoir was dipping up at ∼10° laterally in the direction of the horizontal drilling target. To maintain position in the reservoir, the well had to drilled at ∼100° deviation to a measured depth of 21,100 ft.
This wellbore trajectory made normal wireline plug and perforating completion operations extremely difficult. The wellbore trajectory meant high frictions on the wireline when coming off bottom. Also, due to the toe-up trajectory there was risk the wireline tools would slide down the inclined casing during and after plug setting and perforating. If the tool position could not be maintained there was risk the wireline cable could be entangled and a stuck tool could result. If the tools overrun the wireline cable the result could be wireline cable next to the perforating guns when detonated and wireline cable severed. The E&P operator needed to know if this challenge could be met.
Alternatives to pump down plug and perforating could be very expensive (estimated $millions): Abandon acreage, Continue drilling attempts building angle above the target, Reposition surface location and drill down dip, Reduce angle and shorten lateral in target, or Coiled tubing conveyed plug and perforating completion.
Continue drilling attempts building angle above the target,
Reposition surface location and drill down dip,
Reduce angle and shorten lateral in target, or
Coiled tubing conveyed plug and perforating completion.
To meet the challenge several new methods and technologies developed for extended laterals were utilized. These products and methods included: advanced risk deployment modeling, jacketed wireline cable, addressable separation tool and downhole tension tool.
The winner of the 2016 SPE Drilling Systems Automation Technical Section (DSATS) Drillbotics competition, West Virgina University (WVU), will present its fully automated drilling rig at the DSATS Symposium at ATCE on 25 September. The WVU team drilled a fully vertical wellbore in a 10.5-in thick rock sample in 27 minutes using the automated drilling rig that they designed and built. They included interactive drilloff tests to select optimal drilling parameters in near real time. Members of the team are Tawfik Elshehabi, Zachary Cox, Gbolahan "Bugzy" Idowu, Cody Smith, and Rachael Richard. Ilkin Bilgesu is the faculty advisor.
Directional surveys obtain the measurements needed to calculate and plot the 3D well path. Instruments for conducting directional surveys can be set up in several different variations, depending on the intended use of the instrument and the methods used to store or transmit survey information. Depending on the method used to store the data, there are film and electronic systems. Survey systems can also be categorized by the methods used to transmit the data to the surface, such as wireline or measurement while drilling (MWD). Magnetic sensors must be run within a nonmagnetic environment [i.e., in uncased hole either in a nonmagnetic drill collar(s) or on a wireline].
Having steered away from the congestion of the surface section, the main part of the well path through the overburden is specifically designed to put the well in the best possible position for penetrating the reservoir. There are three different overall shapes of the well, depending on the penetration requirements. In practice, these generic shapes will be modified by local conditions. Understanding the interaction between the 3D well trajectory and the formation stresses, particularly in overthrust areas, is vital to ensuring that the well can be drilled safely and efficiently. See Figure 1 for an illustration of these wellbores.
The most important factor in a sweep program is to carry it out in a proactive manner. It is much easier to keep the hole clean than it is to try to clean it up after solids buildup has occurred. Hole cleaning depends on fluid type. When wells are drilled with invert oil emulsion systems, cuttings tend to be harder, more competent, and better defined than in water-based mud (WBM). This method allows the cuttings to be removed from the wellbore more readily.