Horizontal and Complex-Trajectory Wells
Following the downturn, the number of horizontal wells drilled this year has fallen dramatically compared with previous historic levels. In these difficult times, attention to cost reduction through relentless optimization of all segments, from drilling to completions, has never been so important. Horizontal-well costs have decreased significantly over the last few years thanks to many lessons learned. In unconventional plays, multiple solutions have been implemented and tested in well construction, casing design, hole size, bottomhole assemblies (BHAs), directional systems, drillpipe, oscillation techniques, drill bits, well trajectory, and pad drilling, with the main goals being greater efficiency and reduction of costs.
On the drilling side, operators have been able to find the optimal drilling system to drill the curve and the lateral with the same BHA in just a few days. Have we reached a plateau? Not yet. Can we optimize more? Yes, absolutely. In unconventional wells, the trend is now to increase the horizontal length to 15,000 ft and, further, to increase the recoverability per foot of lateral. There is probably a technical and economic limit to this, but the industry has kept pushing these limits further. The role of digital technologies is increasing, and this enables oilfield performance improvements. Indeed, drilling data easily acquired now with electronic drilling recorders have revolutionized the possibility of visualization, monitoring, and analysis in real time. The attention recently has been on trying to use computer modeling to guide the directional-drilling process. Guidance systems in two or three dimensions are now helping the directional driller in real time to find the best possible well path to reduce tortuosity and maximize rate of penetration and possibly production. Data coming from the drilling job are now reused by completion teams to optimize the position of the hydraulic-fracturing stages to maximize production. The main idea consists of calculating the mechanical specific energy at the bit (derived from operating parameters) to estimate unconfined compressive strength of the rock, which is a valuable mechanical rock property for reservoir evaluation, eventually to map zones with high potential for fracturing.
Thanks to the analysis of previously drilled and completed wells (microseismic fracture mapping, reservoir modeling, and production analysis), the industry is moving toward optimal lateral and vertical spacing between two horizontal wells to get the greatest recovery of hydrocarbons in place.
On the completion side, the same data accumulated over the last few years have enabled operators to compare fairly the two typical completion systems used in unconventional plays (fracturing sleeve with activated ball or plug-and-perforate techniques) to better evaluate them and select one method over another.
These examples illustrate just a few of the numerous advances made in horizontal and complex-trajectory wells and demonstrate that, despite this historic downturn, the oil and gas industry has kept innovating and optimizing to bring more-efficient solutions to the table.
This Month's Technical Papers
Recommended Additional Reading
SPE/IADC 180652 Improving Directional Survey Accuracy Through Real-Time Operating Centers by Shawn DeVerse, Surcon, et al.
SPE/IADC 178885 Multilaterals in the Mississippi Lime by Robert Meize, SandRidge Energy, et al.
SPE/IADC 178875 Team Approach to Horizontal-Drilling Optimization in the Marcellus Delivers Record-Setting Performance by Denise Azuaga Livingston, Baker Hughes, et al.
Horizontal and Complex-Trajectory Wells
Stephane Menand, SPE, President, DrillScan US
01 November 2016
Drilling for Miles in the Marcellus: Laterals Reach New Lengths
Range Resources' drilling head talks about how the company went from drilling the shortest laterals in the Marcellus to the longest and why.
Unlocking Egypt’s Unconventional-Resource Potential
The Apollonia tight-gas chalk play is located in the Abu Gharadig Basin in the Western Desert of Egypt. This has long been ignored as a gas play in the overburden, while the Jurassic and Cretaceous oil fields deeper in the basin have been explored and developed.
Underbalanced Drilling With Coiled Tubing in Marginal Shallow Wells
The complete paper describes a recent directional coiled-tubing drilling (DCTD) job completed for an independent operator in the Appalachian Basin.
Don't miss out on the latest technology delivered to your email weekly. Sign up for the JPT newsletter. If you are not logged in, you will receive a confirmation email that you will need to click on to confirm you want to receive the newsletter.
10 September 2018
14 September 2018
11 September 2018
17 September 2018
07 September 2018