Drilling & Completion Tech Digest

Total runs cementless completion in Congo using Welltec Annular Isolation

Welltec has announced the first deployment of a truly cementless completion in the Republic of Congo during Q2 2019. The completion was conducted by Total E&P Congo using the Welltec Annular Isolation (WAI) tool in open hole, building on the operator’s experience gained through previous deployment of the Welltec Annular Barrier (WAB) in the Moho North Albian field.

The WAI uses multiple metal expandable packers to provide long-length open-hole zonal isolation to replace the functions of traditional cement, leading to significant gains in efficiency in the overall well construction process.

It significantly reduces the free annulus space between the liner/casing and the open hole, which can be beneficial in highly layered reservoirs of varying permeability where selective production, stimulation or water shut-off is required.

In addition to the efficiency gains, the simplified well completions operations eliminated multiple operational risks associated with the cementing process in depleted and overpressured reservoirs.

Total E&P Congo was an early adopter of the WAB, which assisted in ensuring zonal isolation and annular sealing (liner to formation) during the development of the company’s major oil project in the Republic of Congo, according to Ronan Bouget, the Drilling and Completions Manager of Total E&P Congo. “The simplicity of the WAI enabled us to successfully deploy the technology the first time without operational issues,” Mr Bouget said.

The WAI was deployed as part of Total’s drive to reduce drilling expenditure while maintaining productivity in this highly heterogenous carbonate field. The Albian Asset team worked with Welltec to develop the technology. The operator plans to deploy the WAI in subsequent wells – especially those identified as high risk.

Circulation sub saves operator a wellhead jetting trip

A major North Sea operator recently improved its wellhead base jetting operations by deploying the DAV MX CircSub from Churchill Drilling Tools.

After drilling operations, the operator had to remove cuttings debris from its wellhead base prior to wellhead installation.  The local sea currents were not enough to wash away the cuttings naturally, and the operator wanted to avoid the cost of a dedicated jetting assembly run.

The operator decided to run the tool in the drill string. It stayed dormant through the drilling phase, then was activated using a smart dart to achieve the desired jetting bypass of 1,200 gal/min.

This high-velocity stream of fluid jetting through the CircSub’s four custom angled ports was powerful enough to remove the cuttings from the wellhead base. Just two 30-minute sweeps of the wellhead base cleared away all debris, enabling successful installation of the wellhead shortly afterwards.

This avoided the complexity of a dedicated cleaning trip.

This tool has been deployed on more than 2,000 occasions by 115 operators. Since its launch, it has withstood temperatures of 197°C, been activated at depths of more than 31,000 ft, managed fluid in excess of 19.5 lb/gal and LCM of 224 lb/bbl.

CARE introduces Canada’s first Tier 4 final service rig

CARE Industries, working with Wajax, an MTU distributor, has delivered Canada’s first service rig powered by Tier 4 final engines. As of 2018, diesel engines over 174-hp used in off-highway applications must meet Environment Canada and EPA Tier 4 final emissions standards.

MTU Series 60 engines had previously powered CARE Industries service rigs. To match the power range of the Series 60, the Tier 4-certified MTU Series 1100 was chosen. Wajax designed a service rig drop-in package that includes the Series 1100, transmission, control system and after-treatment system. It’s the only fully integrated Tier 4 drop-in package of its kind. The Series 1100 is the only Tier 4 engine in its power range that doesn’t require a diesel particulate filter.

The transition to the Tier 4-certified Series 1100 will not only reduce emissions but is expected to be at least 20% more fuel-efficient.

NOV manufactures world’s largest drawworks

National Oilwell Varco (NOV) recently announced that it completed the manufacturing of the world’s largest drawworks, the AHD-1700.

Recognizing that operators are preparing to explore high-pressure, high-temperature wells in the 20,000-psi pressure frontier, NOV knew that casing weights would be increasing as wells became longer.  Drawworks would be needed to handle the increased hookload and heave capacities.

The new drawworks, powered by seven motors, feature a maximum hookload of 1,700 tons and full heave compensation. The unit’s fast line pull comes in at 240,601 lb, while it has a maximum continuous power of 10,500 hp. Additionally, the maximum block travel is 205 ft at 16 lines and fourth layer.