Home / 2008 / May/June (page 2)

May/June

Innovative systems enhance ability to achieve selective isolated production in horizontal wells

By Katie Mazerov, contributing editor The harsh reality of the oil and gas industry today lies in complicated horizontal labyrinths of tight twists and angles, in multiple layers of sand and shale. Production in this changing and challenging landscape has taken on a whole different meaning as the industry has had to find new methods for selectively isolating and extracting oil and gas from the now-commonplace complicated wells. The conventional way to achieve selective isolation production in horizontal wells was to case, cement and perforate multiple zones to control flow and increase reservoir drainage, explained Ed Wood, product line manager wellbore isolation at Baker Oil Tools. But the process was complicated, time-consuming and costly, and required the use of explosives ...

Read More »

Mesophase technology leads to new fluids for cased hole remediation, optimized displacement

Four or five years ago, Baker Hughes Drilling Fluids (BHDF) was asked by a major operator to develop a fluid that would destroy oil-based mud filter cake depositions for water injection applications. What resulted from their R&D effort was MICRO-WASH, which has been commercially available for about a year. It is based on mesophase technology, a chemistry developed by BHDF that can solubilize oil on contact and water-wet all damaged surfaces. Field results have indicated that MICRO-WASH can significantly improve water-injection rates or increase hydrocarbon recovery to more clearly define the value of a reservoir. BHDF recently launched two more mesophase systems: MICRO-CURE, a cased hole remediation system to remediate damage in the perforation zone, and MICRO-PRIME, a displacement fluid ...

Read More »

Operators raise downhole fluids expectations as they push boundaries with HPHT, ERD wells

For drilling fluid companies, working on today’s ERD wells is often like “playing on the knife’s edge,” said Nick Braley, director of technology at Baroid. Management of the equivalent circulating density (ECD) is critical on extended-reach drilling (ERD) wells, and that has evolved into a tough balancing act on wells with very narrow windows between pore pressure and fracture gradient. “You don’t want the well to kick so you stay above pore pressure. At the same time, you don’t want to fracture the formation and induce losses,” he said. “Operators are starting to push the horizontal displacement of their ERD wells to a degree that is testing the limits of current technology. From a fluids perspective, we’re being asked to ...

Read More »

Complex well profiles in ERD, ultra-ERD push for extended capabilities in drill pipe performance

By Lou Elliott, Vincent Bouchad, Jean Boulet, Anthony Monnet, VAM Drilling The advances in drilling technology required to drill ultra-deep and ultra-extended-reach wells is not reserved to rig capability. Drill pipe performance factors, high-torque connections and hole cleaning also can become limitations in extending the well envelope. Meeting the performance requirements imposed by these deepwater, hostile environments and extreme well profiles is challenging for any drillstring manufacturer. Deeper and more deviated wells require a drillstring with increased tensile load capability, greater torque capacity and a higher strength-to-weight ratio to overcome high frictional drag forces and improve hydraulic performance, rate of penetration, control of the well trajectory and hole cleaning. Torsional Yield Strength Extended-reach drilling (ERD) has been used successfully both ...

Read More »

What really happens to high-strength drill pipe after exposure to sour gas environment?

By Spoerker, H.F., Havlik, W., OMV E&P; Jellison, M.J., GrantPrideco Sour gas and high-strength steel are generally accepted to be incompatible. However, when drilling beyond 20,000 ft, S135 and higher steel grades become necessary to support their own weight, and due to the elevated downhole pressures in the range of 15-20 ksi, even minimal concentrations of H2S result in partial pressures that are considered hostile for these steel grades. This article presents initial results from a joint industry project exposing S-grade drill pipe samples to various H2S concentrations in temperature ranges from 70-170°C and exposure times of 1-3 hr, representing typical conditions when circulating a gas kick to surface. Test conditions have been designed to closely re-create actual downhole conditions. ...

Read More »

Multi-technical MPD concept, comprehensive planning extend HPHT targets on Kvitebjorn

By Svein Syltøy, Svein Erik Eide, Steinar Torvund, Per Cato Berg, StatoilHydro; Tore Larsen, Helge Fjeldberg, KCAD Norway; Knut Steinar Bjørkevoll, SINTEF; John McCaskill, Expro Power Chokes; Ole Iacob Prebensen, M-I Swaco; Eric Low, Think-Well Kvitebjørn is located in the Northern North Sea on the Norwegian Continental Shelf, southeast of the Gullfaks Field (Figure 1). It is classified as a HPHT gas condensate field. The reservoir consists of sandstones in the Mid-Jurassic Brent group and lower Jurassic). The top reservoir is at approximately 4,070 m TVD. Early production during development drilling has induced pressure depletion, creating a convergence between pore pressure and fracture pressure in the reservoir. The initial pore pressure was 775 bar (1.93 SG), and fracture pressure was ...

Read More »

High-torque top drives enhance drilling in shallow, long-reach horizontal and deep vertical wells

By Ron Pettapiece, Ensign Energy Services, and Barry Beierbach, Tesco Corp When drilling shallow extended-reach horizontal wells such as steam injection wells to produce heavy oil sands in Alberta, Canada, use of a top drive drilling system is not only a requirement, it’s necessary to have the highest torque available. Some of the wells can be only 1,500 ft total vertical depth (TVD), but they can also be several miles long at virtually 90° from vertical. Drilling contractors do not necessarily need the high hookload capacity that was part and parcel of high-torque top drives of the past. The top drive’s rated weight capacity doesn’t have to be high due to the horizontal nature of the wells, but high-torque capacity ...

Read More »

Mixed fleet approach to land drilling allows rigs to perform

By Ronald Buell, Atlas Copco Drilling Solutions Setting Up Pipe Handling There’s an old adage in the oil patch: “If a rig’s drill isn’t turning to the right, it isn’t making money.” If you consider what a rig does from the time it’s mobilized to reach a location until it is moved to the next location, there is much time and money spent on non-drilling functions. Still, these complex and time-consuming non-drilling activities are necessary for achieving productive drilling. Until recently, drilling a well was considered a continuous process where a single rig was employed to drill from the surface to TD. In reality, wells are drilled and completed in segments, and each of these well segments requires different rig ...

Read More »

US land drilling kicks into high gear, prepares for brisk year

Last year appeared to be a “period of pause” for US land drilling contractors as the industry absorbed a significant number of new and refurbished rigs into its fleet, said Ron Hale, Grey Wolf Drilling senior vice president international operations. Although operators didn’t slow down their drilling programs, the additional units that came into the US fleet simply lifted supply above demand. As a result, some rigs got stacked, and dayrates softened. But that period of pause is over now, and it looks like 2008 – after a steady first quarter – is ready to make some noise. “We’re feeling it. I think we’re going to grow some,” said John Baer, mid-continent operations manager for Helmerich & Payne, of his ...

Read More »

Casing-while-drilling successfully applied in Canadian Arctic permafrost environment

By H. Vrielink, BP; J.S. Bradford, Chevron; L. Basarab, Tesco Corp; C.C. Ubaru, Hughes Christensen The JV operator was looking for a combination of technologies to optimize drilling in Canada’s Mackenzie Delta region. The area is characterized by a permafrost section, up to 2,000 ft (609 m) thick, dominated by unconsolidated silt with freshwater ice ranging from 60% volume to pure ice layers. Historically, mechanical heat input has melted the frozen layer, resulting in increased hydrates/shallow gas risks, extreme hole enlargement/cleaning problems, rig support issues, wellbore instability, stuck pipe, hydraulic isolation, and environmental impact issues. Optimizing drilling operations through the shallow section is critical to maximizing the number of wells that can be drilled with the available rigs in this ...

Read More »