scholarly journals STUDY OF THE DYNAMICS OF THE TRAVELING BLOCK-CROWN BLOCK MECHANISM OF THE DRILLING RIG WITH TWO ACTIVE DRAWWORKS

2021 ◽  
Vol 2(73) (1) ◽  
pp. 73-81
Author(s):  
Claudia Niculae ◽  
Maria Tănase

"In the hoisting equipment, the hoisting or lowering of the load at the hook is done with the drilling cable that connects the sheaves from the crown-block and those from the travelling-block. Failure of the drilling line can have catastrophic effects, hence it is very important to evaluate as accurately as possible the values of the lines tensions, so that during the drilling operations they do not exceed their tensile limits. The present paper deals with the study regarding the dynamics of the of the travelling block- crown block mechanism with two active drawworks and is establishing the expressions for calculation of the tensions from the drilling lines, depending on the load applied at the hook during both hoisting and lowering operations. The calculation is performed for the case of the travelling block-crown block mechanism provided with 3 respectively 4 sheaves and the values of the lines tensions for a hoisting equipment with two active drawworks are compared with the values for the conventional hoisting equipment. "

Author(s):  
Alexandre Diezel ◽  
Germain Venero ◽  
Victor Gomes ◽  
Leandro Muniz ◽  
Rafael Fachini ◽  
...  

With the extension of the offshore drilling operations to water depths of 10,000 ft and beyond, the technical challenges involved also increased considerably. In this context, the management of the riser integrity through the application of computational simulations is capital to a safe and successful operation — particularly in harsh environments. One of the main challenges associated with keeping the system under safe limits is the recoil behavior in case of a disconnection from the well. The risk that an emergency disconnect procedure can take place during the campaign is imminent, either due to failure of the dynamic positioning system or due to extreme weather in such environments. Recent work [1] in the field of drilling riser dynamic analysis has shown that the recoil behavior of the riser after a disconnection from the bottom can be one of the main drivers of the level of top tension applied. Tension fluctuations can be very large as the vessel heaves, especially in ultra-deep waters where the average level of top tension is already very high. In order to be successful, a safe disconnection must ensure that the applied top tension is sufficient for the Lower Marine Riser Package (LMRP) to lift over the Blow-Out Preventer (BOP) with no risk of interference between the two. This tension should also not exceed a range in which the riser will not buckle due to its own recoil, that the telescopic joint will not collapse and transfer undesirable loads onto the drilling rig or that the tensioning lines will not compress. A good representation of such behavior in computational simulations is therefore very relevant to planning of the drilling campaign. A case study is presented herein, in which a recoil analysis was performed for a water depth of 11,483ft (3,500m). Numerical simulations using a finite element based methodology are applied for solving the transient problem of the riser disconnection in the time domain using a regular wave approach. A detailed hydro-pneumatic tensioning system model is incorporated to properly capture the effect of the anti-recoil valve closure and tension variations relevant during the disconnection. A reduction of conservativism is applied for the regular wave approach, where the maximum vessel heave likely to happen in every 50 waves is applied instead of the usual maximum in 1000 waves approach. ISO/TR 13624-2 [4] states that using the most probable maximum heave in 1000 waves is considered very conservative, as the event of the disconnection takes place in a very short period of time. The challenges inherent to such an extreme site are presented and conclusions are drawn on the influence of the overall level of top tension in the recoil behavior.


Author(s):  
Daiyan Ahmed ◽  
Yingjian Xiao ◽  
Jeronimo de Moura ◽  
Stephen D. Butt

Abstract Optimum production from vein-type deposits requires the Narrow Vein Mining (NVM) process where excavation is accomplished by drilling larger diameter holes. To drill into the veins to successfully extract the ore deposits, a conventional rotary drilling rig is mounted on the ground. These operations are generally conducted by drilling a pilot hole in a narrow vein followed by a hole widening operation. Initially, a pilot hole is drilled for exploration purposes, to guide the larger diameter hole and to control the trajectory, and the next step in the excavation is progressed by hole widening operation. Drilling cutting properties, such as particle size distribution, volume, and shape may expose a significant drilling problem or may provide justification for performance enhancement decisions. In this study, a laboratory hole widening drilling process performance was evaluated by drilling cutting analysis. Drill-off Tests (DOT) were conducted in the Drilling Technology Laboratory (DTL) by dint of a Small Drilling Simulator (SDS) to generate the drilling parameters and to collect the cuttings. Different drilling operations were assessed based on Rate of Penetration (ROP), Weight on Bit (WOB), Rotation per Minute (RPM), Mechanical Specific Energy (MSE) and Drilling Efficiency (DE). A conducive schedule for achieving the objectives was developed, in addition to cuttings for further interpretation. A comprehensive study for the hole widening operation was conducted by involving intensive drilling cutting analysis, drilling parameters, and drilling performance leading to recommendations for full-scale drilling operations.


2020 ◽  
pp. 1-11
Author(s):  
Pavel Talalay ◽  
Youhong Sun ◽  
Xiaopeng Fan ◽  
Nan Zhang ◽  
Pinlu Cao ◽  
...  

Abstract Drilling to the bedrock of ice sheets and glaciers offers unique opportunities for examining the processes occurring in the bed. Basal and subglacial materials contain important paleoclimatic and paleoenvironmental records and provide a unique habitat for life; they offer significant information regarding the sediment deformation beneath glaciers and its effects on the subglacial hydraulic system and geology. The newly developed and tested Antarctic subglacial drilling rig (ASDR) is designed to recover ice and bedrock core samples from depths of up to 1400 m. All of the drilling equipment is installed inside a movable, sledge-mounted, temperature-controlled and wind-protected drilling shelter and workshop. To facilitate helicopter unloading of the research vessel, the shelter and workshop can be disassembled, with individual parts weighing <2–3 tons. The entire ASDR system weighs ~55 tons, including transport packaging. The ASDR is designed to be transported to the chosen site via snow vehicles and would be ready for drilling operations within 2–3 d after arrival. The ASDR was tested during the 2018–2019 summer season near Zhongshan Station, East Antarctica. At the test site, 2-week drilling operations resulted in a borehole that reached bedrock at a depth of 198 m.


Author(s):  
Arne Gu¨rtner ◽  
Ove Tobias Gudmestad ◽  
Alf To̸rum ◽  
Sveinung Lo̸set

Recent discoveries of hydrocarbons in the shallow waters of the Northern Caspian Sea arise the need for intensive drilling activities to be carried out in the near future in order to explore the potentials. Experience with mobile drilling units in the seasonally ice infested waters solely originates from the current drilling campaign of the Sunkar drilling barge at Kashagan and Kalamkas. However, with increased drilling activities upcoming, innovative drilling concepts are desirable due to the objective of maintaining drilling operations during the ice period with conventional non-ice-resistant drilling platforms. Hence, this paper suggests the employment of external Shoulder Ice Barriers (SIBs) to protect a conventional jack-up drilling rig from the hazards of drifting ice in shallow water. The SIB’s design is suggested to increase the ice rubble generation at the ice facing slope and thereby provide sufficient protection from drifting ice impacts. The modular concept of the SIB makes it possible to deploy each module in a floating mode to site, whereupon they are ballasted and connected to each other, forming a sheltered position for the jack-up. Subsequent to the termination of the drilling campaign the SIB modules may be retrieved by de-ballasting and tow out, without having significant impact on the environment. This paper presents, on a technical feasible level, the concept of ice protection in shallow water by means of SIBs.


2021 ◽  
Author(s):  
Daniel Lemos ◽  
Jean Marins ◽  
Raone De Lima

Abstract This paper presents an innovative concept to run Electrical Submersible Pumps (ESP) and upper completion utilizing dual derrick drillship rigs in deep water wells. The availability of a second deck to assemble, test and rack long assemblies brings the possibility to conduct a safer, efficient and reliable operation. The experience in Brazil running complex completions and high horsepower ESPs shows how important is to implement initiatives to reduce rig time. The main objective of the new process is to have every completion tool readily available in the drilling deck, requiring minimum time to connect it to the completion string. In the standard process, the tool sits in the pipe deck until completion string reaches its set position and only then the equipment is brought into the rig floor to be serviced and made up to the completion string. The methodology to assemble ESP and completion tools offline in the auxiliary derrick was developed in partnership with the operator, the service company, and the drilling rig contractor. The offline preparation concept was considered as part of the completion design phase analyzing every step of the upper completion run, looking for efficiency improvement and reduced total rig time. The modern automated pipe handling system was used to manipulate the long and heavy assemblies from the auxiliary deck to the racking system and from the racking system to the main deck without any safety concern, and with minimal human intervention. Eight deep-water operations were completed in Brazil using the new concept and the results brought important rig time reduction in the upper completion running time. The tools that were part of the completion included DHSV, permanent downhole gauges, chemical injection valves, 1600 HP ESP system and tubing test valves. The new process allows the team to service equipment without the usual operation rush reducing installation related failure therefore increasing equipment reliability. The methodology presented on this paper contributes to oil industry as a field-proven reference for offshore ESP and completion deployment technique reducing HSE exposure and total well construction cost. This is particularly important for deep and ultra-deepwater projects which are associated with high intervention costs. Dual derrick rigs were designed with focus to improve drilling operations and after the new process development, the modern robotized machinery empowers ESP and completion activities with improved efficiencies.


Author(s):  
Scott Benson ◽  
Massimiliano Russo ◽  
Eivind Rasten ◽  
Ward Avery ◽  
Paul LeGrow ◽  
...  

In recent years, lower oil prices have forced many oil companies to reduce capex costs by revitalizing brown fields, rather than developing new green fields. At the same time, the offshore drilling rig market has seen many old rigs, typically used for shallow water operations, being scrapped, leaving new generation, deep and ultra-deep water MODUs as the only viable option for new drilling campaigns. Based on the above, wellhead fatigue on older assets, especially in harsh, shallow water environments, has started to gain a central role during the planning phases of workover and intervention operations. In recent years, Suncor Energy began investigating an extension to its Terra Nova field, which began production in 2002. The field uses subsea wells tied back to an FPSO which is moored in 95m of water off Canada’s eastern Grand Banks, an area frequented by icebergs. Drilling operations for the field extension were planned to commence in summer 2017, and continue with a year-round drilling campaign using a Cat 6 MODU. Since the extension would involve sidetracks and interventions from existing wellheads, a series of wellhead fatigue studies were undertaken using a variety of industry recognized methodologies [1] to understand the levels of fatigue accumulation. Although there has been no evidence of wellhead fatigue damage, Suncor chose to take a very prudent and proactive approach, aimed at minimizing fatigue, and maintaining fatigue life for potential future drilling operations. An Instrumented Wellhead Load Relief (iWLR) system was installed, which is designed to restrain BOP motions, thereby reducing the wellhead loads considerably. The load reduction system virtually eliminates additional fatigue accumulation for the planned operations. Additionally, the instrumentation system enables the precise monitoring and tracking of loads applied at the wellhead for future analysis. This paper describes the engineering challenges needed to develop and install the iWLR system in a harsh, shallow water, arctic environment. This area is characterized by very stiff soils pitted with iceberg scours, where subsea equipment must be protected within 10m deep excavated drill centers to prevent iceberg collisions in the relatively shallow water. Additionally, the paper describes how the instrumentation system was integrated with the BOP MUX cable communication system, for the first time, to enable real time monitoring of BOP motions using high accuracy gyroscopes and load cells which monitor dynamic iWLR tether forces. A topside data gathering and processing system was developed to present wellhead loads based on the indirect method, with new algorithms established to account for the tether forces. Finally, the paper presents some preliminary high-level results, showing the efficiency of the system based on measured data.


1993 ◽  
Vol 33 (1) ◽  
pp. 343
Author(s):  
Derek C. Morrow ◽  
Nick E. Jackson

The Drilling Facilities Package designed and developed by Atwood Oceanics Australia Pty. Ltd. for operation on Woodside Offshore Petroleum Pty. Ltd.'s Goodwyn 'A' Platform will break new ground in the development and application of offshore modular drilling rig technology when commencement of offshore drilling is achieved. These facilities are among the largest, specifically designed, offshore demountable drilling rigs in the world today.Initially, Woodside performed sufficient engineering to determine a design specification for the Drilling Facilities which detailed the types of equipment necessary and the final performance characteristics required by the finished facility to drill the Goodwyn 'A' production wells.Following award of the Drilling Facilities Contract to Atwood Oceanics in 1989, Woodside's role was essentially related to technical interface and contract administration management. The responsibility for the design, fabrication, commissioning and operation of the Drilling Facilities lay with Atwood Oceanics.The Drilling Facilities consist of fifty-two (52) small modules, each weighing up to 105 tonne. These modules are assembled into three (3) major structural packages, these being the Drilling Support Facilities, weighing some 1300 tonne, the Sub-Base weighing 1100 tonne and the Derrick weighing 260 tonne. Total operating weight of the facilities will exceed 4500 tonne.The modular design of these facilities was developed by Atwood Oceanics from previous modular rig design of relatively simple facilities and technical scope, up to the high capacity, technical complexity and flexibility in design demanded for operation on the Goodwyn 'A' Platform. Following the issue of the Cullen Report on the Piper Alpha Disaster, extensive control and monitoring safety systems were included in the design. These systems have had an adverse impact on the modular concept due to the large increase in electrical interfaces, however the modular concept remains sound and viable.Modular rig design has allowed a Drilling Facility to be developed which has accrued savings in design, fabrication, fit-out, transport and installation and has resulted in reduced overall installed weight. These savings are real and demonstrable when compared with conventional large-module drilling rig packages of similar scope and complexity. Unlike its North Rankin 'A' development, Woodside elected to have the Drilling Facilities for Goodwyn 'A' designed, procured, fabricated and commissioned by an experienced drilling contractor, who will then operate and maintain the rig during the drilling phase (P.Scott et al., 1991). Woodside will realise substantial cost savings at the point when the facilities are installed and ready to drill. Further savings will accrue during drilling operations by allowing the drilling contractor more autonomy and responsibility (eg. maintenance of the complete drilling facilities will be by contractor personnel).The relative ease of removal of the facilities and potential for re-use on other installations will generate additional significant cost benefits in the future.The Drilling Facilities are state-of-the-art in their applied technology and are capable of year-round, self-contained operation for the drilling of highly deviated, long reach wells of up to 72° deviation from the vertical and up to 7000 m along hole depth.This paper provides an overview of the design, fabrication, fit-out, onshore commissioning, transport and installation of the modules which comprise the Goodwyn 'A' Drilling Facilities, for which Atwood Oceanics were awarded a Commendation for a High Standard of Engineering Achievement at the Institution of Engineers, Australia 1992 Engineering Excellence Awards.


1984 ◽  
Vol 21 (01) ◽  
pp. 1-11
Author(s):  
Sherman B. Wetmore ◽  
Harold D. Ramsden

This paper describes a unique system that can provide an alternative to gravel islands as a means of supporting drilling operations in shallow Arctic waters. The Concrete Island Drilling System (CIDS) is composed of modular concrete "bricks" stacked one on top of the other which, in turn, support a barge-mounted drilling rig. Sequentially stacking these modules provides a great deal of flexibility in siting the modules in water depths of 18 to 52 ft. The modules incorporate an efficient concrete "honeycomb" structural system that offers inherent longitudinal, transverse and torsional strength. The superior strength of the CIDS, coupled with its massive ballasted weight, enables it to withstand the ice pressures prevalent in the landfast ice areas of the Arctic. Several key features of the CIDS make it a unique and economically advantageous exploratory drilling platform. Because it is modular, the CIDS reduces construction and transportation problems and allows the use of various configurations that can be modified to suit the water depth requirement. No dredging or gravel-hauling activity is associated with the CIDS since the gravity load is achieved by merely ballasting the modules with seawater. The entire system, with the drilling rig intact, can be relocated by pumping out the saltwater ballast and towing the CIDS to a new site. No rig demobilization or "under-dredging" of caisson fill is required. The use of concrete insures a long-lived structure that can be reused on many wells.


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