In-situ combustion requires standard field equipment for oil production, but with particular attention to air compression, ignition, well design, completion, and production practices. Air-compression systems are critical to the success of any in-situ combustion field project. Past failures often can be traced to poor compressor design, faulty maintenance, or operating mistakes. See Compressors for a detailed discussion of compressors and sizing considerations. Other discussions are available in Sarathi.
The bearing, seal, and lubrication systems of a roller cone bit are important aspects of bit life and efficiency. Roller cone bearing systems are designed to be in satisfactory operating condition when the cutting structure of the bit is worn out. To achieve this standard of bearing performance, modern goals for seal and bearing system life are 1 million or more revolutions of a bit without failure, as opposed to 300,000 or fewer in the recent past. To achieve this goal, research into bearing, seal, and lubricant designs and into materials that improve seal and bearing life is ongoing. Roller-cone bits primarily use two types of bearings: roller bearings and journal bearings, sometimes called friction bearings.
During drilling operations, a pipe is considered stuck if it cannot be freed from the hole without damaging the pipe, and without exceeding the drilling rig's maximum allowed hook load. Pipe sticking can be classified under two categories: differential pressure pipe sticking and mechanical pipe sticking. Complications related to stuck pipe can account for nearly half of total well cost, making stuck pipe one of the most expensive problems that can occur during a drilling operation. Stuck pipe often is associated with well-control and lost-circulation events--the two other costly disruptions to drilling operations--and is a significant risk in high-angle and horizontal wells. Drilling through depleted zones, where the pressure in the annulus exceeds that in the formation, might cause the drillstring to be pulled against the wall and embedded in the filter cake deposited there (Figure 1).
Liu, Yunfeng (China University of Petroleum) | Qiu, Zhengsong (China University of Petroleum) | Zhong, Hanyi (China University of Petroleum) | Meng, Meng (University of Tulsa) | Zhao, Xin (China University of Petroleum) | Nie, Zhen (CNPC Research Institute of Petroleum Exploration and Development) | Huang, Weian (China University of Petroleum)
Lubricants used in the Water based mud (WBM) can solve the high torque and drag problems encountered in extended reach drilling operations. The fast development in the deep & ultra-deep drilling technology puts forward higher requirements for the anti-temperature performance of WBM lubricants which beyond the ability of the commercial lubricants. How to fulfill the gradually restrictive environmental regulations and lower the total cost has already been a tough task for the drilling fluid designers.
In this paper, a novel lubricant SDL-1 as synergistic application of optimized waste by-product vegetable oil MVO-3 and expandable graphite GIC was described. The physicochemical properties of MVO-3 and GIC were analyzed separately. In order to form a stable synergetic system, the type and amounts of the dispersants and emulsifiers were optimized. Then technological development process of lubricant SDL-1 was introduced in details. And comprehensive evaluations of SDL-1 were conducted according to corresponding technical standards and the synergistic mechanism of it was revealed.
Development of the novel lubricant as synergistic application of waste by-product vegetable oil and expandable graphite affords a hopeful solution to solve the high torque and drag problems during drilling process. The substantial reduction in drilling costs with valuable application prospect makes the new developed lubricant more attractive. Furthermore, further benefits could appear in the economic development of relevant industries as the locally waste by-product vegetable oil was used in developing the novel lubricant.
With the objective of increasing productivity and achieving an economically sustainable development of the non-conventional reservoirs in Argentina, the oil and gas (O&G) energy companies are focused on drilling horizontal wells with lateral extensions between 2500 m (8,200 ft) to 3000 m (9,840 ft) in length. In order to produce commercial volumes of hydrocarbons, it is mandatory to fracture-stimulate multiple zones. The "plug and perf" method continues to be the most common completion technique in the field. Once the stimulation is completed, a coiled tubing (CT) milling operation is undertaken to remove the frac plugs. Critical to achieving a successful operation is reaching total depth (TD) in the well with the coiled tubing. The precise determination of the operational coefficient of friction (CoF) between the coiled tubing string and the production casing, could be the difference between failure and success, affecting both the technical and economical results of the project. The goal of this paper is to share the lessons learned after more than forty extended reach operations and the experience earned on the utilization of real time simulations to define both, the tensile load exerted for an extended reach tool and the coefficient of friction found during coiled tubing operations. Also demonstrate, by analyzing real life applications, how the implementation of this technology and new working methodology, allows to anticipate deviations with respect to the "normal" values of friction, achieve a better understanding of the influence of solids in the completion to the coefficient of friction and obtain a more efficient use of the metal-metal lubricant utilized during the milling operations.
The successful development of an oil and gas field relies upon the application of technology. Utilizing data-driven results improves drilling efficiency in extended-reach wells. Horizontal drilling of these wells is necessary for oil recovery due to the very low permeability of the reservoir and the presence of natural vertical fractures found in the Williston Basin. The reservoirs within the Williston Basin are generally tight with a relatively high pore pressure. A novel additive used during the drilling phase of the well was implemented and improved for coil tubing milling and cleanout procedure.
Coil tubing application requires the use of robust fluid products due to the demanding environment. The novel additive was used to increase the lubricity improving friction on metal to metal contact where excess torque and drag led to the use of multiple tool runs and several short trips to decrease the drag forces.
Novel water-based drilling fluid enhancer used in varying concentrations maximizes the performance, reducing the need for excessive short trips and an increase in tool life. This paper will highlight the planning phase for the engineering design, the equipment used, friction factor matching, and the challenges encountered using the additive during coil tubing applications. Operators have seen noticeable reductions in days reducing the amount of flat time with prior conventional application. The application case history shows introduction in the Williston Basin and lessons learned when introduced into the Permian.
For over 20 years, F&L Asia has remained the preferred media choice for industry giants such as Chevron, ExxonMobil, Shell, SK Lubricants, S-Oil, Lubrizol, Infineum, Chevron Oronite, Afton Chemical, BASF, Evonik Industries, Tianhe Chemicals and many more. This empowers them to increase their brand awareness and establish, promote and nurture fluid industry connections globally. Each year, F&L Asia produces F+L Week, the industry conference and exhibition premier event. A sounding board for the latest developments in base oils, lubricants, fuels and additives, F+L Week attracts the very best amongst top industry scientists, market trend setters and decision makers from all around the planet to its economic epicentre in Asia. OIL & GAS TODAY is a quarterly publication focusing on the latest news and events in the oil & gas and petrochemical industries in Thailand and the ASEAN region.
Ernens, Dennis (Shell Global Solutions International BV, University of Twente) | Peréz-Ràfols, Francesc (Luleå University of Technology) | Hoecke, Dennis Van (OCAS NV) | Roijmans, Roel F. H. (Shell Global Solutions International BV) | Riet, Egbert J. van (Shell Global Solutions International BV) | Voorde, John Vande (OCAS NV) | Almqvist, Andreas (Luleå University of Technology) | Rooij, Matthijn Bas de (University of Twente) | Roggeband, Serge Mathieu (Shell Global Solutions International BV) | Haaften, Willem Maarten Van (Shell Global Solutions International BV) | Vanderschueren, Marc (OCAS NV) | Thibaux, Phillipe (OCAS NV) | Pasaribu, Henry Rihard (Shell Global Solutions International BV)
Metal-to-metal seals are used in connections of casing in oil and gas wells. This paper describes the mechanisms of sealing of metal-to-metal seals as investigated using an experimental set-up and a sealability model. Experiments were conducted for a variety of thread compounds and applied pin/box surface coatings. The results were used to validate a numerical model for sealability. The stochastic model couples a contact mechanics model with a flow model and takes the influence of all the surface topography features into account. Once validated, the model was used together with the experimental results to explain the sealing mechanisms of metal-to-metal seals.
The sealing configuration is a face seal with an R=80 mm round-off radius pressing against a flat. The face seal specimens were manufactured from P110 tubing. The used test set-up is designed for investigating only the metal-to-metal seal of the connection. The set-up can carry out rotary sliding under constant load to simulate surface evolution during make-up and subsequently perform a leakage test. The sealing limit is determined by applying 700 bar fluid pressure and then gradually reducing the normal force until leakage is observed. The data is subsequently used to validate a previously published model.
The results indicate a strong dependence of the type of thread compound used on the onset of leakage. The thread compound affects the amount of wear and thus changes the surface topography of the interacting surfaces. It is shown that the sealability model is capable to predict the onset of leakage within the experimental accuracy. The model shows further that certain surface topographical features improve the sealing performance. Namely, a turned against a flat surface topography leads to highly localized contact areas, which in turn yields the best sealing performance.
The combination of experimental data with the validated model leads to much deeper insights for the sealing mechanisms than what could be obtained using either on their own.
Ernens, Dennis (Shell Global Solutions International BV, University of Twente) | Westerwaal, Diana (Shell Global Solutions International BV) | Roijmans, Roel F. H. (Shell Global Solutions International BV) | van Riet, Egbert J. (Shell Global Solutions International BV) | Daegling, Stefan (Shell Global Solutions Germany GmbH) | Wheatley, Alan (Shell International Petroleum Company Ltd.) | Worthington, Edward (Shell Global Solutions Germany GmbH) | Kramer, Henk (Nederlandse Aardolie Maatschappij B.V.) | Van Haaften, Willem Maarten (Shell Global Solutions International BV) | De Rooij, Matthijn Bas (University of Twente) | Pasaribu, Henry Rihard (Shell Global Solutions International BV)
Thread compounds play an important role in the sealing ability of casing connections in the oil and gas industry. Next to their lubricating role during assembly, most of these thread compounds make use of nonbiodegradable or persistent particle additives to aid in the sealing ability. Soon, these additives need to be replaced by benign alternatives as agreed in the proceedings of the Oslo-Paris Commission. This is, however, a challenge in high temperature (>150°C) well environments. This paper presents an investigation of the high temperature failure mechanisms of thread compounds with the aim to develop biodegradable high temperature resistant thread compounds. To this end, the performance of commercially available, environmentally acceptable thread compounds was investigated with thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), high temperature rheometry and high temperature pin-on-disc experiments. The compounds are assessed on their stability, consistency, lubricity, and the resulting wear at high temperature. The results indicated that, without exception the commercially available thread compounds investigated in this study fail by adhesive and/or abrasive wear at around 150 degrees Celsius because of thermally induced degradation. To remedy this and to validate the mechanisms, a prototype thread compound was developed which exhibits strong film forming. The conclusion is that a successful high temperature resistant environmentally acceptable thread compound can likely be developed. The key property of this thread compound should be the ability to form a tribofilm during make-up which protects the surface at a later stage when the lubricant has lost its consistency and the base oil is fully evaporated.