In the world we know today, BOP performance is in the limelight all the way from the manufacturers to governmental levels. Greater performance objectives require higher testing standards. Testing and qualification of BOP equipment as dictated by API 16A involves facilities with the capability to test BOP's in multiple environments and operating scenarios. This paper will discuss the test set up for each type of test, the criteria for acceptance and the type of facility required to perform it. The types of tests to be discussed as defined in API 16A are fatigue testing, high temperature, low temperature, stripping, hang off, sealing characteristics, shear testing etc. The paper will also discuss some of the potential future testing requirements as well as the equipment required to perform it based on industry discussions of these requirements. Finally, the paper will discuss the process by which a multimillion dollar R&D lab was developed and operated from the ground up. It's not only about capability; it's about capacity. Applying manufacturing principles to the design and operation of an R&D Test facility achieved significant gains in the quality and output of tests performed. In summary, this paper will examine the needs of a modern BOP test facility and the methods used to deliver on those needs effectively.
Nwaoji, Charles O. (University of Calgary) | Hareland, Geir (University of Calgary) | Husein, Maen (University of Calgary Library - Swets) | Nygaard, Runar (Missouri University of Science & Tech) | Zakaria, Mohammed Ferdous (University of Calgary)
This paper introduces a novel LCM drilling fluid blend which has been used successfully in the laboratory to acheive wellbore strengthening results in permeable and impermeable formations for water based and invert emulsion (diesel oil) based drilling fluids.
Optimum combinations of standard LCM (graphite) and in-house prepared nanoparticles (NPs) (iron (III) hydroxide and calcium carbonate) have been established by running hydraulic fracture experiments on Roubidoux sandstone and impermeable concrete cores. Different blended fluids were used to prop open and seal fractures. The blends that gave the highest increase in fracture pressure with minimal distortion in mud rheological properties were selected for both drilling fluid type. The optimal fluid blend for water based mud was repeated using impermeable concrete core to test for consistency of result and possible application to shale wellbore strengthening.
The optimal blend (iron III hydroxide NPs) and graphite increased the fracture pressure by 1,668 psi or by 70% over the unblended water based mud with moderate impact on mud rheology. The optimal blend (calcium carbonate NPs) and graphite increased the fracture pressure by 586 psi or by 36% over the unblended invert emulsion mud with moderate impact on mud rheology. Plastic viscosity and 10 min gel strength have been noted as important markers or indicators that show when the blended fluid will give very good wellbore strengthening result. Absolute fracture sealing was noticed in two of the samples (sandstone and concrete) while running the re-opening pressure cycle which shows the excellent propping and sealing properties of the blend. A 25% increase in fracture pressure over the unblended mud was achieved in impermeable concrete core showing the applicability of the designed fluid in shale wellbore strengthening.
Future work involves field verification of the laboratory results achieved with the designed LCM blends.
Gupta, Vishwas P. (ExxonMobil Development Company) | Sanford, Shea R. (ExxonMobil Development Company) | Mathis, Randall S. (Exxon Neftegas Limited) | DiPippo, Erin K. (Exxon Neftegas Limited) | Egan, Michael J. (AIPC, Consultant to Exxon Neftegas Limited)
ExxonMobil, as operator for the Sakhalin-1 project, recently planned a drilling campaign at the Chayvo Field, Sakhalin Island, Russia. The focus of this campaign is the development of a thin oil column reservoir using extended reach drilling (ERD). This paper will provide an overview of the planning of these challenging wells at the edge of the ERD envelope, the associated technical and operational challenges, and the additional complexity of targeting a thin oil column in an ERD environment. Significant well design parameters, tools, and techniques to enable these challenging wells will be presented. Results to date from this drilling campaign will also be presented.
ERD has become a commonly used technique to economically access reserves from existing infrastructure and to reduce the facilities environmental footprint. The case history described in this paper illustrates the combination of planning, technical design, and operational practices required to push the ERD envelope further.
The distance of the reservoir from shore resulted in planned well lengths at the edge of the ERD envelope. Planning of these record wells involved building upon the Operator's previous experience as well as additional tools and methods to address the unique challenges. The technical challenges included uncertainties in the location of the oil column and fluid contacts, very accurate well placement for effective reservoir drainage and preventing early gas/water breakthrough, completing long horizontal intervals, and high torque and drag. The geologic uncertainties and wellbore positioning challenges were addressed using a combination of a single near horizontal pilot hole to locate both fluid contacts and a novel technique to minimize vertical position uncertainty using formation pressure measurements while drilling. Extensive torque and drag and wellbore stability modeling were performed to design the wells, operational parameters, and equipment. Completion designs were optimized to ensure successful placement in long horizontal intervals.
Effective removal of contaminants from drilling fluids is widely accepted as a key factor in achieving optimum drilling performance and reducing fluid cost. Current shaker technology reflects incremental advances in functionality related to size, vibration and screen technologies. This paper describes the development, qualification and field testing of an alternative solids control solution that provides advances on several aspects that conventional equipment is infested with. The findings presented are based on results obtained both during the qualification process and field testing. These processes have contributed to improved knowledge within solids control, drilling fluid treatment and waste stream handling. The alternative cost effective fluid management system described in this paper represents a step change within occupational hygiene; through the elimination of oil mist and vapour.
By using an innovative problem-solving approach several other technical solutions that addresses critical aspects related to the mud processing area (MPA) has also derived. These are all identified as critical to obtain an efficient drilling operation with lowest environmental impact. This intelligent fluid management system addresses multiple needs for both onshore and offshore drilling operations and facilitates:
• Remote monitoring and control of fluid management utilizing real-time data (e.g., density and viscosity control),
• Remote and real-time screen wear status and visual control of cuttings morphology
• Accurately monitors cuttings volumes to identify poor hole cleaning, rapidly identifying well kicks or lost circulation
• Removal of cuttings without screen blinding utilizing a conveyor filtration system
• Elimination of ancillary equipment like degasser, mud cleaner, desander and cuttings dryers
• Reduction in the need for heating, ventilation and air conditioning (HVAC) and elimination of the need for respiratory systems in the shaker room
• Minimisation of acid gas contamination through application of vacuum pressure; allowing safe removal of the gases
Kieschnick, Mike (Schlumberger) | Kieschnick, Michael L (Smith Bits, a Schlumberger Company) | Jacob, Tony (Schlumberger) | James, Biju (Schlumberger) | Karuppiah, Venkatesh (Smith Bits, a Schlumberger Company) | Hamilton, Rob (Smith Bits, a Schlumberger Company)
Drilling the 12¼-in tangent section (55-60°) through thick carbonate lithology in Qatar's offshore North Field is exceptionally challenging. In spite of bottom hole assembly (BHA) and parameter adjustments, the operator regularly experiences severe impact induced PDC cutter damage resulting in reduced bit life. Lithology (Hith to Khail) is predominantly interbedded carbonate/anhydrite, dolomite/argillaceous limestone with unconfined compressive strength (UCS) ranging between 9000-30,000psi. The operator wanted to improve rate of penetration (ROP) by stabi-lizing the bit body and reducing micro-balling tendencies. The objective would be to complete the 6000ft section in one bit run at a minimum ROP of 2000ft/24hr.
An FEA-based modeling system, rock strength identification program and computational fluid dynamics (CFD) analysis was used to investigate several 12¼-in PDC bit designs. The results of the simulations led to a new MSi716 design with back-up cutters strategically positioned on all blades to provide maximum durability in critical wear areas. After reviewing the results of the analysis, the operator requested additional bit design changes including a 6-in tapered gauge and managed depth-of-cut in the cone/nose areas to reduce reactive torque. A parameter sensitivity study was conducted to determine the optimal operating window (WOB/RPM) and to ensure the new PDC design would be compatible with a unique high-torque RSS which allows for higher weight on bit than standard rotary steerable systems to maximize rate of penetration potential.
The new design was run on the high-torque RSS/motor system and drilled 6,001ft of 12¼-in section at a high ROP of 139.4ft/hr setting a new North Field record. The average daily footage was 2572ft besting the old mark by 38%. Additionally, the run set a single 24hr footage record of 3100ft/day, 29% better than benchmark. Based on this outstanding bit performance the operator made these design changes a standard requirement for PDC bits in this application. The new design also helped standardize mechanical specific energy (MSE) values for future ROP gains.
Odegard, Sven Inge (eDrilling Solutions) | Risvik, Bjorn T. (Statoil ASA) | Bjorkevoll, Knut Steinar (SINTEF Petroleum Research) | Mehus, Oystein (Oiltec Solutions) | Rommetveit, Rolv (eDrilling Solutions) | Svendsen, Morten (eDrilling Solutions)
The paper presents a highly advanced training simulator that combines an advanced top-side simulator with a dynamic down-hole simulator with an advanced transient integrated hydraulics and thermal wellbore model and a dynamic torque and drag model. The simulator is aimed at drilling and well operations, and is able to handle most of the normal operations, including high pressure high temperature (HPHT) wells, through-tubing rotary drilling (TTRD), extended reach drilling (ERD) and managed pressure drilling (MPD).
The underlying simulator technology is modular, allowing for new modules to be added at a later stage. For instance, MPD control systems can easily be added to the simulator, allowing for training on an MPD operation with both the drilling crew and the MPD supplier. The simulator is able to use pre-programmed scenarios, replay, fast forward and rewind to facilitate efficient training and review sessions
Moreover, the simulator is designed to provide realistic personnel training on emergency procedures and operations such as well control in a safe environment, thereby limiting the human factor in critical operations as well as possibly improving the procedures by frequent use and revision. Also, the simulator allows for integration of HSE in early well planning through simulator training on the actual well to be drilled.
The main innovation is to use dynamic models verified in real-time operations together with an advanced top-side drilling equipment simulator for training on well specific scenarios.
The value added for the industry is to give the drilling and/or engineering teams a possibility to verify and train on identified risk elements prior to drilling a well, as well as retrain during the operation on a "true?? virtual copy of the well.
So far more than 60 drilling teams have experience from training, and the feedback has been very positive.
The paper will present the simulator as well as experiences from typical training cases on challenging wells.
With the ongoing changes affecting the global drilling industry, well integrity has become an area of great engineering focus and development. Cement bond analysis is of key interest as the consequences of failed, or partially complete, cementing
operations can, at best, be a costly delay in drilling operations and, at worst, an extremely hazardous safety issue. Traditionally, wireline acoustic tools have been used to analyze the quality of the cement bond between the casing and the formation. Wireline tools have been developed over many years to produce high-quality assessments of cement bond, which can then be confidently used to confirm well integrity. However, the conveyance method requires that the analysis be performed on the critical path and also that additional methods be used in high-angle wells. Logging-while-drilling (LWD) technology offers a potential alternative without these issues, provided the current limitations of the technology are understood and its applicability properly assessed as a fit-for-purpose solution. As a minimum, the LWD logging technique can provide a trigger as to whether more advanced logging techniques must be deployed or can be avoided.
This paper explores the applicability of LWD sonic tools to the analysis of cement behind casing. It considers both the currently accepted deliverable of top of cement (TOC) analysis, along with examples of more advanced processing techniques and their comparison to wireline cement evaluation, providing case study examples in each case. The benefits and limitations of these methods will be discussed, along with operational considerations to aid in successful logging, including the use of repeat logging passes to indicate changes in cement quality with time. The use of LWD sonic tools to identify casing collar connections on driller's depth, enabling the safe positioning of cased-hole whipstocks, is also covered, demonstrating a novel and little-used application of LWD technology.
High dogleg rotary steerable systems (RSS) were introduced for general industry use in 2011. These systems were developed for high dogleg shale applications in North American land operations. The initial systems were 6 ¾-in. These tools were designed to produce up to 15°/100 ft in 8 ½-in. to 8 ¾-in. hole size. High dogleg tools for different borehole sizes followed. The requirement for high dogleg RSS is now global, and the systems are being used to drill in areas where steerable motors previously dominated because of their higher dogleg capability. A new 4 ¾-in. RSS has been designed for high dogleg (15°deg/100 ft) and dogleg assurance applications. Additionally, a new high dogleg RSS for 5 7/8-in. to 6 ¾-in. hole sizes has been developed and field tested. The new slim-hole high dogleg RSS has proven to perform well and be a cost-effective solution in specific applications, such as difficult formations and multilateral well construction.
Ensco plc is an international drilling contractor which has experienced significant growth since its creation only 25 years ago to its current position as the second largest offshore drilling organization worldwide. It has recently doubled its size through the acquisition of another similarly sized drilling organization.
Despite this significant growth, and while being challenged by many issues from inside such as integration, and from the outside such as having to do business in a difficult market and in many different national cultures, it has achieved acknowledged excellent performance. Ensco plc was voted as the number one performer by major operators in an independent customer survey in 2010 and in 2011.
What processes and leadership has Ensco utilized to achieve this?
This paper will describe these processes and the leadership that has driven this success. They are not new; what Ensco has done is integrate existing and well known concepts in a way that has led to this success.
They involve an unshakeable belief in Ensco's Vision and Core Values, visible leadership that understands it and the organization has to continual change to adapt to an ever changing world. Its leadership also acts on making the Vision and Core Values come to life, a drive for consistent use of systems, and a belief and a preparedness to invest in the development of its people in competencies critical for its long term success.
These things underpin the creation of an organizational culture where people are more likely to accept the accountability and responsibility to do their personal best.
We will describe how the above was achieved and the steps followed to ensure sustainable performance. Key considerations in the strategy, whether consciously adopted or ortherwise by virture of the leadership programs exposed to Ensco's people included.
Reducing rig time and material costs for offshore wells is critical to a project's financial profitability. With the dramatic increase in the number of deepwater wells, new technologies and methods are needed to quickly and reliably complete wells. A case history of five deepwater large bore expandable liner hangers (ELHs) from late 2011 through the first half of 2012 in the Gulf of Mexico (GOM) show consistent material cost savings, reduced installation time, improved reliability, and increased versatility over conventional liner hanger systems. Four of these ELH systems were run off drill ships and one off a platform. A picture of the large bore ELH system is shown in Fig. 1.
The technological advances of ELH systems have increased well life and improved safety during liner installations over traditional systems. Sealing capabilities with expandable systems have evolved beyond conventional tools and the smooth radial flowpaths allow for greater ease of installation. A series of redundant sealing elements provide a gas tight liner top seal. Also, with the ELH system, rotation and reciprocation while cementing are possible.
This paper will describe offshore wells and the common problems associated with running intermediate liners. Expandable liner hanger technology will be explored to increase operator awareness of this beneficial technology. A comparison of ELH technology and the conventional systems in the same field are described within this paper.