bluuebunny/crossref_metadata_2025_split huggingface dataset:
Milling Low-Side Casing Exit Windows In Horizontal Wells: A Case Study
Authors: Hogg Cliff , Barker Ron , Valverde Penangos Juan Carlos , Caceres Leon Rodrigo , Gandara Carlos Alberto , Ortiz Prada Everardo , Gil Chipatecua Paola Adriana , Rueda Henry 
Published: June 2014

Abstract
In order to access additional reservoir, Hocol S.A. recently sidetracked out of a well located in the Ocelote Field, Colombia. The optimum path for the new well trajectory required exiting from the low side of the cased mainbore in a horizontal section of the existing well. Additionally, the proposed drilling assembly would utilize a Rotary Steerable System (RSS) in order to best reach target reservoir. Both of these requirements created additional challenges to the operator when designing a reliable casing exit operation.
The RSS, which requires rotation along the length of the drill pipe, created concern due to the sidewall loading forces at the junction point which could have potentially impeded both downhole bit performance and drill pipe life. Meanwhile the desire for a low side casing exit in a horizontal wellbore generated concern that gravity would enable the whipstock to sag towards the low side of the casing and potentially interfere with drilling assembly trips through the window and into the lateral open hole. The operator sought out solutions that addressed both of the issues while still providing field proven casing exit techniques. The technology ultimately selected by the operator involved a casing exit system with a longer whipstock face therefore providing a longer casing exit window and reduced dog leg severity through the junction area. Additionally, the chosen whipstock system provided a patented "fulcrum design" to actively lock the whipstock assembly against the casing wall and away from the low side casing window in horizontal installations.
This paper provides background information on the Ocelote Field and the drivers behind this sidetracking project. The design and operational challenges created by the desired drilling program are discussed along with a further description of the specific design problems encountered including the chosen installation equipment and techniques that addressed these challenges. Finally, the actual installation process along with problems encountered and successes achieved is covered.
Modeling for MPD Operations With Experimental Validation
Authors: Landet Ingar Skyberg , Mahdianfar Hessam , Ulf Jakob F. Aarsnes , Pavlov Alexey , Aamo Ole Morten 
Published: June 2014

Abstract
Heave motion of floating rigs complicates the control of pressure in MPD. During connections, the drill string is detached from the draw-works and moves with the heaving rig, causing downhole pressure fluctuations. As a step towards designing control schemes to actively attenuate the fluctuations, a fit-for-purpose mathematical model of well hydraulics is derived based on a finite volumes discretization. The model incorporates various MPD operations, including circulating in new mud, vertical motion and rotation of the drill string. Using field data from UllRigg - a full-scale experimental drilling facility - the model is validated with respect to the different MPD operations. Since an automatic control scheme in principle inherits the complexity of the model on which it is based, it is of great importance to develop models of minimal complexity. It is shown by simulations that significantly reduced order models obtained by applying the method of frequency-weighted balanced model reduction to large models outperform those obtained by simply reducing the number of control volumes. This result is particularly important for the dynamics involved during heave, since a significant number of control volumes are required to model this case. The contributions of this paper enable development of control systems for automated MPD operations from floaters.
Investigation of Sand Production Onset: A New Approach Based on Petrophysical Logs
Authors: Alipour Tabrizy Vahid , Mirzaahmadian Yaser 
Published: June 2014

Abstract
This paper pertains to prediction of elastic rock parameters and sanding problem onset based on petrophysical logs as a novel in-situ method. The paper addresses two main parts. In the first part, petrophysical evaluation of well log data is coupled to the Mohr-Coulomb failure criterion to predict the critical well bore pressure. Mathematical modeling is performed to demonstrate the application of well logs for prediction of sanding problem onset. In the second part, two sets of well log data from fields A and B in the Barents Sea (Norway) are used to show the applicability of the method. It has been shown that the critical well bore pressure for the Tubåen formation in field A is negative indicting the low possibility of sand production while in the field B, the critical well bore pressure is positive for the same formation. The sanding problem in field B has been observed during production and confirms the validity of the method. The different behavior of the two case studies can be linked to the packing of sand grains and cementation due to the burial depth and considerable overburden pressure. The presence of hydrocarbon and water in field B results to the diversity of sonic travel times and the rock elastic parameters compared to the corresponding data of the field A where the formation fluid is only water.
Long-Term Proppant Performance
Authors: Raysoni N. , Weaver J. 
Published: June 2014

Abstract
The hydrothermal degradation of alumina-based proppants, which can lead to significant loss of fracture conductivity, has been the topic of recent papers. Most of these studies were necessarily compromised by being performed on either too short of a time scale to produce geochemical effects or by using unrealistic temperature conditions to accelerate the geochemical reactions. Those studies, however, provided insight that geochemical reactions likely occur during production from hydraulically generated fractures and gave evidence of possible long-term proppant instability.
This paper presents proppant-pack permeability and proppant crush-strength data collected from a selection of hydrothermal tests performed in sealed test cells packed with proppant and formation material with no flow and no mechanical closure stress. Long-term proppant performance was determined by evaluating the proppant after 0, 25, 45, 60, 90, and 180 days of hydrothermal exposure at 300 and 450°F, resulting in verification that proppants continuously degrade with time at all temperatures. A typical long-term proppant-testing result was 80% loss in proppant-pack permeability and 40% loss in proppant crush strength with just 180 days exposure at 300°F at typical reservoir pH. These tests were performed both with and without formation material present to demonstrate the impact of reservoir/proppant compatibility. Scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX) analyses verified that dynamic molecular rearrangement occurs over the entire temperature range; albeit, at an accelerated rate as temperature increased. Extensive effort to quantify both the accuracy and repeatability of testing procedures used in this study were made and will be presented. This involves measurement of pack permeability using water before and after hydrothermal exposure, and single- proppant-grain crush-strength determination using Weibull statistical analyses.
This paper presents substantial data to support the importance of proppant compatibility when selecting the best proppant for long-term fracture conductivity. And it suggests that methods in addition to API crush and conductivity procedures need to be developed and implemented to properly rank proppant performance.
Collaborating on Real-Time Geomechanics across Organizational Boundaries
Authors: Magini L. , Molteni D. , Zausa F. , Fardin N. , Pausin W. 
Published: June 2014

Abstract
Real-time geomechanics techniques contribute to managing the risks and challenges faced during the realization of a well, providing, in particular, decision-making support to drillers for managing the safe mud-weight window and wellbore instability and for bridging knowledge of the rocks’ mechanical properties to drilling practices. Wellbore instability is often not caused by geomechanical conditions alone and is, in many cases, caused by the combination of geomechanics and the drilling process.
This paper describes the application of real-time geomechanics to a remote exploration project located in a challenging field and how operations benefited from this technique. A previously drilled well in the field presented serious wellbore instability issues during tripping. The instability was suspected to have caused problems during the wireline logging phases, which made it impossible to complete the formation evaluation program. The stakeholders were based in four different locations: the rig site, the operator’s office, the operator’s real-time center and the service company’s real-time center. Interaction among stakeholders was coordinated through the operator and service company real-time centers. The use of available infrastructure and remote collaboration software created a collaborative environment that successfully supported the operator’s decision-making process, with the following specific achievements: well total depth selection based on maximum allowable equivalent circulation density before incurring in losses; avoidance of wellbore instability events during drilling, tripping or logging phases; and first operator to achieve successful wireline fluid sampling in the deeper formation of this field.
Integrated Drilling, Completion, and Stimulation Approach Facilitates High-Productivity Horizontal Well with 10,000-ft Pay Interval
Authors: Jorden John , Jackson Alfred , Al Marzouqi Mohamed Abdulla , Keller Stu , Shuchart Chris , Ivan Catalin , Phi Mike 
Published: June 2014

Abstract
A maximum reservoir contact (MRC) well with a 10,000-ft horizontal completion interval and a 20,000-ft measured depth was recently drilled and completed in a major carbonate oil field offshore Abu Dhabi. This paper will describe the integrated drilling, completion, and stimulation approach taken for planning and executing this well. The well is completed with 38 inflow control device (ICD) subs containing 55 ICD nozzles along with 16 swellable packers. The placement of the packers and ICDs was based on reservoir inflow modeling and advanced acid modeling to ensure that adequate stimulation could be achieved through the ICDs. A specially-formulated drill-in fluid containing a pH-activated filter-cake breaker was used to minimize formation damage. To fine tune the ICD settings and locations, reservoir pressures were measured along the open hole using a formation-pressure-while-drilling tool. The 10,000-ft, 6-5/8-inch completion liner was run to TD without difficulty. A tapered drill string was run inside the liner and stabbed into a pre-installed permanent packer located in the shoe joint of the liner. The breaker system was activated by circulating a weak acid through the drill string inside the liner. To facilitate future stimulation through the ICDs, a plug was pumped through the drill string and landed in a profile located in a short tail pipe attached to the permanent packer. The well has been put on production and is one of the best producers in the field. Production logging tool (PLT) data indicate that the entire 10,000-ft completion interval is contributing. Although further analysis is ongoing, the preliminary evidence suggests that little or no formation damage was caused by the drilling and completion process. This paper points out the importance of an integrated drilling, completion, and stimulation approach for planning and executing MRC wells in carbonate reservoirs.
Understanding How the Placement of an Asymmetric Vibration Damping Tool Within Drilling While Underreaming Assemblies Can Influence Performance and Reliability
Authors: Kabbara Alan , McCarthy John , Burnett Timm , Forster Ian 
Published: June 2014

Abstract
This paper describes the work, on test rigs and full-scale drilling rigs, carried out with respect to placement of an Asymmetric Vibration Damping Tool (AVDT) within drilling while underreaming operations.
An AVDT, by virtue of the forward synchronous motion imposed on the drill string, offers benefits in minimizing down hole vibration related tool failures and therefore maximizing ROP. Of interest in using the AVDT is the tendency to minimize stick slip by means of the parasitic torque it generates. This is of particular importance during underreaming operations.
While underreaming, stick slip can result in low ROP and potentially an increased incidence of down hole tool failures. The use of an AVDT in these operations has been shown to significantly reduce stick slip.
However, due to the forward synchronous motion caused by the AVDT, there is the potential to cause eccentric wear to BHA components in the vicinity of the AVDT. If allowed to progress, this eccentric wear can cause a reduction in down hole tool life and drilling performance. Eliminating eccentric wear would be beneficial in reducing repair costs, extending component life and further improving drilling performance.
To minimize eccentric wear and maximize drilling performance, the placement of the AVDT within the bottom hole assembly is critical. This paper describes how the placement of intermediate stabilizers between the AVDT and the underreamer can minimize eccentric wear to the underreamer and the adjacent drill string due to the forward synchronous whirl induced by the AVDT.
This approach allows the full benefits of the AVDT to be recognized while reducing the potentially damaging effects of eccentric wear to other BHA components. The work has drawn upon small scale rig testing, full scale testing at the Ullrigg test facility in Norway and from real-world drilling and underreaming operations in the USA.
Efficient and Reliable Vertical Drilling of Top Holes with RSS in Deepwater GOM
Authors: Chamat Elias , Israel Riaz 
Published: June 2014

Abstract
The requirement for a reliable technology to efficiently drill vertical large tophole sections has increased substantially along with the number of deepwater wells. Inefficient salt drilling with mud motors and high rig spread rates were some good reasons for operators to prefer rotary steerable tools (RSS) in large-hole sections since they became available to the Gulf of Mexico (GOM) in October 2004. As the use of RSS in 26-in. and 24-in. sections is becoming more popular and deeper wells require minimum dogleg severities in top holes, the use and requirements for RSS have taken higher importance.
Deepwater wells are drilled through ultrasoft formations in the first 800 ft; additionally, surface conductors are normally set with an inclination at the shoe of 0.5° to 2°. The unconsolidated sediments and inclination at the beginning of the 26-in. section present a challenge to either hold vertical or drill directionally with mud motors and RSS. The combination of the issues resulted in difficulty to verticalize a few wells below the surface conductor.
While from 2004 to 2009 84% of the runs were successful, a major study was conducted during the drilling moratorium in the GOM to understand the environmental conditions that were the root cause of the issues described above. The investigation of 58 bit runs with 26-in. RSS performed from 2004 to 2010 in deep water were studied using advanced drilling software to understand and solve the issue of inability to drop inclination and, in a few cases, of unwanted inclination buildup. The advanced drilling software included time- and-depth based replay of the drilling operation, bottomhole assembly (BHA) tendency, BHA vibration models, unconfined compressive strength (UCS), and e-Caliper computations.
The study helped in understanding that conductor inclination and instantaneous borehole washout, in the first 800 ft below mudline (BML) due to UCS values as low as 350 psi, hinders the RSS push-the-bit pads from contacting the borehole, preventing a drop in inclination and, in some cases, allowing further inclination buildup. As this study was concluded during the moratorium shutdown, the lessons learned and best practices gathered helped to optimize BHAs, drilling parameters, and drilling practices. Implementation of these allowed all 26-in. RSS runs made post-moratorium to deliver vertical well intervals.
Data Aggregation and Drilling Automation: Connecting the Interoperability Bridge between Acquisition, Monitoring, Evaluation, and Control
Authors: Sadlier Andreas , Laing Moray , Shields John 
Published: June 2014

Abstract
Although the oil and gas industry continues to progress with drilling automation, technical challenges remain and must be addressed before this vision can become a reality. One of these challenges is the data aggregation between operators, service companies, drilling contractors and equipment manufacturers. Automation requires that the system not only control sub processes, it must also enable more complex intelligent systems to plan and react to real-time evaluation criteria and respond to predictive intelligence in real time. Data from control systems such as top drives, and evaluation systems such as downhole logging while drilling (LWD) sensors, must be aggregated in a meaningful way so it is portable, contextual, and actionable. Consider controlling the rate of penetration (ROP) based on predictive analytics assessed from formation evaluation (FE) data provided by an LWD sensor. To achieve this, intelligent control and evaluation systems must monitor and exchange information and events within a single, shared perspective.
In this paper, we review several technologies currently in use throughout the drilling industry— WITS, WITSML, OPC and PROFIBUS—and present case studies describing the current roles these technologies play and the problems they solve. The authors then analyze the limitations between these interoperable systems and associated barriers in achieving the drilling automation vision.
This paper recommends defined goals for the data aggregator and identifies existing challenges surrounding its deployment in current drilling automation environments. The authors also provide recommendations for how the industry should proceed with the implementation of data aggregation for automation. These recommendations ensure drilling automation becomes more than simple process mechanization, but advances towards intelligent systems that transform plans into reality and optimize performance and cost.
A New SBM for Narrow Margin Extended Reach Drilling
Authors: Lee John , Cullum Daryl , Friedheim Jim , Young Steve 
Published: June 2014

Abstract
Extended Reach Drilling (ERD) wells drilled nowadays can reach a step-out of 10 km (33,000 ft) and thus present many drilling challenges, including torque and drag, hole cleaning, wellbore stability, equivalent circulating density (ECD) management, lost circulation management, just to name a few. These challenges can severely limit the desired well depth or increase the operation time, particularly in deepwater environment. A new synthetic-based flat rheology drilling fluid (SBM) with new emulsifier and rheology modifier package has been designed for narrow margin ERD wells.
This newly developed flat-rheology SBM utilizes a novel, single emulsifier to simplify fluid formulation, improve emulsion stability, enhance thermal stability, and provide surface wetting and fluid lubricity. This allows the system to be formulated for any ERD applications with mud weights up to 18.0 lb/gal and temperatures up to 350°F. In addition, the system uses a new rheology modifier that provides temperature-independent rheology profile for better hole cleaning, barite suspension, ECD management and lost circulation control.
A recent field trial conducted in deepwater GoM indicated that the new system is easy to handle and provides good fluid performance in terms of drilling rate, ECD management, lost circulation control and hole cleaning. The SBM at one time was severely contaminated due to salt water flow but the fluid held together without any problems. Similar results on drilling performance were observed with another onshore field trial that used a non-synthetic-based fluid.
This article describes the new flat-rheology SBM system with examples showing typical mud formulations, fluid properties, barite sag performance data, field test data and computer hydraulics simulation of ECD impacts.
First Successful Rigless Acid Tunneling Job in Mauddud Carbonate Reservoir in Raudhatain Field, North Kuwait
Authors: Ashkanani F. , Sharma S. S. , Al-Ajmi M. , El-Daoushy A. , Saleh I. 
Published: June 2014

Abstract
RAMA-Pilot1 is a Mauddud open-hole well which is located in Raudhatain field-North Kuwait. The well had a barefoot completion and it was producing on ESP. Due to low rock quality, the well was performing less than expected levels.It was selected as an acid tunneling pilot for this project to create tunnels and new pathways inside the open-hole section. This is to increase reservoir contact, improve well productivity & eventually increase the near wellbore deliverability.
Two tunnels were created successfully inside the open-hole section and the results indicated that the productivity index increased by 3 times from 1.3 to 3.87 bpd/Psi.
This successful job was also possible from the lessons learnt, from an earlier attempt of acid tunneling in an Effluent Water Disposal (EWD) well. The job was not successful, and subsequent failure analysis of the job showed an "undersize tool in an oversize hole". So this time sufficient care was taken to measure the hole size properly to size off the acid tunnel tool accordingly.
RAMA-Pilot1 success had not only lead to restore & increase wellproduction, but it would also pave the way to enhance oil production and opening up possibilities for field wide applications especially in low PI carbonate reservoir wells. Also, it is considered for improving EWD wells performance by this technique.
RAMA-Pilot1 is the first "dendritic" well with extensive wormholes created by acid tunneling for maximum reservoir contact. The whole effect is aptly demonstrated by the change in PI of thewell before and after the acid tunneling as mentioned before.
This technique can be planned for any type of wells (EWD, oilwell, water injector) provided there is an open hole and tunnel that is created will be stable.
Econimically, acid tunneling technique compares favorably with alternative stimulation options in both time and money savings.