bluuebunny/crossref_metadata_2025_split huggingface dataset:
Newtonian Fluid in Cementing Operations in Deepwater Wells: Friend or Foe?
Authors: Khalilova Polina , Koons Brian , Lawrence Don Woody , Elhancha Anouar 
Published: September 2013

Abstract
Cementation of wells, especially in deepwater has attracted a great deal of attention after recent loss of well control events and subsequent changes in regulatory requirements with respect to achieving effective zonal isolation, preventing the release of wellbore fluids to the environment and avoiding the need for cement job remediation[1, 2].
Deepwater well construction presents unique challenges for proper cementation. These challenges are driven by the greater complexity of deepwater (DW) wells. There is; narrower pore pressure (PP) and fracture gradient (FG) margin, use of oil based mud (OBM) or synthetic based mud (SBM) drilling fluid that is incompatible with water based cement slurries, additional length for the cementing fluids to travel due to the sea water depth increasing the risk of intermixing between fluids, technology pushed to the limit, and the cost of drilling in deepwater that is much higher than conventional wells.
Currently there are two main flow regimes used when planning for effective mud removal and cement placement: effective turbulent flow and effective laminar flow. Turbulent flow is generally considered the preferred method of efficiently removing fluids; however there are a number of requirements to be met in order for turbulent flow to be both safe and effective. Laminar flow is the most widely used due to the ease of placement design and the lower annular velocities required to achieve effective cement placement. Drilling fluids, weighted spacers and cement slurries can all be designed in effective laminar flow, since they exhibit a yield stress. Brines, water, and chemical washes are typically designed in effective turbulent flow.
In this paper the authors will discuss the factors to be taken into account when designing cement jobs using fluids in turbulent flow and some of the overlooked benefits of using turbulent flow design for mud removal. Case histories from DW wells cemented in the Gulf of Mexico region and risk factors will be discussed. It will be demonstrated that when designed and executed properly, the use of turbulent flow mud removal with Newtonian fluids can be beneficial in DW cementing operations.
A New Approach for Build Rate Estimation of Downhole Motors
Authors: Marchand Nicholas , Kalantari Masoud 
Published: September 2013

Abstract
Build rate prediction is a critical element in downhole drilling and proper BHA design. This paper presents a simple build rate prediction method that demonstrates improved accuracy for short bit-to-bend (SBTB) motors compared to the industry standard method.
The Three-Point Geometry method is the industry standard to calculate the predicted build rates of downhole motors. While this method provides reasonable results for conventional motor designs, it consistently fails to match with field data for SBTB motors. Field reports clearly demonstrate that SBTB motors can achieve significantly higher build rates than predicted by the three-point geometry calculations.
A new analytical method has been developed to predict the build rate of conventional and SBTB motors. The new method assumes that as the bit advances, it will drill in the direction it is pointing so that the resulting curved path is tangent to the inclination of the bit. Based on this bit-tangency assumption and a defined upper contact point, the predicted hole curvature can be calculated for a given motor configuration.
Results from the Bit-Tangency method provide a more accurate indication of the increased build rates that SBTB motors can achieve. Further, the results of the new method for conventional motors conform to field data and the three-point geometry results. Hence, the Bit-Tangency method can replace the standard Three-Point Geometry method of build rate prediction for both conventional and SBTB motors.
Multiple Well Deconvolution
Authors: Cumming J. A. , Wooff D. A. , Whittle T. , Gringarten A. C. 
Published: September 2013

Abstract
In well test analysis, deconvolution is used to transform variable-rate pressure data into a single constant-rate drawdown suitable for interpretation. It is becoming part of a standard work flow for exploration and appraisal well test analyses and in production test analysis where there are no interference effects from nearby wells.
This paper develops and extends the single-well deconvolution algorithm of von Schroeter (2004) to the larger and more complex multiwell deconvolution problem.
To validate the algorithm, it is applied to a synthetic example with known solution and an uncertainty analysis is performed to quantify the impact of non-uniqueness on multiwell deconvolution.
The use of the algorithm is further illustrated with a field example.
Fully Rotating PDC Cutter Gaining Momentum: Conquering Frictional Heat in Hard/Abrasive Formations Improves Drilling Efficiency
Authors: Zhang Youhe , Burhan Yuri , Chen Chen , Tammineni Sandeep , Durairajan Bala , Mathanagopalan Siva , Ford Robert 
Published: September 2013

Abstract
A fixed PDC cutting element creates an inherent limitation because only a small portion of the diamond table contacts formation and as the cutter wears/chips, drilling efficiency declines. It is well documented that wear flats generate a high degree of frictional heat which breaks down the diamond bond and in extreme cases can even convert synthetic diamond back to graphite.
To solve the issue a research initiative was launched to investigate different methods to enable a PDC shearing element to fully rotate while drilling to increase overall cutting efficiency and bit life. Engineers investigated different retention methods and cutting structure designs to create the optimal driving force to accomplish the objective. Several designs were implemented that hold the cutter securely in place and allow full cutter rotation. These assemblies were modeled using an FEA-based system and then tested in the laboratory to evaluate function and strength. Experiments confirmed the new rolling cutter (RC) was able to shear an extended section of rock with a consistent force level (lbs). Conversely, the traditional fixed-cutter assembly required steadily increased force to drive the cutter the same distance. Examination of the rolling cutter's dull condition clearly indicated significantly improved durability and cutting efficiency.
The recent introduction of a new rolling cutter PDC bit that utilizes the entire 360° of diamond edge has delivered positive results in field trials. Initial testing was targeted at the highly abrasive Granite Wash formation in Western Oklahoma/Texas Panhandle where cutter wear is the predominant failure mechanism. Application challenges include low ROP and premature tripping for a new bit. A six-bladed prototype PDC bit was manufactured with rolling cutters strategically positioned in the shoulder area. The bit was run on a steerable motor through the horizontal interval with good results increasing total footage and ROP capabilities.
In the central USA the rolling cutter has been run more than 70 times and has increased average footage totals by 56% compared to 450 offsets drilled with conventional fixed cutter PDC bits from various manufacturers. The authors will present results of field tests and two case studies that document performance improvement in these challenging drilling environments. They will also outline plans for future development.
Case History: Recent Lower Tertiary Multi-Zone Single Trip Deepwater Completion
Authors: Joseph Kevin P. , Ogier K. Scott , Moore Ronnie 
Published: September 2013

Abstract
Multi-Zone Single Trip (MST) technology is used to perform sand-control treatments individually to multiple zones in a single trip. In Deepwater installations, Well Integrity, Operational Efficiency and Completion Excellence are critical success factors for overall project returns. Well integrity is accomplished by ensuring that completion components conform to the extreme downhole well conditions; that well control is present during each stage of the completion operations; and that zones are positively isolated during the high pressure frac-pack treatments. Also, well integrity needs to be maintained during the selective isolation string deployment and throughout the production life of the well. Operational efficiency is accomplished by establishing clear guidelines during the planning phase of the wells; ensuring the right personnel are involved at the right time; identifying and eliminating any possible operational risk; simplifying tool manipulations; establishing downhole tool diagnostics that enhance decision making; and finally, improving downhole tool visualization for operational clarity. Completion excellence is achieved by ensuring completion components are fit-for-purpose for the extreme high pressure and erosive environment with maximum flow areas for optimum production, built-in redundancy for flawless executions, and software modeling to simulate downhole conditions from installation through production phases. This paper is meant to show how these features were used in the most recent completion in the Cascade field and provide recommendations for similar operations while identifying areas of improvement for upcoming installations.
Comparison of the Impact of Fracturing Fluid Compositional pH on Fracture Wall Properties in Different Shale Formation Samples
Authors: LaFollette Randy F. , Carman Paul S. 
Published: September 2013

Abstract
Fracturing fluid compositions have historically been formulated to achieve desired rheological properties under the conditions of pump time and temperature in the subsurface. However, fluid selection best practices came into being when conventional and mixed conventional and tight-gas sandstone reservoirs dominated oil and gas operations. Those reservoirs consisted mainly of quartzose sandstones cemented by quartz overgrowths or calcite. Those rocks were relatively unreactive to water-based fracturing fluids, except for their grain-coating clay minerals. Only rarely was clay present in the reservoir rock-pore network in sufficient quantity to contribute to changes in fracture wall mechanical properties such as Brinell hardness. The changeover in the North America hydraulic fracturing market to include the shale plays has brought into question whether rheology at time and temperature should remain the dominant fluid design criteria.
Samples of Bakken, Huron, Haynesville, and Marcellus shale core material have been tested against different fracturing fluid compositional pH values for time periods up to 8 months. The shale samples were subjected to Brinell hardness measurement before and after testing with pre-test measurements being taken in the wet condition and post-test measurements being done in the dry condition. Water composition was measured before and after each test, as was proppant strength.
Results indicate that pre-and post-immersion Brinell hardness values vary from one shale sample to another. Samples having different mineral composition may have different softening response to wetting. Also, natural and man-made proppants exhibit different degrees of strength loss or retention under long-term test conditions.
This paper is significant in that it directly compares measurements related to proppant embedment potential across different shales. It also provides a series of data points to aid in choosing particular fracturing base fluid compositional pH values for treatment design in wildcat areas.
Critical Evaluation and Improvement of Methods for Determination of Matrix Permeability of Shale
Authors: Civan Faruk , Devegowda Deepak , Sigal Richard 
Published: September 2013

Abstract
Previously available interpretation methods developed for determination of gas permeability from crushed samples are mostly applicable for conventional porous rocks of reasonably high permeability. This paper presents an improved formulation which honors the relevant physics of fluid, transport, and shale-rock conditions for determination of extremely-low nanodarcy gas permeability of shale by pressure-pulse transmission testing of crushed shale-rock particles. The new method is demonstrated by means of typical simulated test conditions. Assuming viscous, Darcy flow instead of the nonDarcy flow yields almost twice the actual value of the intrinsic permeability for this case.
A New Finite-Element Numerical Model for Analyzing Transient Pressure Response of Naturally-Fractured Reservoirs
Authors: Doonechaly Nima Gholizadeh , Rahman Sheik , Cinar Yildiray 
Published: September 2013

Abstract
This paper presents a new numerical model for analyzing transient pressure test data taken from naturally-fractured reservoirs. The model computes well pressures for a single well completed in a naturally-fractured reservoir. It models characteristic properties of naturally-fractured reservoirs including fracture orientation, fracture length, fracture density and fracture distribution. A single-phase, slightly compressible fluid flow is assumed. Fluid flow is modelled based on a hybrid approach which combines single continuum (block-based permeability tensor for small to medium fractures) and flow in discrete fractures (long fractures). A sensitivity analysis is presented to examine the effects of fracture density, fractal dimension and percolation probability. Then the model is validated against two worked examples reported in the literature. Results reveal that new model can predict transient pressure response of complex naturally-fractured reservoirs. Hence, it can be used to match pressure test data and diagnose characteristic properties of naturally-fractured reservoirs.
A Comprehensive Kinetics Model for Light Oil Oxidation/Combustion Reactions under High Pressure Air Injection Process (HPAI)
Authors: Barzin Y. , Moore R. G. , Mehta S. A. , Ursenbach M. G. , Tabasinejad F. 
Published: September 2013

Abstract
It is acknowledged that chemical reactions and their kinetics play a major role on the success of both light and heavy oil air injection processes. Historically, Light oil reactions have been characterized mostly using conventional heavy oil kinetics models. However, sensitivity of the reaction kinetics to phase behavior and compositional changes in light oils call for a comprehensive study of kinetics of light oil oxidation. This paper provides a new and comprehensive kinetic model for light oils oxidation/combustion reactions under HPAI, through experimental studies and numerical simulation.
For the purpose of this research, a high pressure ramped temperature oxidation reactor (HPRTO) was designed. 15 air injection and nitrogen injection experiments were conducted on the mixture of light oil, water, and core. Based on the data, observations, and understandings achieved during the course of the experimental study, a reaction kinetic model was set up. This primary kinetic model was then incorporated into a thermal numerical simulation model to replicate the behavior of the conducted air injection tests. After fine-tuning of some kinetic parameters against the experimental data, the final proposed model was verified by its successful application to two other different cases.
The significant finding of this research, which is the main feature of the proposed kinetic model, was the recognition and characterization of the potential vapor phase combustion reactions during the HPAI process and incorporating them into a light oil kinetics model. The model integrates the hydrocarbon compositional changes and energy generation characteristics of the oxygen addition or so called LTO reactions. Introducing the concept of flammability range into the kinetic model and defining the flammable limits for vapor fuel mixture in this model enables accurate prediction of ignition and exhaustion of the combustion reactions in the vapor phase.
Lack of a reliable kinetics model for incorporation into field numerical simulations has been a limiting factor to the prospective vast applications of HPAI as an enhanced recovery method. The kinetics model proposed in this paper, which is supported by extensive experimental data, could successfully predict the oxidation/combustion behavior of two different light oils under the conditions associated with high-pressure air injection tests. The paper also presents a framework for application of the kinetics model to any light oil under HPAI.
Real-Time LWD Sonic Semblance Image and the Step Change in LWD Sonic Applications—A Case Study from Latin America (Mexico)
Authors: Mickael Medhat , Barnett Craig , Maranuk Chris , Nye Rebecca , Diab Mohamed , Carreira Javier Armando , Morales Victor Arreola , Batista Erika Nino , Chi Jose Edilberto 
Published: September 2013

Abstract
The need for reliable logging-while-drilling (LWD) sonic data in real-time has been of great interest to many operators since inception. However, providing such information reliably requires many challenging tasks. Unlike wireline tools, where waveforms are sent and processed on the surface in real-time, the waveforms of an LWD sonic tool cannot be sent in real-time due to bandwidth limitations. This requires the data to be processed downhole and only the processed data to be sent in real-time. Traditionally, windows were used to define the range of the real-time compressional velocity. However, a major drawback to this approach is the requirement of knowing the compressional arrival range beforehand and the possibility of receiving a different arrival. For example, fast shear could be confused with slow compressional data. Sending a complete semblance image in real-time is the best way of capturing all arrivals. However, data must be inelegantly compressed to maintain the arrival times yet reduce the bandwidth to a minimum. A new sonic LWD tool has been developed to provide high-quality real-time sonic semblance images, creating opportunities for obtaining this information while drilling. An offshore case study comparing the real-time sonic images to the recorded memory data in terms of resolution and data quality will be investigated. The paper will discuss the uses and applications of the sonic semblance image and its real-time value. This proven data acquisition process is crucial in allowing the end user to access all the formation evaluation data, thus improving real-time decision making.
Technological advances in LWD services have had a direct impact on the ability to evaluate a reservoir and provide production planning on a foot-by-foot basis. The amount of downhole data processing and data compression required plays a critical role in delivering real-time sonic data while drilling. High-resolution, real-time semblance images can be obtained in real-time, and are expanding the uses and applications over traditional delta-t data acquisition.
Operating companies have formed an outdated opinion that real-time LWD sonic data is unreliable and requires post-processing. With newer technology, high quality semblance images can be provided in real-time and, as a result, there is a shift in the way operating companies use the data for analysis and planning. The offshore environment has always presented a difficult challenge for acoustic tools in general; however, with the scientific advances in LWD tools, continuous compressional and shear arrival from the real-time semblance images can prove useful. This case study will also provide basic background information on the lithology in the region, highlighting why sonic data in particular was required in real-time.
The Growth of Coiled Tubing and the Benefits of Thinking Small Again
Authors: Terry Adrian , Pate Brad , Stanley Rick 
Published: September 2013

Abstract

Description
The development of coiled tubing as we know it today dates back to the early 1960s. It has become an integral component of many well service, workover applications and programs. While well services and workover applications still account for approximately 75% of Coiled Tubing (CT) use, technical advancements have increased the utilization of CT in both drilling and completion applications1.
In recent years the industry has been trending towards drilling deeper, highly deviated and horizontal wells. In turn this has also included larger and more complex completions. This trend has challenged the CT service providers to develop larger, more robust and innovative equipment to deploy larger CT sizes and to support increasingly difficult wellbore interventions. It is important that we understand the history behind the initial small CT units (CTUs) and pipe sizes, their limitations and the evolution to the large CTU sizes used today.
This paper describes why the industry still requires smaller, lighter CTUs and associated pipe sizes along with the benefits they offer today, particularly in offshore applications.
Interpretation of Array Production Logging Measurements in Horizontal Wells for Flow Profile
Authors: Liao L. , Zhu D. , Yoshida N. , Hill A. D. , Jin Minquan 
Published: September 2013

Abstract
Interpretation of production logging in multi-phase flow wells is challenging, especially for highly deviated wells or horizontal wells. Flow regime-dependent flow conditions strongly affect the measurements of production logging tools. Segregation and possible back flow of denser phases result in misinterpretation of the inflow distribution. To assess the downhole flow conditions more accurately, logging tools have been developed to overcome the flow regime related issues. Multiple-sensor array tools measure the fluid properties at multiple locations around the cross-sectional area of the wellbore, providing a distributed measurement array that helps to relate the measurements to flow regime and translate the measurement to inflow distribution. This paper present a methodology for using array data from production logging tools to interpret downhole flow conditions. The study uses an example logging tool that consists of 12 resistivity, 12 capacitance probes, and six spinners around the wellbore circumference. The method allows interpretation of phase volumetric flow rates in sub-divided cross-sectional areas based on sensor locations. The sub-divided area method divides the wellbore cross-sectional area into several layers depending on the number and arrangement of the sensors with each layer containing at least one sensor. Holdup and velocity outputs from sensors in each wellbore area segment are combined to calculate the volumetric flow rates of each phase in each segment. These results yield a profile of flow of each phase from the high side to the low side of the wellbore, and the overall flow rates of each phase at every location along the well where the interpretation method is applied.
The method developed was used to interpret the flow profile of an Eagle Ford well producing gas and water at downhole conditions. A reasonable profile of gas inflow was obtained and the profile was similar to that interpreted with a commercial production log interpretation software package. The interpretation of the water flow profile was complicated by low total water production rate and variations in wellbore inclination.