bluuebunny/crossref_metadata_2025_split huggingface dataset:
Challenging Complex Deltaic Reservoirs on the Orinoco Heavy-Oil Belt Aided by New-Generation Azimuthal Deep-Resistivity Tools and Advanced Real-Time Geosteering Techniques: Successful Case Study from the Eastern Venezuela Basin
Authors: Bejarano Celia , Castillo Elsy , Germain Pierre , Mendoza Hector , Manrique Carlos , Chacin Luis , Pineda Giser , Mendez Osbadis 
Published: December 2010

Abstract
A campaign to successfully drill and geosteer fourteen horizontal wells was performed in the Orinoco heavy-oil belt of eastern Venezuela. This campaign used the latest logging-while-drilling (LWD) azimuthal deep-resistivity tools in conjunction with specialized modeling and wellbore positioning techniques for a full geosteering service. Two simultaneous clusters (YA and SD), located in the southern part of the field, were the subject of this complete solution. The application of a full, real-time geosteering technique that combined the real-time responses of the tool and a model, measure, and optimize workflow enabled the flawless wellbore placement within a reservoir with a challenging stratigraphy and complex sedimentological environment and having notorious operational difficulties.
All of the wells were drilled in a deltaic depositional environment with average sand thickness ranging from 10 to 15 ft. Lateral facies changes, heterolitic beds, thickness variations, and pinch-outs were observed in this environment. The use of azimuthal tools made it possible to define the origin (relative to the wellbore) of these stratigraphical variations, which decreased the while-drilling uncertainty in the decision-making process. From a drilling perspective, extremely high rates of penetration (ROPs) of up to 1,000 ft/hr were achieved, which is common for these largely unconsolidated, highly permeable, heavy-oil sands. These fast operations required an efficient and reliable geosteering solution that enabled swift reaction to maintain the well path within the reservoir boundaries. Our solution proved to be very valuable, as we helped in reducing frequent sidetracking performed when drilling these deltaic units, thus minimizing NPT.
The outcome, including optimized well placement, reduced uncertainties in decision making, and improved rig-time effectiveness, were possible by operating with an integrated approach. Under this approach, geoscientists and drilling engineers from the operating company and the service company shared information on a real-time basis and worked as a multi-disciplinary team to make the best wellbore trajectory decisions.
Wellbore Strengthening – Where Field Application Meets Theory
Authors: Barrett S. , Cassanelli J. P. , Manescu G. , Vasquez G. , Growcock F. 
Published: December 2010

Abstract
In recent years there has been a growing awareness of the importance of Wellbore Strengthening Material (WSM) for sealing drilling-induced and natural fractures both in permeable and impermeable zones. This paper details the application of a software tool designed specifically for determining the optimum blend of WSM to drill the formations of the challenging Cashiriari field in Peru.
Several theories have been proposed to explain techniques which are in vogue for mechanically strengthening wellbores so as to control fracture propagation: Hoop Stress Enhancement ("Stress Cage") theory involves increasing the near-wellbore stress, which is usually carried out by opening fractures to tighten the wellbore and sealing the fractures immediately in that open state; "Fracture Closure Stress" theory utilizes high-fluid-loss materials to plug and tighten existing fractures; and "Fracture Propagation Resistance" theory involves isolation of the fracture tip. The design and successful utilization of a blend of WSM based on the opening and sealing of fractures suggests that these three theories are, in many respects, complementary.
Any theory explaining a particular problem is ultimately judged by its practical application. Cashiriari field, known for expected mud losses to both natural and drilling-induced fractures in primarily permeable formations, is where this wellbore strengthening application took place. The optimum blend of particulates, designed using wellbore-strengthening (WBS) software, was applied consistently on the wells drilled by the operator in the Cashiriari field in the 2009-2010 campaign. Fracture resistance was increased up to 0.8 lb/gal above the minimum horizontal stress for drilling and up to 1.68 lb/gal for running casing and cementing operations. Specialized logs showing the presence of WSM inside fractures were an important tool for optimization of the WSM blend.
WSM design software takes in account a multitude of drilling parameters and rock properties to predict the fracture width and estimate the required size distribution and concentration of the WSM particulates. Consequently, the WBS solution reduced lost circulation as a primary contributor of costly and time-consuming lost circulation incidents in the Cashiriari field. Further, it is anticipated that as the WBS approach is applied more widely, the incidence of lost circulation events will be greatly reduced.
Cuttings Injection and Monitoring Operations: Cashiriari Gas Field, Peru III
Authors: Pierce D. , Dunlap L. , Suarz C. , Zaki K. , Elfayoumi A. , Loloi M. , Abou-Sayed A. , Marinello S. , Cassanelli J. P. 
Published: December 2010

Abstract
Performance and environmental assurance of cuttings injection programs require monitoring and periodic analysis of injection response. Such programs provide operational oversight and the ability to respond to changes in performance, providing for optimization of operating parameters to minimize potential negative impacts. Cuttings injection was implemented on a remote pad in the Cashiriari Field, located in a nature preserve in Camisea, Peru. CI was recognized as a technically and environmentally acceptable alternative for waste management in a location with extreme environmental sensitivity. Higher than anticipated injection pressures, indicative of regional and local stress regimes, required adjustments in operating parameters and expectations. Performance was contingent on successful inhibition of reactive clays in and around the target zones. Continuous monitoring of closure pressure and other trends associated with batch injection has made performance predictions possible. Monitoring operations have allowed for performance improvement and/or minimization of potential problems. The operation injected over 212,000 bbls of cuttings on the first pad and continues to be successful on the second pad through careful management of batch attributes and adaptation to operating realities. Assurance derived from such programs provides long term operational viability and social acceptance of cuttings injection as a safe means of waste management.
Selection Methodology for Screening Evaluation of Enhanced-Oil-Recovery Methods
Authors: Trujillo M. , Mercado D. , Maya G. , Castro R. , Soto C. , Pérez H. , Gómez V. , Sandoval J. 
Published: December 2010

Abstract
This paper presents a methodology for the selection of the enhanced oil recovery technologies that better applies to some group of fields using screening criteria. The methodology has been integrated in a software in order to make repetitive analysis in an easier way, and has been applied for identifying the technologies whit higher technical potential of application in the Colombian Fields which have the biggest amount of oil in place (approximately 80%). The methodology incorporates oil and rock properties and the reservoir current conditions, besides the specific knowledge of the reservoir generalities and history.
In some Colombian fields, processes that use water, gas or steam have been applied; additionally, some other projects using water, gas, chemicals and air are in a design stage at this moment, however, more than 90% of the approximately 280 Colombian fields are still in primary recovery. This is one of the main reasons for having an oil average recovery factor of about 21%, and it also states the need of using methodologies that allow identifying the best investment options. The technologies considered in this analysis were: water injection, lean gas, rich gas, N2, WAG, CO2 (miscible and immiscible), polymer, surfactant – polymer, steam (cyclic and continuous) and some others such as CHOPS, VAPEX, WET VAPEX, SAGD, in situ combustion and electromagnetic heating.
The application of the methodology presented in this study allowed to identify the enhanced oil recovery technologies with higher potential for being applied in the Colombian fields with biggest amount of oil in place; it also generated a guide for the construction of every analyzed field development plan, which is presented as an example for the Cocorná heavy oil field.
The subject treated in this paper is more important for companies that own an important number of fields, and need to identify those with better characteristics for enhanced oil recovery projects in a quick and easy way; however, it is also very useful for companies that are beginning to develop any specific field.
Production Allocation in Multi-Layers Gas Producing Wells Using Temperature Measurements
Authors: Rabie Reda , Daoud Ahmed , El-Tayeb El-Sayed , Dayem Mohamed Abdel 
Published: December 2010

Abstract
We present a methodology of allocating gas rate and associated water to each individual layer using temperature measurements and total surface production of gas and water. This paper consists of two parts. In part one; we propose an analytical forward model for wellbore temperature response under two-phase production in a multilayer geometry, using a nodal representation of the well. This model accounts for the formation geothermal gradient, steady-state gas-water flow in the wellbore, friction loss and Joule-Thomson effect in the wellbore, contrast in the thermal and physical properties of gas and water, wellbore heat losses due to unsteady heat conduction in the earth, and the mixing of the fluid streams of contrasting temperature. The second part shows the solution technique used to allocate the gas and water rate for each layer by knowing the temperature measurements inside the wellbore and by using the previously derived forward model for temperature response along with commercial software packages used to estimate the pressure loss required by the temperature forward model.
Two synthetic cases are used to test the validity of the new developed forward model; the first one is account for a well that produces from a single layer, while the second one produces from multilayer well in which the temperature in the wellbore and production rate is known. The developed model is applied to calculate the temperature profile inside the wellbore. The calculated profile is compared with the actual profile. The results showed that the new developed model is valid and reliable.
The practical implementation of the new developed production allocation model is examined on data from two actual gas wells with temperature measurements taken from Production logging tools recorded in these wells. The results showed that the model succeeded to accurately allocate the flow rate of gas and water phase for the multilayer producing wells based only on the temperature measurements inside the well bore and the total surface rates.
Hole Enlargement in Brazilian's Pre-Salt Reservoirs: A New Technology Frontier
Authors: Silva Leonardo P. , Paixão Diogo G. , Kishi Alcides R. , Silva Adriano R. 
Published: December 2010

Abstract
This work intends to show how important was this hole enlargement operation in that Pre-Salt well describing its obstacles and effectivity. This operation allowed both run and cementing of the last casing of this well. Thus, it was ready for testing and oil sampling of these Pre-Salt microbial reservoirs. Furthermore, it also shows the challenger scenario we will face in this kind of operation from now on. This underreaming job occurred in the X well of Campos Basin. Our purpose was to ream 30 meters of salt, which was easily flowing and reducing wellbore, and 55 meters of the microbial carbonate reservoir. This interval was oversized from 8 ½" to 9 7/8", in order to allow a combined liner run (7 5/8" × 7") and ensure its cementation quality. A caliper run indicated a 9 7/8" bore along this entire segment. The result was a quite success confirming the effectiveness of the technique to this kind of scenario. To reach this success, 4 underreamers were used. In soft formations one tool can ream over than 500 meters. For this well the mission was accomplished, but the industry has a big challenge to design cutters blocks with longer life capable to ream extremely hard formations. At that time, these tools should be developed and ready to support the big demand we will expect in these tough scenarios, once they allow larger both tubing and open hole gravel pack screens, increasing oil production.
Computational Fluid Dynamics for Enhanced Environment Protection and Water Management
Authors: Daas M. A. , Golczynski T. S. , Agrawal M. 
Published: December 2010

Abstract
The increasing demand for energy contributed significantly to recent developments in offshore production and transportation of oil and gas. Offshore oil spills are major threat to environmental safety and marine life. Damage control and preparedness planning require better understanding of oil spill process, trajectory, and how Metocean and atmospheric forces influence the spatial and temporal spread of oil in seawater dramatically.
Computational fluid dynamics (CFD) has proved to be an invaluable tools to analyze in detail the dispersion of pollutants, including oil, in sea shore area. However, CFD models for large scale domains, extending several kilometers offshore and along the coast, need grids with several millions of points to accurately predict the dynamic distribution of spilled oil. For such large scale domains, over simplification of the physical model or Metocean data may result in significantly different results. A detailed Computational Fluid Dynamics (CFD) based study is established to predict the trajectory of oil film during various spill scenarios in shallow water wave profile and the influence of wavelength and amplitude as well as current velocity. A three phase (Oil, water and air) Volume of Fluid (VOF) multiphase model in ANSYS FLUENT is used to capture the free surface and the motion of oil film.
It is found that in the absence of sea current effects, buoyancy of oil droplets is dominant, and the diffusion-advection on the surface continues to progress forming thick oil slick even in the opposite direction of the wave transmission. Higher wavelength (less frequent) are associated with less extent of oil dispersion since shorter waves (more frequent) will cause relatively more violent water flow near sea surface which can transport oil droplets further up in wave direction. Furthermore, waves of smaller amplitudes cause more spread of the oil slick, especially in the direction opposite to wave direction. This is because less amplitude waves are associated with less turbulence and breaking energy, and hence less dynamic vertical dispersion of oil film in seawater.
Multilateral Well Drilling Using Imaging Logs in Mature Field Near Tampico, México
Authors: López-Solís V. M. , Velázquez-Cruz D. , Espinosa-Castañeda G. 
Published: December 2010

Abstract
The recovery of hydrocarbons in Mexican reservoirs is decreasing and the need to produce oil of economic form becomes a major challenge for the Petroleum Engineering. Multilateral Wells are not a new concept; however, its successful implementation has increased in the last decade as they represent an alternative to develop new wells or complement previous conventional or unconventional wells into the field.
Mexico is a major oil and gas producer and near of 90 percent of its oil production comes from Naturally Fractured Reservoirs, generally with a good thickness. These natural conditions are favorable to use production schemes based on horizontal and multilateral wells to exploit the mature fields. Further, utilization of imaging logs to know the spatial distribution of fractures in the well, allows us to define the best trajectory of horizontal branches. The primary goal of branches is intersect the greater amount of natural fractures to augment the hydrocarbons volume recovered.
The present paper described our experiences during planning and drilling a dual-horizontal-multilateral well called Sinclair 313. Horizontal branches were drilled with underbalanced technique using a potassic-nitrogenous water based drilling fluid to minimize rock-fluid interaction and avoid lost circulation problems into depleted reservoir. Likewise, logs were taken using memory systems conveyed with drill pipe; both conventional petrophysics and imaging information, and imaging logs were analyzed to redefine trajectory of horizontal branch. Last, a brief operative procedure to reach the production zone is described and main benefits and key issues are outlined.
Residual-Oil Saturation for a Very Long Unconsolidated Core, With Live Oil at Reservoir Conditions
Authors: Moreno R. B. , Bonet E. J. , Iatchuk S. , Vieira M. R. , Correa A. C. 
Published: December 2010

Abstract
This study aims the determination of the residual oil saturation (ROS) for a Brazilian field through a laboratory displacement test. Constant rate of water injection was performed using a long core sample prepared with reservoir rock and field live oil. The core test was vertically positioned and submitted to temperature and pressure reservoir conditions. A complete test protocol description is presented here, as well as the results discussions and comparisons with literature approaches.
The measurement of Residual Oil Saturation is of paramount importance to predict the expected recovery in a producing field and is a key factor for reservoir management. Several techniques are available for ROS-Measurement; however cost and representativeness can vary among them. Core analysis is one of the most widely used methods and this current evaluation was focused on a very high productivity offshore field, where this parameter was object of controversy.
Real cores from the field were frozen and brought to the lab, where they were sampled, placed in a core holder and submitted to an overburden pressure. Conditions before and after overburden pressure application was scanned with CT. Separator dead oil was dehydrated and recombined with a known gas composition, according to the GOR measured in the field. The sample was saturated with water, followed by injection of high viscosity mineral oil to reach representative initial water saturation for the field. Finally, the sample was submitted to the injection of the live oil reservoir till the GOR was constant at the outlet of the core. Injection tests were performed and one is detailed described here.
Extensive evaluation of the test protocol is presented and the experimental results are discussed and compared with a mathematical model. As main contributions we can mention the successful preparation method for long cores from unconsolidated rock and the novel dehydrating process which has been patented.
An Integrated Methodology for Water Management Under Operational Restrictions
Authors: Muñoz Mazo Eduin O. , da S. Gaspar Ravagnani Ana Teresa , Barreto Carlos Eduardo , Schiozer Denis José 
Published: December 2010

AbstractThe current concern with the increasing amounts of produced water and the wide variety of operations in which water takes place require considering strategies that, with their further development and implementation, lead to a correct management of the produced and injected water in order to increase the oilfield productivity. Thus, it is possible to determine operation conditions regarding the settings that allow optimizing the oil recovery and the economic incomes of an oil E&P development.It is known that efficient strategies for water management can lead to an effective control of the influence of water on the project development, increasing the economic performance of oil production by means of the reduction of costs and/or the increase of revenues in the cash flow. Examples of this situation are the anticipation of the oil production, the reduction of the treated volumes of water in the field and their respective costs, besides the increase in final oil recovery.Hence, the determination of limits for the water production and injection, the dimensioning of surface facilities and the selection of the proper options for water management shall be based on the economic parameters and production performance, since the handling of an eventual extremely high water production, or an injection not agreed with the necessities of the field and the processing capacity, can affect negatively both, the cash flow and the final oil recovery. Also, it is important to highlight that the strategy selected for water management must consider environmental actions not only to minimize the negative effects of water processes, but also because those actions can be accounted for into the cash flow and in the field operation as intangible goods.This paper presents a brief review on the main aspects of the water management and proposes a methodology which integrates different factors involved in water management to determine the appropriate conditions for its implementation, considering technical and economic factors. The study presents as main benefit the possibility of an integrated solution in order to get a bigger performance of the processes that involve the use of water in oil field operations.