bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tractoring – A New Era in Horizontal Logging for Ghawar Field, Saudi Arabia
Authors: Al-Amer A. A. , Al-Dossary B. A. , Al-Furaidan Y. A. , Hashem M. K. 
Published: December 2007

Abstract
The number of horizontal wells is increasing dramatically in Ghawar Field, the largest onshore oil field in the world. Refer to Figure-1. The complexity of completions is also increasing. Horizontal wells and complex completions such as extended reach and multilaterals introduce challenges for conventional intervention techniques such as coiled tubing (CT) to convey diagnostic and surveillance tools to the bottom of these wells. One answer to this challenge is the intelligent deployment system known as wireline tractoring.
The wireline tractor provides a breakthrough in logging capability by being able to log successfully where conventional wireline and CT logging tools cannot go. This paper will highlight challenges and Saudi Aramco's experience in production logging extended reach (1.5 - 3 km) open hole horizontal wells using two different types of tractoring devices. The characteristics of the two tractors will be described and compared, and the benefits of applying this technology will be explained in detail. The paper will discuss the successful application of this technology and its comparative advantages, including reduced cost and enhanced operational safety. Discussion of the collaborative work among various Saudi Aramco organizations and service companies in deploying this technology will also be presented. This success story of using the wireline tractor to deploy production logging tools in Ghawar Field will illustrate Saudi Aramco determination to overcome challenges by applying the best available technology.
Inflatable Enables Successful Water Shut-Off in High Angle Wellbores in Ghawar Field
Authors: Al-Umran M. I. , Saudi M. M. , Al-Tameimi Y. M. 
Published: December 2007

Abstract
A major challenge in today's oil field industry is to minimize the amount of water produced. Fortunately, many strategies and solutions are currently available; some involve mechanical tools while others use chemicals to manage unwanted water production.
This paper describes the successful application of rigless water shut-off in highly deviated well bores using inflatable plugs set by coiled tubing and with cement placed on top to reduce excessive water production. This technique was successfully employed to reduce water production and revive dead wells in Hawiyah area of the Ghawar field.The primary focus of this paper is to highlight the challenges and share Saudi Aramco experience in performing cost-effective mechanical water isolation in highly deviated wells.It is critical that the nature of the water production problem be fully understood to achieve successful water isolation.
Horizontal or deviated wells might die or produce excessive water after initial completion or after a short period of production due to high water flow intervals. A rigless solution was successfully performed on three dead wells utilizing inflatable plugs.The plug was run in hole using coiled tubing and then was capped with cement.The jobs yielded excellent results in reducing water production and re-activating these wells.The payout period for each job was less than one day. Based on these results, many additional candidates are now being evaluated for possible application.The challenges and risks encountered in previous unsuccessful water isolation attempts included premature setting of the plug in tubing nipples, failure to disconnect from the CTU after setting, or the well remaining dead after the job.This paper describes how a fit-for-purpose solution was planned to overcome these challenges through careful collaboration with the service company to develop the optimum procedure for the job.Also described are the benefits that resulted from this process, including well intervention without pulling the completion, elimination of kill fluids to minimize formation damage, and workover rig cost savings.
Field Example of Capillary Pressure Effects on Wireline Formation Tester Measurements and OWC Estimation in a Mixed-Wettability Oil Reservoir
Authors: Pham T. R. , Al-Afaleg N. I. , Kelder O. , Al-Otaibi U. F. , Zeybek M. 
Published: December 2007

Abstract
This paper discusses a field example of capillary pressure effects on down hole formation tester pressure measurements and oil-water contact estimation. Capillary pressure effects are investigated as functions of mud invasion, mobile formationwater, and rock wettability. Specifically, the effects of mudfiltrate invasion on formation tester probe pressures are quantified in terms of the error margin on the oil-water contact estimate.
In the field example, a fluidpressure gradientof about .45psi/ft was established from the bottom to the top of the reservoir, which is indicative of a water bearing formation. On the other hand, bottom hole fluid samples with the Modular Formation Dynamics Tester (MDT™) showed a 100%oil recovery in shallow intervals, moderate oil-cut recovery in the intermediate intervals, and lowoil-cut recovery in the deep intervals.
The purpose of this paper is to use formation tester information from the field example well, offset delineation wells, and reservoir behavior information, to support and explain that the apparent gradient in this case is not a true representative of the fluid gradient in the reservoir, rather, it represents the water phase gradient created by filtrate invasion and mobile water. A simulation model was developed, based on reservoir properties and laboratory measured capillary pressures, to simulate the formation saturation as a function of mud filtrate invasion and mobile water. Log-derived water saturations were used as a guidance, and ultimately, the model was used to predict the apparent pressure readings by the formation tester.
Together with the understanding of reservoir behavior derived from the simulation model, field data from all delineation wells were used to define the effects of mud filtrate invasion on formation tester pressure measurements. Consequently, the error margin on the oil-water contact estimate is benchmarked. Based on the field evidence,the paper also discusses which methodology is most accurate to use in the oil-water contact delineation in the field area of interest.
Simultaneous Analysis of Total Alkalinity and Organic Acid in Oilfield Brine
Authors: Tomson M. B. , Kan A. T. , Fu G. , Wu X. , Al-Thubaiti M. , Kirk J. , Martin R. , Prukop G. , Inan E. Esra , Davis S. T. 
Published: December 2007

Abstract
Measurement of bicarbonate in produced waters is necessary to calculate thepH for corrosion estimation and for several types of scale predictions, carbonates, sulfides and oxides. Generally, bicarbonate is the predominantbuffer in produced salt water, yet it is difficult to measure accuratelybecause of gas/solution and solution/solid exchange. When sulfides and weakcarboxylic acid buffers, such as formic, acetic, and propionic acids are alsopresent, the problem is complicated both experimentally and theoretically. Wehave recently developed a rigorous theoretical solution of this problem andproposed a corresponding experimental method to accurately measure bothbicarbonate and weak acids simultaneously with minimal experimental difficultyand costly instrumentation. In addition, the sample becomes its own standard.Practically, the method requires a new software package, written in Excel, todo the calculations. After extensive testing using synthetic brines of our ownand field brines supplied by several companies, a series of blind round-robintests have been conducted using only field brines. Several production andservice companies in our Brine Chemistry Consortium have participated in theround-robin testing. In order to estimate accuracy we analyzed the brines usingseveral methods. The precision and accuracy of these blind tests have exceededour expectations, generally approaching ± 3 %. The methodology is presentedalong with the statistical analysis and recommendations for use.
Modeling of Tubing Pickling in Conjunction with Acidizing Treatments
Authors: Al-Mutairi S. H. , Hill A. D. , Nasr-El-Din H. A. 
Published: December 2007

Abstract
Pickling well tubulars to prevent pumping unwanted materials into the formation is an issue that should be decided on an individual job basis. Acid pickling of tubing is a process of flow in a tube or annulus with heterogeneous reactions occurring at the wall of the tube. The reacting solid species at the wall are primarily mill scale, pipe dope, and other scales of various types. The fluids injected for pickling are usually strong acid solutions (HCl), but may also include surfactants, organic solvents, and gelled solutions to aid in lifting solids loosened from the tubing wall. Thus, the process is a complex one involving several reactions with perhaps multiple stages of fluids.
Tubing pickle is an essential part of well stimulation treatments if the main acid job is to be bullheaded. Standard design parameters for a pickle treatment depend on experience and personal judgment. It appears that the standard pickle treatment design is overestimating the required volume of pickling acid. Field data indicate that excessive acid volumes are used for tubing pickle because large returns of unreacted (live) acid are usually recovered on the surface. Careful analysis of flowback samples showed that only a fraction of the acid is being consumed by mill scale and other tubing contaminants.
In this paper, proposed mechanisms to explain the behavior of acid contact with the tubing are presented and a mathematical model for predicting acid consumption and dissolution of tubular contaminants is developed. The model is developed for the bull-heading case where the pickling acid is pumped down the tubing, then flowed back to the surface. The model considers the reaction of acid with mill scale (Fe3O4). The equations formulated are solved numerically to predict the concentrations of major chemical species as a function of position along the tubing and in the effluent from the well during flowback.
Such a model can be extremely valuable in optimizing the application of future pickling treatments. Using this model, the acid volume needed for pickling operations can be reduced significantly and other improvements can be made without extensive, costly field testing. Finally, some recommendations are made to design optimum pickling treatments.
A Front-Tracking Method for Efficient Simulation of Miscible Gas Injection Processes
Authors: Juanes R. , Lie K. -A. 
Published: December 2007

Abstract
This paper presents a front-tracking method for the numerical simulation of first-contact miscible gas injection processes. The method is developed for constructing very accurate (or even exact) solutions to one-dimensional initial-boundary-value problems in the form of a set of evolving discontinuities. The evolution of the discontinuities is given by analytical solutions to Riemann problems. A complete analytical Riemann solver is presented along with methods for simplifying the wave structure for Riemann problems of small amplitude. Several representative examples are used to illustrate the excellent behavior of the front-tracking method.
The front-tracking method can be extended to simulate higher-dimensional processes through the use of streamlines. The paper presents an application of this computational framework for the simulation of miscible flooding in a three-dimensional, highly heterogeneous formation, and demonstrate that a miscible water-alternating-gas injection scheme is more efficient than waterflooding or gas injection alone.
Fractured Reservoir Characterization Using Dynamic Data in a Carbonate Field, Oman
Authors: Ozkaya S. I. , Richard P. 
Published: December 2007

Abstract
The main objective of this study was to extract fracture data from multiple sources and present it in a form suitable for reservoir simulation in a fractured carbonate field in Oman. Production is by water injection. A combination of borehole image logs and openhole logs from horizontal wells revealed that water encroachment is mostly through fracture corridors and appears as sharp saturation spikes across fracture clusters. Dispersed background joints have little flow potential, either because of cementation or lack of connectivity or small size. Image logs indicate fracture corridors are oriented dominantly in WNW direction. Most of the several injector-producer shortcuts are also oriented in WNW direction supporting the view that fracture corridors are responsible for the shortcuts.
Flow meter logs from vertical injector or producer wells intersecting a fracture corridor show a step profile. A comparison of injection or production history of wells with or without a step profile provided a means to calculate permeability enhancement by fracture corridors. The field has over 300 vertical and nearly 20 horizontal wells, which allowed us to generate detailed fracture permeability enhancement and fracture corridor density maps based on injector and producer data, shortcuts, mud losses, openhole logs and borehole image logs. We were able also to build stochastic 3D fracture corridor models using corridor density from dynamic data and orientation from borehole image logs and seismic data. Fracture corridor length and width were tied to fracture permeability enhancement using wells with both image logs and production data. The fracture permeability enhancement maps were independently verified by water flood front maps. Notwithstanding the uncertainties, the fracture data was sufficiently accurate and detailed to generate both single and dual porosity simulation results with good field scale history match.
Orientation and Career Development for New Engineers
Authors: Talabani S. 
Published: December 2007

Abstract
Training new engineers for any industry is not an easy task. It is also the most important task for the company to invest effort and money in, because the new engineers today will be the managers of the future.
Incapable engineers with insufficient backgrounds in training will therefore lead the company to make disastrous mistakes in planning and management. Consequently, it is important to put serious efforts into training new engineers by appointing either the right training staff within the company, or the right company responsible for managing the training plans in detail. Training plans should be reviewed by both sides. The company "that the engineer belongs to" should identify the right position for the engineer in the company. This is not a one-sided decision and should rather be made by involving the engineer. The engineer should have a taste of the position and enjoy doing the work. The company, on the other hand, should ensure that the position suits the engineer.
Knowledge of the company's heritage by the employees is as important as their tasks. Knowing the company's structure helps an employee recognize their position within the company.
A new employee should be advised that their education should start from day one in the company by keeping up to date with the latest research and studies conducted all over the world. In this paper, a detailed plan for training new engineers, phases a company should follow for training, what supervisors should be looking for, and how to periodically improve training programmess are addressed.
The SURE way to Underbalanced Drilling
Authors: Qutob H. , Ferreira H. 
Published: December 2007

Abstract
The benefits of UnderBalanced Drilling-UBD are now widely understood and revealed. However, the impact of UBD on well productivity/injectivity is still elusive. Few papers have documented historical applications of UBD and a recent focus has been to quantify UBD benefit through productivity increase comparisons, or productivity improvement factors-PIFs against field averages. Yet, comparative analyses are questionable.
A process named Suitable Underbalanced Reservoir Evaluation (SURE) has been developed to identify UBD prospects and to quantify the potential well productivity/injetivity benefits of a UBD operation. SURE is a simple, fast and reliable way to accurately evaluate the suitability of an UBD operation for reservoir performance.
A Comparison Study on Experimental Design and Response Surface Methodologies
Authors: Yeten B. , Castellini A. , Guyaguler B. , Chen W. H. 
Published: December 2007

AbstractExperimental design method is an alternative to traditional sensitivity analysis. The basic idea behind this methodology is to vary multiple parameters at the same time so that maximum inference can be attained with minimum cost. Once the appropriate design is established and the corresponding experiments (simulations) are performed, the results can be investigated by fitting them to a response surface. This surface is usually an analytical or a simple numerical function which is cheap to sample. Therefore it can be used as a proxy to reservoir simulation to quantify the uncertainties.Designing an efficient sensitivity study poses two main issues: Designing a parameter space sampling strategy and carrying out experiments.Analyzing the results of the experiments. (Response surface generation)In this paper we investigate these steps by testing various experimental designs and response surface methodologies on synthetic and real reservoir models.We compared conventional designs such as Plackett-Burman, central composite and D-optimal designs and a space filling design technique that aim at optimizing the coverage of the parameter space. We analyzed these experiments using linear, second order polynomials and more complex response surfaces such as kriging, splines and neural networks. We compared these response surfaces in terms of their capability to estimate the statistics of the uncertainty (i.e., P10, P50 and P90 values), their estimation accuracy and their capability to estimate the influential parameters (heavy-hitters). Comparison with our exhaustive simulations showed that experiments generated by the space filling design and analyzed with kriging, splines and quadratic polynomials gave the greatest accuracy while traditional designs and the associated response surfaces performed poorly for some of the cases we studied. We also found good agreement between polynomials and complex response surfaces in terms of estimating the effect of each parameter on the response surface.
The Development of an Optimal Grid-Coarsening Scheme: Interplay of Fluid Forces and Higher Moments of Fine-Scale Flow Data
Authors: Darman N. H. , Sorbie K. S. , Pickup G. E. 
Published: December 2007

Abstract
The accuracy of upscaling procedures can be improved by using non-uniform grid cells at the coarse scale level. Several researchers have investigated objective methods of selecting the optimal coarse grid configuration for a particular fine grid model1–2. However, all of these works neglect the effect of fluid force balances and always assumed the model to be in viscous dominated flow. This paper describes a new optimal grid-coarsening scheme for two-phase flow in porous media based on the quantitative use of fine-scale simulation data. The main idea of this approach is to use fine-grid fluctuating moments to guide the choice of the coarse grid structure. These quantities are derived from the volume average saturation equation for different fluid force balances i.e. viscous, gravity and capillary. It is shown that this approach results in a more accurate prediction of quantities such as total oil recovery and fluid production ratio in coarse grid models.
Here, we explore the relationship between the sub-grid properties described above, and coarse scale numerical simulations for several synthetic model problems. To do this, we first introduce capillary terms into the volume averaging equations3 to allow us to assess the coarse scale simulations when capillary pressure is important in the fine grid models. Then we proceed to the two-stage testing of the proposed technique to study the relationship of sub-grid variability to the error in the coarse scale simulation results. In the first stage testing, we consider many different aggregations of 2D, 20-layer fine grid systems to equivalent 2-layer coarse grid systems and in the second stage testing, we then apply our findings to more heterogeneous interbedded sand cases where capillary forces are more important and consider coarsening the fine grid model to more than 2 layers.
A New Method for Profile Control with Compound Ion Gel before Polymer Flooding
Authors: Liu H. , Wang J. , Yang Y. , Wang F. 
Published: December 2007

Abstract
It is well known that extensive profile control can enlarge sweep area and enhance displacement efficiency in reservoirs with inner-layer and inter-layer interferences. As for Daqing oilfield, the heterogeneity is very serious in vertical direction. After a long term of water flooding, big channels were formed in many layers. In order to improve the development efficiency, an extensive profile control with compound ion gel was performed before the polymer flooding. This profile control technique was tested in some pilot areas. The treatments have achieved good results in increasing oil production and decreasing water cut. The application results indicate that profile control with compound ion gel is one of the most effective methods that can improve development efficiency of polymer flooding.
An Assessment of Emerging Technologies for Production Optimization in Saudi Aramco—Southern Area Production Engineering
Authors: Vo L. , Styler J. W. 
Published: December 2007

Abstract
In the petroleum industry, advances in technology continue to make a great impact on the business environment. Within the last decade, many emerging technologies have transformed the way oil and gas companies manage and optimize their operations. Today it is widely recognized that significant new oil fields are hard to find and aging oil fields are becoming more challenging and costly to operate. Emerging technologies fill a critical need in the fight against relentless production decline and rising operating costs.
In this regard, Saudi Aramco is no exception, even though it operates some of the largest oil and gas fields in the world. Aside from its routine production related initiatives, the company has invested a significant sum in new technologies with the goal of maximizing production and minimizing capital investment and operating costs over the long term. This paper will provide an assessment of new technologies that Saudi Aramco Southern Area Production Engineering (SAPED) has been working on over the past several years to meet this objective. Each of the applications discussed has either already yielded or is expected to yield significant benefits in terms of productivity improvement/operational enhancement, data management/reservoir optimization, or safety. A brief description of each technology is presented from a Production Engineering perspective.