bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increasing Production with an Innovative Through Flow Line (TFL) Multi-Zone Completion Design for a Major Norwegian Operator
Authors: Østvik Egil , Hansen Helge Bjorna , Rasmussen Lars , Malmanger Eva Mette , Hydro Norsk , Tønnessen Sven Harald , Browne Paul L. , Williamson Jim 
Published: December 2007

Abstract
Norsk Hydro operates the Snorre Field in the Norwegian sector of the North Sea with a tension leg platform (TLP) and a sub-sea production system. The initial sub-sea wells were designed with completions that would allow through-flow-line servicing, and while the wells were functioning as designed, production had been declining. Therefore, Norsk Hydro felt that the completion concepts should be evaluated for new field developments. The ensuing investigation and development project led to a novel well completion concept, which is the first "intelligent well" subsea completion installation offshore Norway.
This innovative design changes retain the original through-flow-line (TFL) service technique system and subsea infrastructure without any modifications, maximize production by introducing 7-in. tubing, and include hydraulically operated inflow control devices.
The supplier and operator developed the concept during the winter 1998/1999 and designed the resulting system during spring 1999.
License approval for prototype development and qualification was given in the summer of 1999, and the system components were in-house tested at the supplier base in Dallas during the fall of 1999. A thorough system qualification was performed at an independent Norwegian drilling and well test center during spring/summer of 2000. The qualification included a full test-well installation and necessary intervention activities to prove the functionality of the concept. The system was qualified during the summer of 2000. The first subsea well installation was done at Snorre and put on production in December 2000. The well completion consisted of a 4-zone/interval design for improved reservoir management.
The concept principles also have application for other type wells on platforms where modifications to the wellhead and tree are not feasible.
The development process and qualification of the system has been conducted in a very short time period from idea to offshore implementation. This is mainly the result of a very focused personnel team with competent and dedicated personnel between supplier, operator, and 3rd party testing contractor.
This paper will discuss the improved system and testing that resulted from this project. The first new production system was installed in a side-tracked well, and the results of the completion will also be discussed.
Design and Deployment of an Intelligent Completion with Sand Control
Authors: Bixenman P. W. , Toffanin E. P. , Salam M. A. 
Published: December 2007

AbstractEarly results from intelligent completion installations show great promise for production optimization and control. The intelligent completion flow control valve is typically installed between isolation packers within the production zone. There have been installations with as many as four zones containing intelligent flow control devices. Several installations of intelligent flow control equipment have been in wells that require sand control, but these installations did not allow placement of the flow control devices within the production zone. The zones are completed with traditional sand control techniques, with each zone gravel packed or frac packed. After the sand face completion is in place, an upper completion is run into the well with a siphon string stabbed into the lower zone. A valve in line with the siphon string controls production from the lower zone. Production from the upper zones flows through the annulus between the siphon string and the upper completion into the casing annulus above the uppermost gravel-pack packer. A flow control valve is used to control the flow from that casing annulus into the production tubing. In this type of configuration, the practical limit for zones that can be controlled is two. An alternative technique has been developed that allows the placement of the flow control device within the production zone, so that more than two zones can be completed with intelligent flow control devices. As is the case for an intelligent completion in a cased and perforated well without sand control, the entire completion is run in one trip. Once the completion is in place, all of the intelligent completion devices are tested and then the packers are set. A through-tubing sand control tool is then run into the completion to perform the gravel packing operation in each zone. The paper discusses the completion design and presents an example of a field installation.
The Use of Fiber-Optic Distributed Temperature Sensing and Remote Hydraulically Operated Interval Control Valves for the Management of Water Production in the Douglas Field
Authors: Tolan Michael , Boyle Maurice , Williams Glynn 
Published: December 2007

Abstract
Unwanted water production has long been one of the biggest problems that the oil and gas industry has had to address in efficiently producing hydrocarbons. This paper describes how fiber-optic-distributed temperature sensing (DTS) has been used in conjunction with remotely operated hydraulic interval control valves (ICVs) as an economical management tool for controlling water encroachment. Used with intelligent well technology, this method provides interventionless control and selectivity of producing intervals using surface-actuated hydraulic ICVs so that unwanted water production can be managed more effectively to maximize oil recovery. Distributed temperature measurements at one-meter intervals in the wellbore provide data that assists in the determinations of zonal contribution and the identification in the change of fluid properties or water ingress.
This method was installed on the Douglas Platform in Liverpool Bay, United Kingdom. The completion was comprised of an ESP pump, hydraulic on/off disconnect, retrievable packers with hydraulic feed throughs and hydraulic ICVs. An optical fiber that acquires continuous distributed temperature data is installed into one of the hydraulic control lines that operate the hydraulic ICVs. Opto-electronic instrumentation on the platform allows distributed temperature data to be transmitted in real-time to a shore-based asset team.
The combination of fiber optics and hydraulic interval control valves provides a number of benefits:
The number of penetrations through tubing hangers and packers are reduced if required The fiber optic sensor is capable of gathering realtime logging data from multiple intervals without intervention The ICVs provide interventionless zonal control The disconnect system facilitates ESP workover and recompletion.
Hydroxyaminocarboxylic Acids Produce Superior Formulations for Matrix Stimulation of Carbonates at High Temperatures
Authors: Frenier W. W. , Fredd C. N. , Chang F. 
Published: December 2007

Abstract
Hydroxy-aminocarboxylic acids (HACA) including hydroxyethylethylenediaminetriacetic acid (HEDTA) and hydroxyethyliminodiacetic acid (HEIDA) possess some unique chemical characteristics. The most significant attribute is high solubility in acidic solutions; in addition, HEIDA is biodegradable. Other conventional chelating agents, such as ethylenediaminetetraacetic acid (EDTA) become insoluble in acid at pH values &lt; about 4.0 and EDTA is slightly (0-5% depending on the test) biodegradable. The unusual characteristics of the HACAs have enabled the formulation of unique acidizing and scale removal systems that are being employed for cleaning and stimulating oil and gas wells.
In this current paper, we will describe the continuing development and testing of HACA materials as components of matrix acidizing formulations for stimulating carbonate formations at very high temperatures (400 °F). The pioneering work of Fredd and Fogler (SPEJ, 4(3) 1999) demonstrated that organic acids and chelating agents have unique attributes that lend themselves to efficient production of wormholes in many acidizing situations. We have applied the same techniques for determining transport and reaction kinetics, to stimulation fluids containing hydroxy amino chelating agents. Linear core-flood tests were used to study wormhole formation and rotating disk tests with calcite samples were employed to elucidate the kinetics and mechanisms of the dissolution over a temperature range of 65 to 400 °F. Carbonate formations are very difficult to stimulate at these high temperatures because mineral acids react much to fast to produce dominant wormholes, and are difficult to inhibit (corrosion control).
In addition, these new fluids will not require iron control agents to be added (they are effective iron complexers), and are easily inhibited to high temperatures (up to 400 °F) using minimal amounts of corrosion inhibitors.
NMR Measurements in Carbonates Samples and Core-Logs Correlations Using Artificial Neural Nets
Authors: Salazar J. P. , Romero P. A. 
Published: December 2007

Abstract
The Mara West Field reservoir in the Maracaibo Lake presents some challenges in petrophysical evaluation, which are related to the determination of the water saturations, porosities and permeabilities. The information extracted from conventional log data is not sufficient to fully evaluate the formation. This is due to the fact that these logs are affected by the presence of carbonates, difficulting the evaluation of porosities and other properties. In order to overcome this problem, Nuclear Magnetic Resonance technique has been used in the evaluation of core plug samples and further core logs correlations. Its advantage lies in the measurement of porosity independently of lithology and pore distribution and in the calculation of permeability using parameters such as Nuclear Magnetic Resonance porosity, T2 cutoff, free fluid index and bound water volume.
The present work shows a very good correlation between Nuclear Magnetic Resonance data and conventional data extracted from core plug samples. It also shows how the implementation of a new equation for the estimation of permeability, provides an increment of the correlation coefficient from 0.36 to 0.81 obtained from the Nuclear Magnetic Resonance permeability Vs Klinkemberg permeability plot.
In order to complete the log information in the cored well and in a neighbor well, Artificial Neural Nets based on the backpropagation algorithm have been applied, generating the so called pseudologs (synthetic logs). To obtain the pseudologs of NMR porosity, gamma ray, resistivity and neutron logs have been used as input, while the core plugs value for NMR porosity and permeability as output. The results show a very good match between the existing data and the artificial neural net output in the validating data set.
A Model-Based Interpretation Methodology for Evaluating Carbonate Reservoirs
Authors: Ramakrishnan T. S. , Ramamoorthy R. , Fordham E. , Schwartz L. , Herron M. , Saito N. , Rabaute A. 
Published: December 2007

Abstract
Carbonate rocks are diverse, and their pore space complex. Petrophysical evaluation of carbonates with techniques developed for siliciclastic environments often fall short.
In this paper, we present a new methodology that combines diverse texture and facies sensitive measurements. The method parametrizes the pore structure in terms of a multiporosity system of fractures, vugs, inter- and intra-granular porosities, and evaluates the parameters from the measurements. The process is based on physics and relies minimally on empirical correlations.
The first step is to separate the fracture from the matrix using borehole images and then quantify mineral volumes and porosity through nuclear magnetic resonance (NMR) and/or nuclear logs with new mineral standards. Next, we classify the lithology with a self-organizing-map (SOM) algorithm using a vector of log-inputs. Following this, the vug fraction is estimated using shear modulus data and borehole image analysis. Finally, we separate the inter- and intragranular components using NMR data. This analysis includes molecular diffusion between different pore types. The NMR processing scheme also depends on lithology. The porosity components and the relevant length scales enable us to predict resistivity and permeability using an effective medium theory in an internally consistent manner.
Our interpretation methodology was validated successfully with core/log data from the Middle East. The facies ranged from mudstone to grainstone.
Utilizing Magnetic Resonance Logging for Improved Formation Evaluation in the Mediterranean Thinly Laminated Gas Bearing Formations: A case Study
Authors: Nashaat Mohamed , Sallam Yassin , Elsherif Ahmed 
Published: December 2007

Abstract
The Mediterranean is considered the future frontier for the gas development in Egypt. Rashid Petroleum Company (RashPetco) has recently achieved good results in the Mediterranean where a gas bearing formation was discovered and evaluated using the latest technology in formation evaluation. Standard open-hole measurements were used for porosity and water saturation estimation.
Recently, several wells were drilled and evaluated using the conventional methods. In one of the wells, an interval was evaluated as a body of shale and silt. The standard measurements gave no indication of pay zone in this body and it was not considered to contribute in the estimation of the total reserves. This body was reevaluated using the high-resolution technologies of Magnetic Resonance and Borehole Imaging measurements. Sandstone laminations were discovered and properly evaluated. The productivity of the sand streaks was established through the high-resolution permeability of the Magnetic Resonance logging. This productivity was proven by the utilization of Packer Module formation tester. The body was tested and was proven to be productive. Because of the new interpretation, the net pay was re-calculated in this shale body and was added to the total pay. Consequently, an increase in the proven gas in place was achieved. The technique of Density Magnetic Resonance (DMR) was used to properly evaluate the formation porosity and permeability.
Moreover, a water bearing sandstone was re-evaluated using the Magnetic Resonance logging and was proven to have residual gas which confirmed the surface seismic results. This confirmation changed the strategy for future drilling in British Gas.
The Integration of Capillary Pressures and Pickett Plots for Determination of Flow Units and Reservoir Containers
Authors: Aguilera R. , Aguilera M. S. 
Published: December 2007

Abstract
The concept of flow (or hydraulic) units and reservoir containers has been used in the oil industry with a good deal of success during the last few years. The process or delivery speed k/f can be used in many instances to define a flow unit. Correlation of flow units between wells helps to establish reservoirs containers and to forecast reservoir performance.
This study shows that a Pickett crossplot of effective porosity vs. true resistivity (in some cases apparent resistivity or true resistivity affected by a shale group) should result in parallel straight lines for intervals with constant process speed k/f. The slope of the straight lines is related to the porosity exponent m, the water saturation exponent n, and constants in the absolute permeability equation. From the straight lines it is possible to determine directly capillary pressures and pore throat apertures for each flow unit at any water saturation. Pore throats at 65% water saturation compare very well with Winland r35 values. The method has not been published previously in the literature.
Building lines of constant k/ϕ allows displaying complete capillary pressure curves on the Pickett plot including regions that are and are not at irreducible water saturation. Previous empirical methods for determining absolute permeability of a given interval assume that the water saturation is at irreducible conditions.
This paper presents a technique that allows estimating absolute permeability even if the interval contains moveable water.
The use of this technique is illustrated with previously published data from the Morrow sandstone in the Sorrento field of Southeastern Colorado and carbonates from the Mission Canyon formation in the Little Knife field of North Dakota.
It is concluded that flow units can be determined reliably from the integration within one single log-log graph of Pickett plots, capillary pressures, pore throat apertures and Winland r35 values. The correlation of the flow units between wells leads to the definition of reservoir containers.
Effects in the Determination of Oil Reserves Due to Gravitational Compositional Gradients in Near-Critical Reservoirs
Authors: Jaramillo Juan M. , Barrufet Maria A. 
Published: December 2007

Abstract
Several factors, such as gravity, temperature, type of reservoir fluid, geological structure, accumulation process, etc., may have important effects on the spatial compositional variation of hydrocarbon fluids in reservoirs.
Compositional gradients, which may be considerable in near-critical reservoirs, can have a profound impact on the estimation of initial in-situ hydrocarbons, the prediction of oil/gas contact location (OGC), and more important on the reservoir development strategies.
Some reservoirs have producing intervals with thickness that cover hundreds of meters from top to bottom, and sometimes even more than 2,000 meters. Over such a thickness, due to gravitational segregation, the mole fraction of the lighter components decreases with depth, while the mole fractions of the heavier components increase from the top to the bottom of the reservoir. Modeling the thermodynamic behavior of these fluids requires a properly tuned EOS capable of reproducing the available PVT data and the gravitational compositional gradation.
We studied a volatile oil from the Cusiana Field in Colombia. PVT reports consisting of constant composition expansion (CCE) and constant volume depletion (CVD) tests were used to calibrate the fluid mo del and the EOS parameters. We used the Peng Robinson EOS with volume translation and Whitson's methodology for defining and characterizing the pseudocomponents.
The result of this study addresses the discrepancies in original hydrocarbon volumes that take place when the compositional gradient is not considered. Without considering a compositional gradient, the original oil and gas in place can be either over or underestimated depending upon the depth at which the sample is taken. We show that we can select a reference sample composition, corresponding to a certain depth, such that this can be used without compositional gradient and the estimates of the original hydrocarbons in place are equivalents to those obtained with compositional gradient.
We provide guidelines and procedures to evaluate the effect of isothermal gravitational compositional gradient in the determination of in-place hydrocarbon content for volatile oil and gas condensate reservoirs.
Pulsed Neutron Spectroscopy Handles Saturation Monitoring In Complex Lithology Long Cased Hole Horizontal Production Wells
Authors: Borch Carsten , Whittaker Andrew Colin 
Published: December 2007

Abstract
The Siri Field on the Danish Continental Shelf is characterized by low-resistivity pay and porosities exceeding 30 PU. The reservoir sands are fine to very fine grained, well sorted with abundant iron-rich glauconite and chlorite. The microporous glauconite reduces the effective porosity and permeability and causes high initial bound water saturations.
Reservoir drainage is based on water and gas flooding (SWAG injection). Producing field water-cut increases rapidly in the horizontal producers due to severe bottom aquifer coning and later injection water breakthrough. The oil production rate is constrained due to limited liquid handling capacity. Water management is hence, a primary focus area.
Prior to initiating remedial workover operations, wireline tractor conveyed production inflow profiles and pulsed neutron capture gamma ray surveys were acquired.
In sigma saturation monitoring a pulsed neutron source allows the decay rate of capture gamma rays to be measured. The decay rate is inversely proportional to the formation sigma, which is a linear combination of the sigma values of the rock matrix and fluid filled porosity. Knowing the matrix sigma, oil sigma, water sigma, and total porosity, the log sigma can be converted to formation saturation.
The complex mineralogy of the reservoir sand with abundant and variable amounts of iron-rich glauconite significantly impacts the matrix sigma. Before sigma saturation interpretation can be made, the lithology needs to be determined more accurately than possible from standard open hole logs. A novel through casing pulsed neutron logging technique permitted well lithology determination. Using the spectral signal of the pulsed neutron capture gamma rays, a number of key matrix elements were quantified, converted to a matrix lithology, and then finally combined into a synthetic matrix sigma.
This paper describes, how a single pulsed neutron tool operated in two modes (spectroscopy and sigma) permitted quantitative lithology interpretation and saturation monitoring in a complex formation environment.
Advances in LWD Nuclear Magnetic Resonance
Authors: Drack E. D. , Prammer M. G. , Zannoni S. , Goodman G. , Masak P. , Menger S. , Morys M. 
Published: December 2007

Abstract
A second generation of LWD Nuclear Magnetic Resonance (NMR) tools has been developed and commercialized. These MRI-LWD* (Magnetic Resonance Image - Logging While Drilling) tools extend the technology by providing key improvements in data quality and operational efficiency. Improvements include: automatic mode switching, better vertical resolution, improved signal-to-noise ratio (SNR), real-time data transfer, built-in log quality control, increased battery life, and extended environmental ratings.
The paper also examines the context for the deployment of this system and the expanding role of NMR in formation evaluation. MRI-LWD belongs to a family of NMR tools which includes logging-while-drilling, wireline open-hole logging, formation testing/fluid sampling, and laboratory core analysis.
The Use of Real-Time and Time-Lapse Logging-While-Drilling Images for Geosteering and Formation Evaluation in the Breitbrunn Field, Bavaria, Germany
Authors: Rohler Hendrik , Bornemann Ted , Darquin Alexis , Rasmus John 
Published: December 2007

Abstract
Six horizontal wells were drilled into the Tertiary Chatt Sand reservoir of the Breitbrunn gas field in Bavaria, Germany. The purpose of this campaign was to develop part of the depleted reservoir into a gas storage sand. A detailed geological and petrophysical study was prepared prior to drilling and resulted in the identification of high quality reservoir layers that were targeted by the horizontal wells. Despite the simple anticline structure of the field, geometric drilling was ruled out due to remaining geological and directional uncertainties. The geosteering approach adopted relies on real-time GeoVision Resistivity (GVR·) resistivity images, which were used for the first time ever during this drilling campaign. The image data are compressed downhole and transmitted to the acquisition computer on the rig where they are decompressed and analyzed. The images allow the precise placement of the borehole relative to the geology, which "keeps the bit in the sand". Layer heterogeneity like tight streaks, concretions or patchy porosity can be identified as such, and are not interpreted as a different layer entered by the hole, which would lead to a wrong geosteering decision. Logging-While-Drilling (LWD) azimuthal data are acquired during drilling and also during wash-down passes which follow a bit change. A comparison of these time-lapse data sets can provide invasion profiles through time and around the borehole.