bluuebunny/crossref_metadata_2025_split huggingface dataset:
Guidelines for Solving Sand Problems in Water Injection Wells
Authors: Morita Nobuo , Davis Eric , Whitebay Lee 
Published: December 2007

Abstract
Since formation failure and sand production problems in water injection wells are less common than in producing wells, no general guidelines on how to complete water injection wells has appeared in the literature. However, formation failure related sand problems in water injection wells are serious enough that they should be taken into account during the selection of a completion method. This paper provides information on field-observed sand related problems encountered in water injection wells, and discusses the mechanisms leading to sand problems. It reviews the injectivity efficiency of several completion options, and provides guidelines for selecting completion methods for water injection wells drilled through formations prone to sand production. The paper emphasizes that even though sand problems in injection wells are less severe than in producing wells, careful selection and design of completion methods for injection wells can significantly reduce the likelihood and severity of future injectivity problems.
P. 189
Micro-Mechanical Modeling of Perforating Shock Damage
Authors: Swift R.P. , Behrmann L.A. , Halleck P.M. , Krogh K.E. 
Published: December 2007

Abstract
Shaped-charge jet-induced formation damage from perforation treatments hinders productivity. Manifestation of this damage is in the form of grain fragmentation resulting in fines that plug up pore throats along with the breakdown of inter-grain cementation. We use the Smooth Particle Hydrodynamic (SPH) computational method as a way to explicitly model, on a grain-pore scale, the dynamic interactions of grains and grain/pores to calculate the damage resulting from perforation- type stress wave loading. The SPH method is a continuum Lagrangian, meshless approach that features particles. Clusters of particles are used for each grain to provide representation of a grain-pore structure that is similar to x-ray synchrotron microtomography images. Numerous damage models are available to portray fracture and fragmentation. In this paper we present the results of well defined impact loading on a grain-pore structure that illustrate how the heterogeneity affects stress wave behavior and damage evolution. The SPH approach easily accommodates the coupling of multi-materials. Calculations for multi-material conditions with the pore space treated as a void, fluid filled, and clay filled show diverse effects on the stress wave propagation behavior and damage. SPH comparisons made with observed damage from recovered impacted sandstone samples in gas-gun experiments show qualitatively the influence of stress intensity. The modeling approach presented here offers a unique way in concert with experiments to define a better understanding of formation damage resulting from perforation completion treatments.
P. 381
Near-Wellbore Formation Damage by Polyacrylates: Effects of pH and Salinity
Authors: Denys K.F.J. , Zitha P.L.J. , Hensens H.C. , te Nijenhuis K. 
Published: December 2007

Near-wellbore Formation Damage by Polyacrylates: Effects of pH and Salinity
This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper, as presented, have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material, as presented, does not necessarily reflect any position of the Society of Petroleum Engineers, its officers, or members. Papers presented at SPE meetings are subject to publication review by Editorial Committees of the Society of Petroleum Engineers. Electronic reproduction, distribution, or storage of any part of this paper for commercial purposes without the written consent of the Society of Petroleum Engineers is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of where and by whom the paper was presented. Write Librarian, SPE, P.O. Box 833836, Richardson, TX 75083-3836, U.S.A., fax 0l-972-952-9435.

Abstract
Polyacrylates are frequently added to drilling fluids in order to increase viscosity and limit formation damage. In this work we studied the influence of pH and salinity on the bulk flow behaviour and on the permeability reduction caused by polyacrylate retention in a porous medium. Two different retention mechanisms were observed: (non-stationary) core plugging and adsorption. The plugging mechanism could be avoided by adding phosphate to the solution causing a destabilization of polyacrylate aggregates. The permeability reduction in both cases was (strongly) dependent on pH and salinity on the injected water. In the alkaline regime, important for the application in drilling fluids. both the viscosity and the magnitude of the permeability reduction were relatively high. additives.
P. 431
Horizontal Gravel Packing Technique for Slim, Cased Holes in Highly Permeable Zones: A Single Well Case History
Authors: Upchurch E.R. 
Published: December 2007

Abstract
Gravel packing is becoming a common practice for controlling consolidated sands in horizontal wellbores. So far, horizontal gravel packing has been applied almost exclusively to open holes with screens in them, If a formation has a high permeability, and therefore a high fluid loss rate, placement of a gravel pack may be prevented by premature dehydration and bridging of the gravel pack sand in the wellbore/screen annulus, The usual method of preventing these high fluid losses and the resulting bridging is to damage the formation face prior to gravel packing, The damage mechanism is usually salt. calcium carbonate, or other particles that seal off the formation face. Once gravel packing is completed, the formation damage is (hopefully) remediated using acid or undersaturated brines to restore the completion's productivity. There is, however, a risk that the damage cannot be successfully removed once it is gravel packed against the formation face. Acid diversion is also a problem when attempting to remediate damage in an open-hole gravel packed completion.
This paper presents an alternative technique for performing a horizontal gravel pack in a high permeability zone while reducing the risk of permanently damaging the formation's permeability, The technique involves cementing casing through the horizontal completion interval and then shooting perforations in a horizontal orientation. The perforations can then be acidized with better diversion techniques than is possible in an open hole completion. A neutralized screen is then gravel packed. The horizontally positioned perforations provide a self-diverting gravel pack. The self-diverting nature of this technique makes it relatively insensitive to fluid loss; whereas, open hole techniques are very sensitive to fluid loss. The uncentralized liner rests on the bottom of the horizontal to provide maximum standoff from the perforations.
The above technique was applied at Thums Long Beach Company to a well with a 560 horizontal completion cased with a 4#1/2" liner (4.052" ID). The technique's acidizing phase, however. was not performed due to fishing concerns inside the slim liner. This paper presents a case history for gravel packing a 690' long, 2-7/8" slotted liner inside the horizontal 4#1/2" casing. To our knowledge, this is the slimmest horizontal gravel pack ever attempted. The gravel packing was performed successfully even though fluid returns were never established during the job. The lack of fluid returns is due to excessive fluid loss to the formation. The self-diverting nature of the horizontal perforations was the key to successful gravel packing. Production rates, on the other hand. were not as successful since we did not acidize the perforations prior to gravel packing. Comparisons between this well and open-hole horizontal gravel packs are made.
P. 463
Wellbore Cleanup in Horizontal Wells: An Industry Funded Study of Drill-in Fluids and Cleanup Methods
Authors: Burnett David B. 
Published: December 2007

David B. Burnett

Abstract
This paper describes the results of a two year study comparing the performance of a number of commercially available drill-in fluids (DIFs) used in horizontal well completions. The project was designed to provide a direct comparison of those fluids by measuring wellbore and formation damage and well cleanup in horizontal openhole completions in consolidated and unconsolidated formations. Thirteen different types of DIFs were evaluated including laboratory prepared and field samples of sized salt DIFs, synthetic base, polymer-carbonate based, and formate based DIFs. Screening tests were performed in single core (consolidated) tests without sand control screens. Later, radial flow-dynamic leakoff tests were performed in a multi-core test cell. DIFs were also tested in core wellbores modified to evaluate filtercake damage caused by production through sand control well screens.
Practically all DIFs exhibited low spurt loss and good filter loss control. These DIFs formed external filtercakes on the walls of the wellbore, but with little invasion into the rock. A number of cleanup practices were used to remove these filtercakes. HCl acid washes and soaks, dilute brine washes, solvent soaks, and oxidizer treatments were all evaluated. Two types of internal breakers were incorporated into sized salt systems as well.
We found that cleanup was not as effective as expected. Core materials exhibited low regained productivity (permeability) even after cleanup to remove wellbore damage. Low regained permeability was related to the nature of the DIF filtercakes and to the presence of simulated drill solids added to the DIFs. These materials caused the filtercakes to be tighter, more tenacious and harder to remove from the wellbore. Production of filtercake and filtercake residue from well walls also caused significant screen plugging. Polymer- carbonate DIFs showed greater screen damage than sized salt systems.
As we learned more about the causes of damage we modified our completion practices to incorporate new DIF formulations and new cleanup practices. As a result the average productivity regained went from 58% regained flow capacity in the first year of testing to 71% in the final year of the program.
P. 469
Fines Migration Control in High-Water-Cut Nigerian Oil Wells: Problems and Solutions
Authors: Ezeukwu Toni , Thomas R.L. , Gunneroed Terje 
Published: December 2007

Abstract
Although fines migration has been investigated in the laboratory and the field for more than 30 years, severe loss of production resulting from fines migration still exists in countless reservoirs. This field study evaluated organic and inorganic clay-control agents to determine their effectiveness to eliminate fines (silt and clay) migration in high production-rate wells. Four gravel- packed wells that exhibited severe fines migration problems subsequent to conventional hydrofluoric acid (HF) treatments were over flushed with an organic polymeric clay-control agent. The wells were acidized again after production had significantly decreased because of fines migration and over flushed with an inorganic agent to compare their performance Descriptions of the candidate selection and design procedures are provided with the chemistry of the clay-control systems and their control mechanism.
This paper supports previous laboratory results that found organic polymeric clay-control agents are not effective in eliminating fines migration owing to mechanical dislodgment. In most cases, production declined 50 to 90% within one year following organic clay-control treatments. Additionally, the onset of water production further increased the production decline rate because of increased fines migration. Following the inorganic clay-control treatments, fines migration was greatly decreased although the wells were producing at higher rates with higher water-cuts. The oil production one year after the modified treatments was more than double the production at one year following the organic clay-control treatments. Five to six years after the inorganic fines-control treatment production was equal or higher than the one year rate following the organic clay-control treatments.
P. 529
Mud Filtrate Invasion Profile - Its Influence on Wireline Logs and Hydrocarbon
Authors: Borah N.M. , Mallick R.K. , Choudhuri B. , Rathore Y.S. 
Published: December 2007

Abstract
Invasion of mud filtrate into permeable formations impedes accurate formation evaluation and impairs productibility of oil and gas reservoirs. The paper describes a case study to demonstrate the time lapse effect of invasion on wireline log response and its effect on hydrocarbon productibility.
P. 119
Production Optimization in Mature Fields Using Technology Integration of Production Logging, Horizontal-Well Technology and Water-Shutoff Techniques
Authors: Habib El Sayed , Osman Magdy S. 
Published: December 2007

Abstract
Water production started increasing from some Bapetco's oil/gas reservoirs with a subsequent drop in hydrocarbon production. Water movement in the reservoir was not well understood, and it was not clear whether zones of high hydrocarbon saturation still existed. Therefore, a saturation distribution study was initiated with the objective of increasing oil/gas production while decreasing water production. The geology of the fields was examined to select key wells for determining the water saturation using thermal neutron decay time logs. In wells with existing TDT* logs, the time-lapse technique was used to determine the change in saturation. In wells without existing TDT logs, the open hole saturation just after drilling was used to determine the change in saturation. The saturation changes were incorporated with the field geology to provide a good understanding of saturation over the entire reservoir. The integration of production log results, production geology and simulation data has led to a new picture. Water shut off using through-tubing bridge plugs was applied as a solution for the increasing water production. Other water shut off techniques were also considered. Unflushed zones were perforated to increase oil production. Using an updated simulation model, horizontal wells were planned to target unswept zones. One horizontal well was drilled so far with good result. The paper presents the successful integration of at least four different techniques in order to optimize reservoir performance.
The Role of Reservoir Management in Carbonate Waterfloods
Authors: Thakur G. C. 
Published: December 2007

Abstract
The need to enhance recovery from the vast amount of remaining oil- and gas-in-place in the carbonate reservoirs requires better reservoir management practices. Proper timing has a profound effect on the implementation of sound reservoir management technology on recovery efficiency. With this in mind, our goal should be to maximize volumetric sweep early in the project's life. Trying to squeeze more oil from marginal projects will generally yield marginal to average results. The purpose of this paper is to: (i) identify the major attributes of a successful waterflood asset management program, (ii) outline critical issues and technical areas, and (iii) document benefits received from a team approach to asset management, utilizing carbonate reservoir case studies.
Nitrogen Containing Organic Compounds as Corrosion Inhibitors of Mild Steel Corrosion in Oilfield Acids
Authors: Kumar T. , Vishwanatham S. , Emranuzzaman _ , Talukdar B. N. 
Published: December 2007

Abstract
The paper describes results of a preliminary laboratory study on corrosion protection of mild steel in 15% HCl and 3% HF used in acidization of oilwell by some N-containing organic compounds. Inhibition efficiencies were evaluated by metal loss and potentiostatic polarisation methods. The corrosion rate of mild steel decreased appreciably even in the presence of traces of the compounds. The extent of decrease in the corrosion rate was found to depend on the nature of the inhibitor and its concentration. Results of testing the additives in preventing corrosion of mild steel by the acid solution at different temperatures (30 to70°C) and exposure times (6h to 36h) at a fixed inhibitor concentration are also reported here. Thermodynamic parameters like heat of adsorption and activation energies have been calculated in the absence and presence of these organic additives. The nature of the film formed on the metal surface was analysed by infrared (IR) spectrum and relationship between structure of the organic compounds and inhibition effeciency has been explained.
Internal Corrosion Failure Model of Compressed Natural Gas Transmission Lines and Efficient Mitigation Programme
Authors: Saxena A. K. , Sharma V. K. , Chugh S. K. , Velchamy S. , Kumar Ramesh , Prakash Ram , Sharma B. K. , Dinesh R. S. 
Published: December 2007

Abstract
Corrosion aspects of oil field production facility continues to receive ever-growing attention because of increasing cost of energy and need for safe and reliable operations so critical for overall profitability. Failure of compressed natural gas transmission line, between Sanand and Jhalora oilfields is wide spread due to suspected internal corrosion and often required replacement. Intensive efforts have been made to study character of the problem. The investigations include an analysis of the internal environment of the pipeline and failure analysis of a failed pipeline sample including visual inspection, ultrasonic measurements, metallographic investigation, material property testing like hardness and tensile strength and gravimetric corrosion rate studies under simulated line conditions.
Significant high partial pressure of CO2 and presence of water induce internal corrosion which is accelerated due to erosional affect of annular mist flow inside the line. The synergistic effect of erosion-corrosion leads to execessive localized pitting and thinning of wall of transmission line leading to ruptures.
Continuous low dose addition of an oil soluble water dispersible amine inhibitor is found to be technically most feasible aspect to avoid system failure in future. The inhibitor had good film forming and film maintenance properties. The need to atomise the inhibitor to obtain suitable transport characteristics is emphasized.
Modeling Fluid Flow in Complex Naturally Fractured Reservoirs
Authors: Kamath J. , Lee S. H. , Jensen C. L. , Narr W. , Wu H. 
Published: December 2007

Abstract
We use a new numerical code to calculate single phase fluid flow in naturally fractured reservoirs. Our code is unique in that it can handle both complex fracture patterns and the coupling of the matrix and fracture flow fields. Our results show that details of the fracture statistics can become less important as the matrix becomes more permeable. We also find that the coupling of the matrix and fracture flow fields is very strong. We demonstrate the application of our code to develop grid block permeability values for use in continuum reservoir simulators.
Mapping subsurface fracture distributions for use in our code is a key challenge. We briefly present the results of a new methodology that uses physical models and geostatistical techniques to generate such data.
A New IPR's Establishment and Solution for Horizontal Wells
Authors: Huang Bingguang , Liu Shuzhi , Li Shunchu , Li Lianwu , Zhang Xinglin , Chen Zhengsheng 
Published: December 2007

Abstract
Many researchers find that when IPRs of a vertical well are used in a horizontal well, the results are not satisfactory. To be exact, the exponent type of IPR can not reasonably match the late part of the observed curve, while the binomial equation can not match the early stage of the curve very well. Bendakhlia et al1 combined the two equations into an equation, and applied it to describe the IPR of a horizontal well. They thought that the composite equation can better be used in a horizontal well, and verified the conclusion by means of numerical simulation results. However, the equation is only valid to an ideal well (a well without any negative or positive skin factor).
Considering Bendakhlia's work, the authors introduce a flowing efficiency R to establish a new IPR for horizontal wells so as to broaden its application. The new equation is suitable to both ideal wells and actual wells (damaged or stimulated wells). Moreover, this paper presents the solution technique to obtain unknown parameters in the formula for dimensionless IPR curves of a horizontal well according to steady well testing data. Several examples have shown that the new IPR equation can give satisfactory performance prediction results of horizontal wells. Its prediction accuracy is higher than that of the IPR developed by Bendakhlia et al. The relative errors of oil flow rates in an example are within 1.5%.
Do Fluid Loss Control Additives Perform As Claimed In Acid-Fracturing Treatments
Authors: Mumallah Naim A. 
Published: December 2007

Abstract
Acid is injected into an induced fracture to etch the walls and make passageways that remain open after an acid fracturing treatment for the reservoir fluids to travel to the well bore. Unfortunately, a substantial portion of the acid leaks off into the matrix surrounding the fracture. Acid leaks off through natural fractures or through the walls by forming wormholelike passageways into the matrix. To minimize acid leakoff fluid loss control additives are routinely incorporated in treatment pads. Which additive and how much to use for a given reservoir are always chosen arbitrarily.
This paper reports on a study of some variables that may affect acid leakoff through wormholes. The paper also presents results of an evaluation of the effectiveness of fluid loss control additives in acid-fracturing treatments. An apparatus was built that permitted the investigation of acid leakoff under dynamic flow conditions similar to what occurs from the fracture in acid fracturing treatments.
The results indicated that acid reacts uniformly and worm holes do not develop or propagate through chalks, regardless of the pressure difference between the fracture and the matrix surrounding it, if the calcite content of the chalk is less than 70%, and/or the effective permeability is less than 0.035 mD. The results also revealed that fluid loss control additives did not affect acid leakoff through worm holes; regardless of whether the additive was incorporated in the acid pad, in the viscous pad or in both.
Based on the results of the laboratory study acid-fracturing treatments were performed in the field with pads that did not contain fluid loss control additives. The results of field treatments confirmed the laboratory findings when wells stimulated with pads that did not include fluid loss control additives performed comparably to wells acid-fractured with pads that contained additives.
P. 575