bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on the Damage Induced by Drilling Fluids in Limestone Cores
Authors: Xiao L. , Piatti C. , Giacca D. , Bartosek M. , Nicula S. , Gallino G. 
Published: December 2007

Abstract
Well productivity can be seriously reduced by excessive fluid loss and solids invasion while drilling. If not adequately controlled, losses may push hydrocarbons very far from the hole and solids may plug the pores, increasing the time necessary for testing the well and distorting the evaluation of its productivity potential.
Laboratory procedures for determining the damage of a mud system on rock samples are traditionally based on the return permeability test which provides an indication of both the damaging potential of mud and the efficiency of cleanup techniques.
The non-destructive nuclear magnetic resonance (NMR) measurement is a new methodology for studying the influence of small scale geological heterogeneities on fluid flow and trapping. It permits to check the invasion of solids and filtrate present in the mud using different experimental set-ups. The main advantage is the possibility to have the spatial distribution of the invading phase inside the rock sample. Low frequency (2 MHz) nuclear magnetic resonance relaxation (NMRR) measurements were also used for following the effect of solid mud particulate invasion on the pore size distribution. These techniques provide fast and reliable analysis without the destruction of the sample.
This paper reports the laboratory procedures and the results of a study aimed at determining the damage coming from the penetration of bentonite/mixed metal particle aggregates and polymers into low permeability carbonatic reservoirs. The results were compared with both traditional and innovative methods. Combined with spurt loss, non conventional rheological approaches, dynamic filtration and mud cake SEM (scanning electron microscopy) observations, nuclear magnetic resonance imaging (NMRI) provides precise and directly observable results to distinguish the severity of damage, the type and depth of invasion and, even more, the distribution of invaded particles in the matrix.
The integration of conventional and advanced methods to study damage appears to be highly promising for selecting drilling fluids, with suitable components and particle size distribution appropriate to protect the reservoirs.
Novel High-Pressure/High Temperature Fluid Loss Reducer for Water-Based Formulation
Authors: Audibert A. , Rousseau L. , Kieffer J. 
Published: December 2007

Abstract
Deep drilling require non polluting fluids stable at temperature up to 390 °F. In terms of formation damage, it is now well accepted that prevention is better than remediation since well treatment using washing fluids can be hazardous. This is of major importance for complex well configuration using openhole completion.
Novel polymeric structures were investigated. The additive structure and molecular weight were selected in order to limit the damage due the filtrate invasion. The selected additive was proved to be stable at temperature up to 360 °F. This novel additive was implemented in different water based formulations such as classical bentonite formulation or drill-in fluid and tested in a large range of experimental conditions. The possible damage arising from overbalanced conditions was evaluated in terms of static and dynamic filtration properties, cake permeability, fluid loss characterization and reduction in oil permeability after mud exposure.
Compared to other commercially available fluid loss reducers, it presents better rheological and filtration properties. After ageing at 320°F, no fluid gelation was observed. Under dynamic filtration conditions, the formulation presents a very low filtration rate.
The approach was validated on long core filtration test performed under representative reservoir conditions. Use of a stable additive limits the formation of degradation products that could badly affect the reservoir permeability by plugging effect. Such a design of chemical additive within a water based formulation effectively prevents the well known formation damage arising from the use of water based formulations.
Impact of Synthetic-Based Drilling Fluids on Oilwell Cementing Operations
Authors: Patel Arvind D. , Wilson J. Michael , Loughridge Bill W. 
Published: December 2007

Abstract
This paper presents chemistries of new synthetic-based muds and describes how they affect cement-spacer design. The paper also shows how new fluids and spacers affect the hydraulic bonding of oilwell cements to casings and formations. It discusses the polarity and dispersibility of various synthetic-based fluids and how their chemistry influences cement bonding. Insights into designing new surfactant packages for displacement fluids are provided. Other oil-based fluids are reviewed and compared to the new synthetic fluids. Also presented are new fluid system formulations and other factors affecting drilling performance vs. cementing.
Rising drilling and completion costs, along with an increased awareness of sensitive environmental concerns, have placed more emphasis on effective annular sealing during the primary cement job. Synthetic-based drilling fluids have strong oil-wetting characteristics. Therefore, the following considerations should be made before cement can be successfully pumped behind these fluids: (1) the annular fluid (drilling mud) should be physically displaced by another fluid, and (2) the displacement fluid should leave the casing and formation water-wet. Laboratory experiments testing compatibility and shear bond presented in this paper demonstrate techniques used for cementing behind the new synthetic-based drilling fluids.
Chemical Structures of Group 4 Metal Crosslinkers for Polygalactomannans
Authors: Harry David N. , Putzig Donald E. , Moorhouse Ralph , DelPesco Tom , Jernakoff Peter 
Published: December 2007

Abstract
In SPE 37280 and SPE 39531,* Harry et al., and Moorhouse, et al., respectively, demonstrated that seemingly minor variations in aqueous based crosslinker chemistry can produce significant differences in the rheological responses of polygalactomannan-based fracturing fluids crosslinked with these agents. While the work contained some references to boron crosslinking and the principle conclusion can be applied to both boron and zirconium fracturing fluid systems, the emphasis was on zirconium crosslinked systems. Not surprisingly, some of the observed differences in performance could be attributed to variations in the crosslinker chemistry. Crosslinker differences that were isolated and evaluated included differences in the ligand chemistry, the ligand-to-metal-ratio, the nature of the zirconium starting material, etc. Moorhouse, et al., suggested several mechanisms by which these phenomena might be explained. The authors stopped short, however, of making any attempt to correlate the chemical structure of the crosslinker with its rheological performance.
With this paper the authors advance their studies to present a more comprehensive examination of the proposed structures of titanium and zirconium alkoxides and aqueous-based chelates, including a general discussion of the methods employed to manufacture these crosslinkers and factors present in Group 4 metal crosslinkers that may affect their crosslinking response with polygalactomannans. There is also some discussion on other methods that have been employed to control the gelation rate. Finally, there is some discussion on the effects of polymer attributes to fracturing fluid performance, particularly as it relates to crosslinker efficacy.
The findings presented in the paper are supported by laboratory analyses that includes the examination of crosslinking agents by nuclear magnetic resonance (NMR) imaging, X-ray crystallography, and the rheological performance evaluation of systematically altered crosslinking agents. The authors suggest chemical structures of titanium and zirconium compounds used to crosslink polygalactomannans as supported by the findings of the analytical evaluations already mentioned.
The First Carbonate Field Application of a New Organically Crosslinked Water Shutoff Polymer System
Authors: Hardy Mary , Botermans Wouter , Hamouda Aly , Valdal Jarl , Warren John 
Published: December 2007

Abstract
This paper describes the chemistry and treatment design of the first field application of a recently developed, organically crosslinked polymer (OCP) system for water shutoff. The candidate for which this treatment was designed is a production well in the North Sea that was completed in naturally fractured chalk. Each of the completed intervals were acid fractured to further open the existing natural fractures and increase production.
The recommended treatment volume calculations took into account the leak-off considerations and the acid fracture volume. The method by which the leak-off requirements were calculated is described.
The placement and shut-in temperatures of the recommended treatment volume were then calculated as a function of time. These simulations used a production - operation wellbore simulator in combination with an advanced processes reservoir simulator. The fractures in the target zone were defined in the grid-block system that was used in these temperature simulations.
The results of these temperature calculations were used to formulate the chemical compositions of the stages of the OCP treatment and to calculate gel times and shut-in times. The calculations of these gel times and how they correspond to the gel times during the actual treatment are also described.
Demulsifier Effects on Interfacial Rheological Properties of Asphaltene Films Absorbed at Oil/Water Interface
Authors: Key M S. , Gutierrez S X. 
Published: December 2007

Abstract
The formation of stable water in oil emulsions in crude oil production is caused by the presence of resins and asphaltene which can organize and form rigid films at oil/water interface. In the demulsification process, demulsifier is considered to produce changes in interface rheological properties. This is because demulsification involves displacement of natural surfactants, such as asphaltenes and resins from the film surrounding the water drop. In this research, demulsifier effect and pH variation were evaluated considering the rheological behaviour of crude oil water/interface, and a model system of 1% aphalthene in heptol. Interface viscoelastic properties were studied by a planar rheological method using a surface rheometer at low shearing stress. Results indicate that measurements of creep compliance with pH variation show viscoelastic behaviour for both systems. pH effect on rheological parameters is evident, and elasticity and viscosity notoriously change. Demulsifier effect is noticeable in the different concentration evaluated. Also, it was found that elasticity changes with demulsifier concentration. This is an indicator that demulsifier works to destabilise the interface.
A Comparison of Freshwater- and Seawater-Based Borate-Crosslinked Fracturing Fluids
Authors: Harris Phillip C. , van Batenburg Diederik 
Published: December 2007

Abstract
This paper discusses the chemical factors that operators must address to successfully substitute seawater for fresh water in borate-crosslinked guar fracturing fluids. Seawater contains cations and anions that affect the performance of the fracturing fluid's components, as well as the fluid's interaction with the formation.
Because seawater has high ionic strength, it lowers the viscosity obtained from borate-crosslinked guar. High magnesium in the water consumes hydroxide ions and affects pH control, which in turn affects the equilibrium borate-ion concentration. This paper addresses these problems and provides guidelines for borate fluid formulation to offset seawater characteristics for temperatures as high as 300°F.
Borate fluids from seawater can control fluid loss (FL) as well as freshwater borate fluids. Chemical gel breakers for offshore environments have been developed to help control the viscosity reductions in fracturing fluids. Conductivity values with seawater fluids are equal to or better than freshwater fluids. The presence of divalent cations in the seawater fluid caused no harm to the FL properties or the retained conductivity with borate seawater fluids.
Mathematical Description of Spatial Configuration of Deviated Wells and A New Approach to Calculate Borehole Curvature
Authors: Shi Xingquan , Gong Wei'an 
Published: December 2007

Abstract
This paper firstly describes the spatial trajectory of a deviated well using three-parameter equation, then introduces a new approach to calculate the borehole curvature and torsion based on differential geometry. Finally, the approximation of Lubinski formula is demonstrated. Conclusions from this article can be valuable in guiding the in-situ drilling operation.
P. 279
Drilling and Completion Technique of Paired Horizontal Wells
Authors: Hu Suning , Liao Xuehua , Song Jinshi , Liao Runkang 
Published: December 2007

Abstract
A pair of horizontal wells have been drilled in Du 84 Block of Liaohe oilfield. Their well depths are 1214m and 1189m respectively with vertical depths of 769.81m and 760.51m, horizontal section length of 325.53m and 307.71m respectively. The maximum vertical interval for the two horizontal sections is 11 .98m, and the minimum vertical interval is 1 0.43m. The maximum lateral offset to left is 1 .42m, and the maximum lateral offset to right of 0.47m. Two technical casings are run to the window position in both wells, and horizontal sections are completed by hanging 168mm TBS screen pipes.
P. 393
Application Results and Understanding of Several Problems of Industrial Scale Polymer Flooding in Daqing Oil Field
Authors: Wang Demin , Liu Heng , Niu Jingang , Chen Fuming 
Published: December 2007

Abstract
This paper introduces the scale and production results of six industrial scale polymer flood areas conducted in Daqing oil field, since the large scale application of polymer flooding in 1995. Some important technology problems related to the drawing up of polymer flood development projects will be discussed in greater detail. By discussion of these problems, the following conclusions are obtained: the ultimate production results of polymer flooding are closely related to the injection parameters and injection production methods. In order to get better production results of polymer flooding, optimum injection parameters and suitable injection-production methods must be chosen. ln the meantime, by discussion of these problems, it is shown how to optimize the suitable injection parameters and injection-production methods of polymer flooding when the polymer flooding development project is designed.
P. 477
High Temperature Polymer Flooding in Thick Reservoir in ShuangHe Oilfield
Authors: He Jinsong , Song ZhenYu , Qiu Ling , Xie Feng , Tan ZhongLiang , Yue QingShang , Li XiuNing 
Published: December 2007

Abstract
Shuanghe oilfield is characterized by high temperature, serious heterogeneity and thick reservoir. This paper firstly describes the fine characterization techniques of thick reservoir, including geologic features, microfacies of sedimentation, heterogeneity and hydrodynamic unit analysis, and then introduces the study of thermal-oxidative stability of polymers by adding stabilizers. Finally it summarizes the optimized design and effectiveness of high-temperature (72 C) polymer flooding pilot test in layer II 5, Shuanghe oilfield, where oil recovery is increased by 10.4%.
P. 533
Diagnostic Process Enhances Gas Storage Deliverability–A Case Study
Authors: Blauch Matthew E. , Squire Ken , Guoynes John , Jestes Chad , Loghry Ray , Ford William G. F. , Durey Daniel , Frame Russ , Yater John 
Published: December 2007

Abstract
This paper describes a new diagnostic process that can be applied to gas-storage wells. This technique consists of identifying damage mechanisms and designing individual treatments for each mechanism.
The damage identification portion of the new process involves integrating (1) borehole imaging, (2) downhole sampling, (3) well testing, (4) laboratory analyses, (5) reservoir evaluation, and (6) reviews of well and field histories. This part of the process is partially based on results from a previous formation-damage identification study funded by the Gas Research Institute (GRI).1
Two case studies are provided. Based on overall economic results, field deliverability enhancement projects featuring the new diagnostic process have greater gas deliverability potential than conventionally treated wells. The two case studies presented were performed in porous-media gas-storage fields. Case Study 1 (Page 3) was performed on a pressure-drive carbonate reservoir. Case Study 2 (Page 4) was performed on a water-drive clastic reservoir.
Gas Pipeline Network Analysis Using an Analytical Steady-State Flow Equation
Authors: Zhou Junyang , Adewumi Michael A. 
Published: December 2007

Abstract
Zhou and Adewumi proposed an analytical flow equation (ZA model) for steady-state flow through pipelines without neglecting any terms in the momentum equation. In the present study, the linear theory method (LTM) is utilized to solve the network equations based on the ZA model. Some programming strategies are also addressed. A field network with 21 pipes and 16 nodes is simulated using the model, and the simulation results are compared with the field data as well as those obtained using Weymouth equation, Panhandle-A and Panhandle-B equations, respectively.
Application of Advanced Stimulation Technologies in the Appalachian Basin: Field Case Study of Well Performance Several Years Later
Authors: Fairchild Nelson R. , Williamson Jeron R. 
Published: December 2007

Abstract
From December 1993 through October 1996 the Gas Research Institute (GRI) and several local producers were involved in field case studies which applied Advanced Stimulation Technologies (AST). The objective of the studies was to demonstrate new and emerging technologies that would help the operators optimize hydraulic fracture treatment design, execution, and evaluation. The technologies were demonstrated by applying them to wells (study wells) in the areas of interest. The technologies demonstrated included coring, special logging, pre- and post-fracture welltesting, production data analysis,1 in-situ stress profiling,2,3 3D hydraulic fracture design, real-time fracture diagnostics4, and quality control (QC).5 For each study, a benefits analysis was performed by comparing production from the study wells to offset well production to determine if the application of the technologies was beneficial to the operators. All the studies showed some economic benefit to the operator in the form of increased production, reduced treatment costs, or a combination of both.
Modeling of Well Productivity in Perforated Completions
Authors: Dogulu Y. S. 
Published: December 2007

Abstract
Well productivity is the major factor which determines the economic outcome of a well. It depends on the degree of communication between the wellbore and the producing formation. Most oil and gas wells in the petroleum industry today are completed with a steel casing and cement to control the water influx and production from different zones. In these wells communication with the formation is re-established through perforations, usually created by firing shaped charges. The productivity of the resulting completion depends on design variables like shot density, penetration depth and phasing angle.
Previous attempts to calculate productivity in perforated completions suffer from built-in assumptions that require cylindrical symmetry in the reservoir and equal penetration depths for all perforations. This makes the models difficult to interpret in practical situations and inapplicable to horizontal wells in thin production intervals.
This paper describes an improved numerical model to estimate the productivity of a perforated completion as a function of these perforating parameters. Unequal penetration depth, arbitrary phasing angle and shot density can be specified using a flexible algebraic grid generation technique. The near-wellbore grid is also coupled to a coarse-block reservoir simulator which allows different perforating designs to be exercised depending on the relative location of the wellbore (horizontal or vertical) with respect to the reservoir boundaries.
The model demonstrated a good agreement with the existing models for equal penetration cases. Not a significant difference was observed in the productivity results of unequal penetration cases compared to equal penetration productivity results. Anisotropic runs showed lower productivity ratios compared to the existing models. The near-wellbore productivity model coupled with a reservoir simulator is a very useful tool for designing perforating jobs in thin formations with horizontal and slanted wells.
Enhancing Unconventional Gas Development Economics through Proppant Surface Modification
Authors: Blauch Matthew E. , Morrison William K. , Wilkinson John G. , Minthorn Jim , Terracina John 
Published: December 2007

Abstract
A new proppant-pack technology is enhancing incremental gas recovery and estimated ultimate recovery (EUR) of unconventional methane gas in the Northern Michigan Antrim production area. This new technology has enhanced project economics in both restimulation and new-drill applications. Over time, these new technology applications that have evolved in the Antrim play, have resulted in investment-capital infusion and have encouraged development, which has capitalized on development strategies that implement new technology.
The new proppant-pack technology uses a liquid surface-modification agent (SMA) that is applied to proppant on-the-fly during a hydraulic fracture-stimulation treatment. This process coats individual proppant grains with a "tacky" surface, causing the proppant grains to cluster and create a network of loosely packed grains with interconnected clusters. The result is a pliable, but consolidated, proppant pack. The proppant pack also contains conduits, but its adhesive nature increases proppant resistance to post-fracture migration toward the wellbore. The modified proppant grain surfaces enhance the dewatering process by promoting the flow of aqueous fluids and entrapping potentially damaging fines on grain surfaces rather than in pore constrictions.
This paper compares SMA restimulation technology to newly drilled wells on a project basis. Production enhancement results (based on individual well response and impact on total project production response) show that production results are important at both the project and individual well scale.
When compared to the population of conventionally treated wells, newly drilled completions that received the new SMA technology modified the probability distribution of well production. Restimulation was economical on a payout basis and converted gas-in-place to recoverable reserves, enhancing the economics of lower production-class wells.