bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved Resistivity Interpretation Utilizing a New Array Laterolog Tool and Associated Inversion Processing
Authors: Smits J. W. , Dubourg I. , Lüling M. G. , Minerbo G. N. , Koelman J. M. V. A. , Hoffman L. J. B. , Lomas A. T. , Oosten R. K. v. d. , Schiet M. J. , Dennis R. N. 
Published: December 2007

AbstractIn many situations the traditional dual laterolog does not supply sufficient information in thinly bedded formations to unambiguously determine true formation resistivity (Rt). In addition, the laterolog-deep measurement may be affected by the presence of highly resistive layers, especially when logging close to the casing (Groningen effect) or when the tool is conveyed on drillpipe. These limitations of the traditional dual laterolog measurement can lead to sub-optimal development decisions and even to missed production opportunities.A recent array laterolog tool, combined with inversion processing, provides answers to these issues. The tool makes several focused measurements with different depths of investigation, in concept similar to an array induction tool. The hardware is optimized to supply maximal measurement-information. The data is interpreted by inversion software using formation models of varying complexities to best approximate the true formation resistivity. All measurements use bucking currents returning to the tool rather than to surface, effectively eliminating the Groningen and drillpipe effects.At the wellsite, Rt is provided by a fast one-dimensional (1D) inversion that takes into account only radial resistivity variations and is strictly applicable only in thick beds. The input-curve reconstruction identified inconsistencies between this simplified model and the true formation that would go unnoticed when inverting conventional dual laterolog data. A typical example is the proximity effect of a cap rock in a horizontal well, which produces curve separation that is qualitatively distinct from the separation caused by invasion.In thinly bedded formations, inverting a two-dimensional (2D) axisymmetric formation model improves the interpretation by simultaneously accounting for radial and vertical resistivity variations. The inversion can handle complex invasion profiles and produces a 2D image of the formation resistivity.These methods were applied to surveys of a number of wells drilled in clastic formations, ranging from vertical to highly deviated and horizontal. Comparison with tools operating according to the dual laterolog principle clearly showed the benefit of this new technology. Interpretation improvements were obtained mainly from the increased information content of the array signals. Also, the absence of artifacts associated with distant current returns (such as Groningen-type effects) improved the saturation evaluation.
Solvent-Acid Dispersions Solve Difficult Stimulation And Clean-Up Problems
Authors: Coffey M.D. , Thompson J.L. , Carney M.J. 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.
This paper was prepared for the Rocky Mountain Regional Meeting of the Society of Petroleum Engineers of AIME, to be held in Billings, Montana, May 15–17, 1974. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is granted upon request to the Editor of the PETROLEUM ENGINEERS JOURNAL is granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the SPE magazines.

Abstract
Acid stimulation or clean-up treatments of producing and injection wells are often complicated producing and injection wells are often complicated by hydrocarbons which prevent intimate contact between acid and acid-soluble materials. The use of hydrocarbon solvent-in-acid dispersions to simultaneously dissolve both the hydrocarbon and acid soluble deposits has proved highly effective. This allows one-stage cleanup of hydrocarbon coated formations and avoids costly multi-stage treatments.

Introduction
The production of oil and gas wells is often seriously hindered by the presence of hydrocarbon and inorganic scale deposits in the tubing, the wellbore, formations and downhole equipment. Only acid soluble inorganic scale will be discussed in this paper. These accumulations of hydrocarbons and inorganic scale cause a gradual decline in production which is often mistaken for the natural production which is often mistaken for the natural decline of a well. These same deposits also lower the injection rates of water injection wells. To obtain full production or injectivity capacity it is often necessary to remove the deposits.
Hydrocarbon removal techniques are numerous and may be divided into three categories:Mechanical — scrapers and abrasivesChemical — solvents and surfactantsThermal — hot oil and heaters
All of these categories have been used commercially. Numerous paraffin inhibitors have also been used to help control the problem. Only the chemical removal techniques will remove an appreciable amount of hydrocarbons from within the rock matrix. Solvent removal differs from surfactant removal in that the solvents dissolve hydrocarbons while surfactants only disperse hydrocarbon deposits.
The Design and Early Performance History of Two Waterflood Pilots in the Mauddud Carbonate Reservoir, North Kuwait
Authors: Al-Anzi Ealian , Mousawi Ahmed , Malik Satinder , Blackburn Neal , Reddick Chris , Rothwell Nigel , Young Perry , Haynes Byron 
Published: December 2007

Abstract
The Mauddud formation is a major oil bearing carbonate reservoir in North Kuwait. Historical Production (spanning over 40 years) has confirmed that the reservoir receives very little natural pressure support. This has resulted in a declining reservoir pressure and low recovery factor. The forward development plan is to waterflood the Mauddud, increasing production rate and ultimate recovery. An assessment of the reservoir suggests that a pattern waterflood will be required to achieve the aggressive production profile while meeting targets for increased, ultimate reserve recovery.
The waterflood pilot project (WFP) was planned to gather actual field data on waterflood performance in representative areas of the reservoir. A thorough screening of the available reservoir data was conducted in order to select suitable locations for the pilots. A limited area 3D seismic survey was shot over these locations to further check that no major reservoir anomalies were present in the planned pilot areas.
Two inverted five spot pattern waterfloods were planned and constructed, one in each of the Raudhatain and Sabriyah fields. Production wells were completed with artificial (gaslift) lift capability to allow continued production as watercuts increased. A novel twin ESP source water system was constructed to take water from a deep aquifer source and pump this into the injection well at the necessary rate and pressure. A comprehensive data acquisition programme during the well construction and commissioning phase of the project allowed the essential base reservoir data to be acquired.
A multiwell interference/Pulse test was conducted in both pilot areas prior to the start-of full production/injection, this confirmed good connectivity within the pilot areas.
Full pilot operation commenced in June 97, with first water breakthrough (in some of the production wells) being observed 2–3 months after start-up. this was within the range of earlier predictions
The pilot waterflood has already given a valuable insight into the performance of the Mauddud under waterflood conditions and the pilot results indicate the Mauddud can be successfully developed by adopting a pattern waterflood approach. Injectivity and productivity have been better than expected and the implications for sweep efficiency /directionality and reserve recovery look encouraging.
The Effect of Cloud Point Temperature on Wax Deposition
Authors: Sadeghazad Ayoub , Christiansen Richard L. 
Published: December 2007

Abstract
The main object of this paper is to evaluate and discuss wax deposition problem. It can vary from minor to extremely sever depending on the cloud point temperature, the operating temperature, and the wax content of crude oil. On the other hand, cloud point temperature is related to the solution apparent molecular weight. In other words, cloud point temperature is a function of solute and solvent apparent molecular weights and their mole fractions.
Two sets of experiments were performed to analyze the effect of cloud point temperature on wax deposition. The first was solute mole fraction (weight fraction) dependence and the second was solvent dependence experiments. The results indicate that as the apparent molecular weight of solution decreases, the cloud point temperature decreases. So, the lower cloud point temperature, the later precipitation and deposition of wax.
As the apparent molecular weight of solute and its mole fraction decreases, the cloud point temperature decreases. Moreover, as the mole fraction of the solvent increases and its apparent molecular weight decreases, the cloud point temperature decreases.
Litho-Facies and Permeability Prediction from Electrical Logs using Fuzzy Logic
Authors: Cuddy S. J. , Putnam T. W. 
Published: December 2007

Abstract
Several areas of the geosciences have benefitted from the application of the new mathematics of "fuzzy logic" (Nordlund1; Cuddy2). BP routinely uses new interpretation techniques, based on fuzzy logic, to predict permeability and litho-facies in uncored wells. Litho-facies and permeability prediction have presented a challenge to formation evaluation due to the lack of tools that measure them directly.
Fuzzy logic is simply an application of recognised statistical techniques. Whereas conventional techniques deal with absolutes, the new methods carry the inherent error term through the calculation rather than ignoring or minimising it. This retains the information associated with the error and gives surprisingly better results.
One clear application is to litho-facies determination. Litho-facies typing is used in well correlation and is important for building a 3D model of the field. The technique makes no assumptions and retains the possibility that a particular litho-facies type can give any log reading although some are more likely than others. This error or fuzziness has been measured and used to improve the litho-facies prediction in several North Sea and Middle East fields. In one study, descriptions from 10 cored wells were used to derive litho-facies descriptions in 30 uncored wells. This technique gave near perfect differentiation between aeolian. fluvial and sabkha rock types. In addition, it went some way towards differentiating between sandy, mixed and muddy sabkhas. Using the fuzzy logic technique gives better predictions than more complicated methods.
A second application is permeability prediction. Knowledge of permeability is important in determining the well completion strategy and resulting productivity. The problem with permeability prediction is derived from the fact that permeability is related more to the aperture of pore throats rather than pore size, which logging tools find difficult to measure. Determining permeability from logs is further complicated by the problem of scale; logs having a vertical resolution of typically 2 feet compared to the 2 inches of core plugs. The new techniques quantify these errors and use them, together with the measurement, to improve the prediction. This new approach has been used in several fields around the world to obtain better estimates of permeability compared to conventional techniques. In addition, the method relies on basic log data sets such as gamma-ray and porosity rather than depending on new logging technology.
New Classification of Carbonate Rocks for Reservoir Characterization
Authors: Marzouk I. , Takezaki H. , Suzuki M. 
Published: December 2007

ABSTRACT
Several classifications of carbonate rocks are known to the oil industry. The most recent one is the Dunham Classification, 1962, more than 33 years ago. In these classifications, several descriptive names were used to identify different types of Limestones which have created a lot of confusion specially for non-geologists. Rock typing is one of the main challenges in reservoir characterization. Defining porosity and permeability finger prints for each rock type is a subject of increasing interest in reservoir geology. This will help defining permeability distribution, better understanding of fluid flow behavior which will lead to more realistic • production forecast. Unfortunately, previous classifications of carbonate rocks are not enough to satisfy this objective since conventional rock types have wide range of porosity and permeability. Detailed core description and petrographic studies on the Thamama and Arab Carbonate reservoirs of Abu Dhabi have significantly contributed to the internal architecture, the building blocks and other parameters used in carbonate rock classification. Scanning Electron Microscope, Nuclear Magnetic Resonance and Mercury Injection Capillary Pressure were used to differentiate between the different rock types. The main objective of this work is to find out a practical classification of carbonate rocks to be used in reservoir characterization and to match with the petrophysical and dynamic data. The building blocks of carbonate rocks used in this study are the micrite crystals, the micrite particles and the carbonate grains. The Micrite particle is a new component introduced by the authors to the building blocks of carbonate rocks. It represents an aggregate of micrite crystals ranging in size between 10–20 microns which create inter-particle porosity of approximately 4 microns. This new finding has explained the major deflection on the Ø/K cross plots of the Thamama reservoirs of Abu Dhabi.
The new classification proposed in this work is mainly based on pore throat size distribution. The other components used in this classification are the micrite particles, grain/micrite ratio and core porosity and permeability. The proposed classification has explained several unique cases related to mis-matching among descriptive rock types, measured petrophysical data and dynamic data. Significant variation in permeability at constant porosity and the changing capillary pressure and relative permeability behavior for one and the same rock type are good examples.
A Micromodel Study of Acidization Foam
Authors: George D. S. , Islam M. R. 
Published: December 2007

Abstract
The generation of foam in porous media is believed to be through a series of snap-off and bubble/lamella processes. Even though this hypothesis explains the generation of foam in porous media, the propagation of foam through the same series of phenomena is not properly explained. In an effort to develop a theory, generation and propagation of foam in porous media were visualized in a micromodel. The generation and transport of foam were observed as a function of pressure, flow rate, the presence of acid, the presence of oil, and surfactant concentration. It was found that for most cases the generation process itself is chaotic. However, a narrow band of parameters was detected for which periodic and even quasi-periodic behaviour was observed. Interestingly, the range of periodic and quasi-periodic behaviour was broader in the presence of acid. The presence of oil led to easier attainment of the chaotic state.
The role of geometry was found to be important. For instance, periodic behaviour was observed more easily in the pore neck as compared to the pore body. Flow rate and pressure both enhanced the chaotic state and narrowed the band of the existence of the periodic and quasi-periodic state. The existence of quasi-periodic behaviour in multiphase systems has rarely been identified in the past. The relevance of these so-called theoretical states to the petroleum engineering aspect is discussed in the paper. It is shown that these observations lead to valuable clues for the design of a foam diversion process.
Formation Damage and Near Wellbore Flow in Reservoirs – An Experimental Study
Authors: Al-Marhoon N. O. , Grattoni C. A. , Dawe R. A. , Carter J. N. 
Published: December 2007

Abstract
The most important region of a producing reservoir is the zone within 5 meters of a wellbore. All fluids have to flow through it, usually at high flow rates compared to that in the deep reservoir away from the wellbore. Exactly how and what route the fluids flow to the perforations and hence into the wellbore is not well understood. The near wellbore formation permeability significantly affects pressure profiles and hence well deliverability and production rates. This near wellbore area is usually damaged in that its averaged permeability is less than the average of the reservoir; such effects are often termed ‘skin effects’.
This paper aims to improve our understanding of near wellbore flow by experimental demonstration of the differences in flow and displacement behaviour between heterogeneous and homogeneous porous media. The heterogeneities under investigation are permeability and wettability contrasts. We believe that the differences are very significant and their neglect in the past has led to the many reported (and unreported) failures in well-bore stimulation, and which have proved very costly. In our experiments we have used visual models packed with Ballotini glass beads. The permeability/wettability contrasts were carefully controlled and tested. The experiments provide visual evidence of the flow patterns occurring within such heterogeneous porous media in the vicinity of the wellbore. Pressure distributions around this heterogeneous area show where the flow restrictions are likely to occur.
If the understanding of the near wellbore flow can be incorporated into simulation, then the accuracy of the reservoir simulation and the characterisation of the reservoir itself should be improved. This may provide a reduced range of uncertainty when interpreting history matches, well tests and well logs. Also a better appreciation of near wellbore flow patterns before well clean-up should improve the reliability of the chemical placements.
Static and Dynamic Reservoir Rock Compressibility at High Pressure
Authors: Macini Paolo , Mesini Ezio 
Published: December 2007

Abstract
The paper reports measurements of rock compressibility performed by means of an equipment capable to operate up to 150 MPa confining pressure. Measurements have been performed on 32 samples from 3 sandstone and 3 carbonatic reservoirs. The experimental apparatus was designed to perform both static investigations (deformation tests, to calculate bulk and pore compressibilities) and dynamic investigations (acoustic tests, for the evaluation of undrained compressibility). Results show that compressibility is not constant, but is a function of reservoir pressure. In particular, compressibility of sandstones follows an exponential trend, decreasing rapidly in the first part of the loading cycle, and remaining almost constant at high pressure. Compressibility of carbonatic samples shows the same behaviour, but increases for stresses close to the yield point. The attempt to correlate dynamic and static tests reveals the necessity of additional investigations; in fact, it has been noticed that undrained compressibility measured by dynamic tests yields inconsistent results for non-elastic rocks, and, generally, dynamic measurements do not correspond to the static ones.
Organizational Learning and Management of Change
Authors: Khoori Ahmed 
Published: December 2007

Abstract
This paper introduces the theory of a learning organization and management of change followed by their practical applications in the Abu Dhabi Company for Onshore Oil Operations(ADCO).
The paper highlights the meaning of a learning organization and the management of such organization together with the measurement criteria necessary to measure progress. It also explores why some change initiatives have failed to provide the necessary results.
Furthermore, distinctive policies and practices that are responsible for the success of learning organizations and the forming of the five building blocks of a learning organization, namely systematic problem solving, experimentation with new approaches, learning from their own experiences and best practices of others in addition to dissemination of knowledge, is introduced.
Rock Type and Permeability Prediction from Mercury Injection Data: Application to a Heterogeneous Carbonate Oil Reservoir, Offshore Abu Dhabi (United Arab Emirates)
Authors: Al-Aruri Ahmad , Ali F. Baba , Ahmad Habib A. , Samad Saleh A. 
Published: December 2007

Abstract
Present study highlights reservoir engineering contribution to a reservoir characterization study.
Subject reservoir is a heterogeneous limestone and dolomite carbonate reservoir, with a huge gas cap, producing under peripheral water injection.
Available conventional and SCAL data were screened, filtered and introduced in spreadsheets.
Measured permeability and porosity values were corrected to reservoir conditions in order to bring all relevant data to the same conditions.
The main objective of analyzing Mercury Injection Capillary Pressure (MICP) data was to come up with conceptual reservoir flow-model from integrating the rock fabrics of the depositional facies with the MICP measurements.
Distinguishing dolomite from limestone plugs was the first step taken in the rock typing exercise based on petrography findings. MICP curves were sorted based on various criteria to come up with 16 rock types using Excel 7.0 spreadsheets equipped with macro facility to speed up analysis. Water saturation versus pore throat distribution and R35 ( Inverse of capillary pressure at 35% mercury saturation) parameters were found to be the most useful tools in this exercise.
Second campaign of mercury injection data (99 samples) was carried out in order to capture more samples in low populated rocks. This brings total mercury injection samples to 568 taken from 15 wells, in which around 50% were dolomite.
The 16-rock-model has been successfully correlated to distinctive flow units (such as FZI: Flow Zone Index and RQI: Reservoir Quality Index) and in light of the results it was possible to upscale the 16-rock-type model into 9-rock-type model. The 9 rock types consist of 4 dolomite rock types and 5 limestone rock types.
A stochastic model has been developed and applied successfully on cored wells, using Random Number Generator function in Excel 7.0, to predict rock number (type) at a given porosity and permeability for every foot.
Capillary pressure end points were used to predict water saturation and comparison against water saturations from logs revealed a good relationship.