bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanisms of Downhole Sand Cavity Re-Stabilisation in Weakly Consolidated Sandstones
Authors: van den Hoek P. J. , Kooijman A. P. , De Bree Ph. , Kenter C. J. , Sellmeyer H. J. , Willson S. M. 
Published: December 2007

Abstract
This paper presents a theoretical and experimental investigation into the possibility of cavity re-stabilisation after initial sand failure by formation of stable wormholes (‘pipes’) behind the casing / liner. Piping has been observed in dikes in The Netherlands.
A model has been developed to compute the degree of cavity re-stabilisation and associated sand production rates. The theoretical results show that formation of wormholes can result in re-stabilisation and associated reduction in sand production. The theoretical work has been verified by laboratory sand production experiments. Experiments on friable sandstones show that formation of wormholes can take place as part of a re-stabilisation process. Experiments in homogeneous unconsolidated sandstones, on the other hand, show that under elevated stresses, it is impossible to form stable wormholes in this case. Experience with dikes however show that wormholes in these sands can occur when they are interbedded with shales/clays.
The results above in homogeneous sandstone are further supported by tests with horizontal pre-drilled, uncemented liners in weakly consolidated artificial sandstones. Formation of stable sand arches over the liner holes takes place at low values of far-field stress. However, elevated values of far-field stress lead to a continuous, high-rate (‘massive’) sand production.
Specifying Lengths of Horizontal Wells in Fractured Reservoirs
Authors: Stowell Julia F. W. 
Published: December 2007

Abstract
When drilling a horizontal well in a fractured reservoir the aim is to intersect those fractures that are capable of providing a conduit for fluid flow. Key factors influencing the success of a horizontal well include the choice of horizon and the direction of drilling. However, even if these have been determined, the drilling distance required to achieve the aim remains a problem.
New methods have been developed which allow an appropriate drilling distance to be constrained on a site-specific basis, where opening mode fractures are dominant. These methods utilize knowledge gained through empirical studies of the scaling properties of fracture populations. Statistical constraints on the required well length are calculated through measurement of the aperture size distribution of the fracture population, combined with observation of the history of fracture fill. Calculations of fracture permeability are made, based on the scale of data acquisition and are compared with matrix permeability.
A case study of opening-mode fractures in the Austin Chalk reveals that large, potentially open, fractures are commonly clustered, the distance between clusters ranging from ~1m to ~50m. Aperture size distributions follow power laws and spacing size distributions are negative logarithmic or lognormal. The aperture size at which fractures are open to fluids is variable (0.14-11mm). Fracture permeability is dependant on the scale at which it is measured and has been determined at 7.1D (for 18m of Lower Austin Chalk core) and 286D (for 300m of Upper Austin Chalk outcrop). These calculated fracture permeabilities are several orders of magnitude larger than the typical Austin Chalk matrix permeability of 0.03-1.27mD.
The Role of Open Hole Memory Logging and Wireless Conveyance Systems in the Evaluation of Horizontal Wells
Authors: Elkington Peter A S 
Published: December 2007

Abstract
Open hole formation evaluation logs are not run where the perceived benefits are marginal. In many horizontal wells, the benefits are not fully assessed because cost and/or access difficulties override other considerations. In these cases, sub-seismic lateral variations in reservoir properties can only be inferred - they are rarely measured. Small diameter battery-powered logging tools operating without a wireline have collected high quality data in a broad range of high angle situations. Wireless conveyance techniques are faster and safer than wireline pipe conveyed logging, and have cost, access and data quality benefits over logging while drilling (LWD). Wireless tools have been conveyed in and on drill pipe, on coiled tubing without an electric line, and as part of a modified casing string. The tools can be deployed safely in underbalanced wells.
How Can Horizontal Wells Help in Naturally Fractured Reservoir Characterization?
Authors: Mazouzi A. , Deghmoum A. , Azzouguen A. , Oudjida A. 
Published: December 2007

Abstract
Information obtained from testing horizontal wells is very useful in reservoir characterization, in this paper the experience of horizontal wells in the gas reservoir of TIN FOUYE TABANKORT (TFT), Algeria is illustrated, as well as the contribution in characterizing natural fractures.
The transient response (Build Up) of two horizontal wells were simulated, the two short radii TFT#z329 (400m), and TFTz#333 (200m) were drilled in the same azimuth the numerical match yields to the following permeability tensors: well TFTz#329 (Kx = 2 md, Ky = 90 md, and Kz = 110md), and well TFTz#333 (Kx = 5 md, Ky = 100 md, and Kz = 115 md).
The permeability tensors obtained correspond to a configuration indicating a plan of oriented fractures. The wells have been drilled perpendicular to the fractures. The matrix permeability is K matrix = 5 md and the fractures permeability K fissures = 100 md . these results were confirmed by the imagery (FMI, ARI) run in both wells. Laboratory tests on cores of vertical wells confirmed these results and gave the fractures permeability K fractures = 70 md.
Using Horizontal Gravel-Packing Technology to Optimize Well Productivity and Field Economics: Case History, Uracoa Field, Venezuela
Authors: Benavides Simon P. , McKee John Paul 
Published: December 2007

Abstract
This paper summarizes the evaluation and effects of completion alternatives on the productivity and economics concerning the redevelopment of the Uracoa field in Southern Monagas, Venezuela. It explains how horizontal gravel pack technology restored well productivity and improved longevity. Production from the Uracoa Field consists of heavy crude ranging from 11° to 16° API. The initial redevelopment completion scenario used horizontal wells with slotted liners in open hole. However, subsequent breakthrough of water caused catastrophic sand production that plugged the wells where slotted liners were implemented. In order to produce the Uracoa Field economically, it was necessary to perform a technical evaluation of in-field completion and drilling practices to resolve production issues for sand control, high CO2 production, 13-14% asphaltene content, well productivity, and well longevity.
After evaluating completion and drilling practices, horizontal gravel packing technology was used to restore well productivity and longevity. In order to achieve optimum productivity, it was necessary to do extensive fluids compatibility testing to determine the overall best drilling and completion practices. To date, over 65 horizontal wells have been gravel packed in conjunction with a large number of highly deviated wells. These gravel packs make use of water-packing techniques and maintain higher productivity even after water breakthrough.
The paper reviews completion and well experience with slotted liners, evaluates completion practices, and compares completion technologies implemented in the Uracoa Field to achieve economic productivity. Finally, data presented demonstrates the ability to maintain productivity even after water breakthrough.
Multilateral Pressure-Transient Response
Authors: Yildiz Turhan 
Published: December 2007

Abstract
This study presents a 3D analytical model to analyze the transient flow into multilateral horizontal wells. The model considers arbitrary phasing angle, selective lateral completion, non-uniform formation damage around each lateral, and areal and vertical permeability anisotropy. Using the model, transient pressure, derivative, and rate distribution characteristics of multilateral horizontal wells are investigated. Flow regimes are examined. Asymptotic approximations for each flow regime and pseudoskin equation are provided.
A sensitivity study is carried out to identify the parameters controlling the transient pressure, derivative, and fractional rate responses. The sensitivity study includes the impact of lateral length, orientation, and number, formation anisotropy, and the degree of formation damage around the laterals. If all the laterals are put on production during the test, it is almost impossible to estimate principal permeabilities, their directions, and skin factors around each lateral by examining transient pressure and derivative responses only. When all the branches produce, the transient rate distribution is strongly controlled by the skin due to formation damage. Therefore, if transient rate distribution data, as well as the pressure, is recorded during the test, non-uniqueness in the interpretation of test data may be minimized. Although it is more expensive and time consuming, testing each lateral individually may provide more reliable estimates of formation properties and damage.
Correlating Good Well Design, Drilling and Cleanup Practices with High Well Productivity
Authors: Lacewell Jason L. , Burnett David B. 
Published: December 2007

Abstract
This paper presents three firsts: (1) a complete case study audit for a major oil company of well planning, well construction and well cleanup operations in a Gulf of Mexico (GOM) horizontal well, and ties these practices to well productivity, (2) one of the first horizontal well productivity analyses using early-time wellhead production data and wellbore cleanup data. (3) the direct, scaled correlation of laboratory data to field well productivity.
Our analyses include descriptions of the inter-disciplinary team style of well planning, laboratory testing programs using a new drill-in fluid, details of completion operations, and a report on cleanup operations performed on the well before flowback. During early time, the well's productivity was analyzed using two separate analytical methods. Results show that guidelines followed throughout the well construction process resulted in a highly productive well completion. Results of this case study are intended to advance the technology progression of horizontal well drill-in fluid design, filtercake cleanup, and to demonstrate the effect of conscientious planning practices on well productivity.
A Three-Segment Hydraulic Model for Cuttings Transport in Horizontal and Deviated Wells
Authors: Cho Hyun , Shah Subhash N. , Osisanya Samuel O. 
Published: December 2007

Abstract
A new approach of three-segment hydraulic model under two-phase (solid-liquid) fluid in annulus; i.e., horizontal and near horizontal section, vertical and near vertical section, and transit section is proposed to predict and interpret the cuttings transport mechanism. In particular, the model developed in this paper approaches a three-layer hydraulic model (stationary bed of drilled cuttings at the bottom, a moving-bed layer above it, and a heterogeneous suspension layer at the top) for horizontal and near horizontal sections. The existing two-layer model is modified for transit section, and one-layer model is used for the vertical and near vertical sections. This new mathematical model is presented to overcome the limitations in the existing hydraulic models used to predict cuttings transport when drilling a horizontal and deviated wells.
This paper specifically describes model development for each section, solution, and the simulation results of the integrated three-segment model. To ensure a comprehensive understanding the effects of parameters affecting cuttings transport efficiency, the simulation under hole cleaning mode was performed, that involves build-up of cuttings and cleaning out an existing cuttings bed. The results show how to obtain a reasonable pumping velocity and optimize rheology of drilling fluid with the possible lowest pressure gradient that might serve as an operational guideline during drilling. Moreover, the effects of various parameters that affect the efficiency of cuttings transport are discussed. These results are compared with published experimental data. The observed agreement and discrepancies are discussed, and further improvements on the current model are proposed.
Reservoir Management Through Horizontal Well Technology in Algyo Field
Authors: Palasthy G. , Joshi S. D. , Benedek L. , Kristóf P. , Pipicz V. 
Published: December 2007

Abstract
The first horizontal well was drilled in Hungary in 1989 and thereafter 60 horizontal sections were completed. The 76% of these wells are in the Algyo field, which is the largest HC accumulation in the Pannonian basin. After a 25-year production, the inaccessible hydrocarbons, which are deposited in unreachable parts of the reservoirs, have become producible by using horizontal wells. The target of the reservoir management was to maximise the long-term profit of the field by acceleration of reserves, reduction of gas and water coning, and by effective use of depleted gas reservoirs and existing vertical wells. In this paper we have summarised the reservoir management approach to enhance the value of the field.
In a complex turbidite sandstone reservoir the oil production capacity is doubled by infill drilling of horizontal wells. This has added 5.0 Million bbl of incremental reserves. In a multilayered part of reservoir Algyo-2 W-2, approximately 1.2 Million barrel of by-passed reserves have became producible after 25 year water injection.
By reducing gas and water coning in the reservoirs Csongrad-Del-1and 2, the oil production rates and the efficiency of well utilisation have been increased.
The depleted Maros-1 sandstone reservoir is now used for underground gas storage and existing gas wells were re-entered and completed to achieve higher daily peak rates.
A gas cap exists in the most part of the oil reservoirs. Development of the gas production well pattern started in the early 90’s. By decreasing the number of wells, improving the daily gas production capacity, and speeding up the exploitation of gas cap reserves, the NPV value was maximised.
In all cases, to reduce costs, existing vertical wells were re-entered and so the over all value of the assets was improved.
Oil Shale - A Reality in This Decade
Authors: Cha Chang Yul , Fernandes R.J. 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.

Abstract
A modified in situ oil shale process developed by Occidental Petroleum Corp. (Oxy), has both economic and environmental advantages compared with aboveground processing. The Occidental process requires processing. The Occidental process requires less capital investment, recovers a higher percentage of the oil in place, eliminates percentage of the oil in place, eliminates the surface disposal of spent shale and requires a minimum amount of "make-up" water for its operations.
One large scale and three pilot size retorts have been successfully processed under actual field conditions. A second large scale retort has been rubblized and is scheduled for ignition about April 1, 1977 and a third large retort is being formed. The processing of the first large retort showed that its performance could be predicted. In light of its past field work and predicted. In light of its past field work and the favorable economics, at current foreign oil prices, Occidental is ready for a commercial demonstration of its in situ technology. Occidental has recently joined with Ashland Oil for the commercialization of the Colorado "B" (C-b) Federal Lease Tract, using the Occidental modified in situ oil shale process. This paper will report on the progress to date of the Occidental field work progress to date of the Occidental field work and outline the development program for the C-b Tract.

Introduction
The potential for recovering oil from oil shale has been recognized since the early 1900's. A general description of the composition of the marlstone which forms the inorganic oil shale matrix and the organic polymer, called kerogen, is described in polymer, called kerogen, is described in reference 2. Therefore, such a description will not be repeated in this paper. One of the major reasons that oil shale yields a liquid fuel similar to petroleum is that the weight ratio of carbon to hydrogen for kerogen (7.8) approximates that of petroleum (6.2 7.5).
The shale oil reserves in the Green River Basin, particularly in Colorado, Utah and Wyoming, are estimated at some 1.8 trillion barrels. If only the oil shale deposits of at least ten feet thick with an average Fischer assay greater than 25 gallons of oil per ton are considered, the oil in place in per ton are considered, the oil in place in the three states has been estimated at 600 billion barrels (1). For more than 50 years, extensive development work has been conducted to find an economic and environmentally acceptable method of recovering oil from oil shale.
Inflow Analysis and Optimization of Slotted Liners
Authors: Kaiser T. M. V. , Wilson S. , Venning L. A. 
Published: December 2007

Abstract
Slotted liners have been used for many years to provide sand control in oil industry applications. They are relatively inexpensive to manufacture and tolerant of installation loads, but historically they have not been able to offer the very small opening sizes of wire-wrap screens for controlling production of fine sands. However, recent advances in slot manufacturing methods provide slot openings that match and surpass the size and tolerance of wire-wrap screens. Furthermore, slotted liners offer an advantage in providing a variable slot density that can be used to optimize inflow or outflow distributions.
In the development of its South Bolney reservoir, Marathon Oil Canada and Noetic Engineering Inc. performed an analytical evaluation of inflow characteristics for a new generation of commercially available slots. Several interesting conclusions were reached, the most significant being that inflow resistance depends much more strongly on slot density than on open area. The inflow characterization was also used to develop an optimized slot density distribution to promote more uniform production over the entire well. The slotting design was incorporated into a new well that was designed to control thermally induced loads, thereby avoiding the sand control characteristics of slotted liner being compromised.
An Innovative Biodegradation Enhancer and Multi-Purpose Bioremediation System for Oil Contaminated Sites
Authors: Kopp-Holtwiesche Bettina , Lauer Ursula , LeDren Isabelle , Groffe Didier 
Published: December 2007

Abstract
Cognis, part of the Henkel group, has developed a liquid product with lipophilic characteristics that can be applied to a number of environmental clean-up problems: oil contaminated soils, contaminated coast lines and off-shore drilling sites; and, in the event of large-scaled accidents, it can be combined with physical and mechanical pre-cleaning methods.
The Cognis product emulsifies hydrocarbons, making them disperse in water and thereby promoting biodegradation. With organic bound phosphorous and nitrogen the product also acts as a nutrient source for microbes. It forms a layer around contaminant molecules, thus reducing leaching of nutrients and fixing microbes to the contamiants. It boosts total cell count of local oil-devouring bacteria rapidly so that the natural self-cleaning capacity rises to a multiple acceleration. The product itself is of outstanding eco-compatibility: it is not washed-out into the groundwater, it does not remobilize contaminants, and it's active ingredients have a food and/or fodder permittance.
A large-scaled pilot test has shown that common agricultural fertilizers are not useful for bioremediation, because mineral nutrients were washed-out, and the biodegradation process was not enhanced.
Beside more cost intensive conventional ex-situ and in-situ bioremediation techniques, a special low cost technology was developed in a joint effort with IABG. This technique is especially suitable for contaminated zones located no more than 2 m below soil surfaces (D.R.O.P.: Decontamination and Revitalisation of Oil Polluted Land). While the product is applied by means of sprinkling systems and subsequently mixed into the soil, this technology is even applicable for water protection areas, wetlands or nature reserves. The overall cost of this measure is only a third of other well-known in-situ methods.
Economic Benefits From Automated Optimization of High Pressure Gas Usage in an Oil Production System
Authors: McKie C. J. N. , Rojas E. A. , Quintero N. M. , Fonseca J. R. Chacón , Perozo N. J. 
Published: December 2007

Abstract
An integrated solution was required to optimise the use of gas in a complex network installed for gas lifting operations, gas export and reservoir re-injection. The solution was required because the compression facilities represent a major element of the cost of operating the field and therefore it is important that the high pressure gas is used as efficiently as possible. It is also important that recommendations from the optimiser are implemented with minimal delay and therefore closed-loop optimisation was selected, which requires that the optimiser is integrated with the field's SCADA system.
The complexity of the system to be optimised presented a unique challenge. Traditional nodal analysis modelling techniques are generally not robust when applied to complex, non-hierarchical networks. Consequently, the Sequential Linear Programming (SLP) optimisation technique is applied to solve the computer model of the low pressure gas gathering system, multi-stage compression facilities and high pressure gas distribution system. The novel implementation of this technique simultaneously simulates and optimises since it is able to select the best combination of pressures and flowrates from the set of all combinations which will satisfy the problem constraints.
This paper describes the development of the optimisation application, the network and well models and the underlying mathematical techniques. The integration with SCADA and other databases is described, along with a discussion of how the form of the integration reflects the desired workflow for operating and optimising the field. Finally, the paper provides a quantitative assessment of the benefits realised by applying the optimisation application in the field. These benefits are obtained through increased oil production, reduced compressor fuel gas consumption and reduced venting of low pressure gas.
A New Approach to an Old Problem - Lightweight Liquid Concrete
Authors: Rucker Ross , Sauvageau Kent , Randolph Ted 
Published: December 2007

Abstract
Production in the San Juan Basin in Northwest New Mexico is predominantly gas at approximately 5000'-6000' TVD. While cementing, lost circulation makes it extremely difficult to have the top of cement at the required depth, providing zonal isolation and meeting regulatory requirements.
Due to the low fracture gradient of the Fruitland and Mesaverde (0.45 – 0.55 psi/ft) circulation is frequently lost when using conventional lightweight slurries to cement the casing strings, resulting in remedial work and additional time and expense.
The introduction of lightweight (9.5 ppg), high performance (fluid loss control, compressive strength, rheology), liquid concrete has made it possible to maintain full circulation while cementing casing strings. The system, based on optimizing the Packing Volume Fraction (PVF) of the dry blend, uses sized inert particles to provide a cost-effective solution to cementing these low-pressure wells.
The casing program has also been optimized to allow the cementing of both the Fruitland Coal and Mesaverde zones in a single operation with no losses.