bluuebunny/crossref_metadata_2025 huggingface dataset:
Appraisal of the HORSE CREEK Air Injection Project Performance
Authors: Clara C , Zelenko V. , Schirmer P. , Wolter Tom
Published: December 2007

This paper gives a current evaluation of the Horse Creek air injection project. The field, located in North Dakota, USA, is operated by TOTAL MINATOME CORPORATION, the US subsidiary of TOTAL. This light oil reservoir (32° API) has an OOIP of 46 MMBBLS. It was produced under natural depletion from 1972. Air injection started up in May, 1996. At this time, the oil production was at the low level of 300 bbl/d (after having reached 1600 bbl/d in 1984). But 16 months later, in September, 1997, production was increased to 700 bbl/d thanks to air injection.

The paper explains how air injection was decided in Horse Creek as a secondary recovery process. The principle of the air injection process into light oil reservoirs is also discussed. The project evaluation based on a geological review, numerical simulations and laboratory experiments is presented. The production data from the start-up of the air injection in May, 1996 to December, 1997 are given and the field performance appraised. A simulation update, performed in January, 1998, and integrating production data from 20 months of air injection, is finally presented.
PNC-Logging with Data Interpretation Approach to Characterize a Stratified Carbonate Reservoir
Authors: Sultan A. Junaid , Iqbal Ghulam , Furuya Masayuki
Published: December 2007

In layered carbonate reservoirs where high permeability streaks are present, it becomes challenging to keep track of injected water front movement. Pulsed Neutron Capture (PNC) surveys, in addition to other surveillance programs, served as a valuable tool to characterize premature water breakthrough in these heterogeneous reservoirs.

In this field, in many observation wells, time lapsed PNC log-interpretations have effectively been used to detect water encroachment in high permeability sub-zones. Time lapsed results also helped in developing a few type-logs, which show water front advancement in different sub-zones of various regions.

PNC interpretation results revealed behind casing water communication in certain wells. The findings assisted in carrying out reservoir management decisions.

PNC-log results were integrated with data obtained from Cores, PLT, and RPT to understand and identify water movement in different layers of the reservoirs. Water encroachment detected in different layers was also compared with the water saturation estimated in the layers based on simulation study.
A Rapid Standard Test for Screening Foam-Forming Surfactants
Authors: Zhong L. , Siddiqui S. , El-Hardalo S. , Islam M. R.
Published: December 2007

A new method is proposed for screening surfactants suitable for foam diversion purposes. Surfactant screening is an important task in the processes that involve the use of foam. Several screening methods have been developed, including static tests and porous media tests. However, they are neither dependable nor standard. Six different surfactants are tested in this study. These surfactants were selected among a foray of ‘best-performing’ surfactants supplied by six service- and chemical companies.

The new technique requires an inexpensive setup, a simple experimental procedure, and simple calculations. A new surfactant screening technique was developed in which optimum values of parameters such as ultimate liquid recovery, recovery at breakthrough, cumulative liquid produced to cumulative air produced (L/A) ratio, maximum blocking pressure, liquid mobility ratio (P2/P1) and breakthrough time during the porous media tests, were used to select the surfactants that are most likely to help diversion.

A series of coreflood tests, both in a single core and a dual-core, was conducted in order to compare the ranking that was obtained following the high-permeability porous media tests. The results are in excellent agreement. Also, bottle tests were conducted and it was demonstrated that the bottle test results do not match the results of high-pressure core flood tests. Some porous media tests were conducted in the presence of residual oil in the system. Results indicate that for screening of surfactants, it is not necessary to have oil in the system. This observation was supported by dual-core diversion tests conducted in the presence of oil. Similarly, there is no need to use acid during the screening process.

The proposed screening method can be applied in both foam acidization as well as enhanced oil recovery processes. The method uses porous media and standardizes the surfactant screening procedure.
ADCO's Environmental Performance
Authors: Al Habshi A H , Munger J ? , Walker C ?
Published: December 2007

ADCO's commitment towards the field of HSE activities, and specifically in protecting the environment, was reinforced by the implementation of the Environmental Management System (EMS) in 1996. Critical to the success of that system, environmental objectives and targets were set. Progress was measured monthly and reported quarterly through the use of Environmental Performance Indicators (EPI's) that were precisely developed for the purpose of tracking the improvement of ADCO's environmental performance. Complementary to that EPI reporting system, ADCO conducted both a Waste Inventory and an Air Emissions Inventory which were completed in 1997. HSE was further enhanced with the introduction of a drilling wastes management system.

The paper will present and discuss the environmental performance indicators; the result of it's Air Emission Inventory; the reduction in waste water disposal in ADCO's operational areas; and, highlights from waste management in drilling operations.
New Techniques in Wireline Formation Testing in Tight Reservoirs
Authors: Parkes R. , Carnegie A. , Neville T. , Hookway S.
Published: December 2007

Some of the main measurement objectives of wireline formation testing are to obtain data on formation pressures and gradients, fluid types and contacts and formation permeability profiles. Tight reservoirs pose many difficult problems when frying to achieve these objectives. The most notable problem is the supercharging effect which often invalidates reservoir pressures taken by the traditional technique of taking a small volume pretest (< 20 cc's). Another crucial objective is to perform measurements safely and cost effectively. This can be difficult to achieve since pressures in tight reservoirs can often require long periods of time to obtain, thereby increasing the costs of rig time, and the probability of tool sticking.

The key to advancing wireline formation pressure testing in tight reservoirs is to understand the fundamental causes of the problems, and to use this knowledge to develop methodologies and tools to solve them. Much progress has been recently been made in many areas. For example, the important mechanisms causing supercharging have been identified, and the associated effects have been successfully reduced or eliminated by recently developed methodologies and tools.

This paper discusses the problems of wireline formation testing in tight reservoirs, presents recently developed solutions to these problems and shows examples of where they have been applied. The major portion of the discussion will be devoted to supercharging. However, brief consideration will be given to some of other problems of tight reservoirs.

P. 419
Laboratory Development of a Novel, Simultaneous Cake-Cleanup and Gravel-Packing System for Long, Highly-Deviated or Horizontal Open-Hole Completions
Authors: Parlar M. , Tibbles R. J. , Chang F. F. , Fu D. , Morris L. , Davison M. , Vinod P. S. , Wierenga A.
Published: December 2007

The cleanup of the filter-cakes formed by reservoir drilling fluids is a challenging task in long, horizontal open-hole completions. Although various mechanical and/or chemical diversion techniques may be used, it is difficult to ensure contact of the breaker with the filter-cake throughout the whole interval when the reaction between the breaker and the filter-cake is relatively fast as in acid/CaCO3 reactions.

In this paper, we present novel, surfactant-based carrier fluids in a breaker (an acid, enzyme or an optimized chelant) solution which ensures contact of the breaker with the filter-cake throughout the whole interval when used in conjunction with shunt tubes for gravel packing open hole horizontal completions. The shunt tubes ensure complete packing of horizontal wells by allowing an alternate path for bypassing bridges that may form due to high leak-off rates. The surfactant/breaker carrier fluid ensures contact of the breaker with the filter-cake throughout the whole interval during gravel packing.

It is shown that the rate of cake removal depends strongly on the conditions under which the cake is formed, and it can be controlled to a large extent by varying the type of cleanup fluid. Several new fluid formulations are proposed for use as either single-step carrier/cleanup fluids in open-hole gravel packing or cleanup fluid in standalone screen completions. The effects of temperature, permeability, overbalance, surfactant concentration, and pH are investigated. A new much less corrosive carrier/cleanup fluid that attacks both CaCO3 and starch is proposed. This new fluid offers an order of magnitude lower cake removal rates compared to those with conventional acid systems. The low reaction rates promote a more uniform cake cleanup and should result in higher production rates. Laboratory data indicate that the rate of cake removal is essentially mass-transfer-controlled. Diffusion appears to be the limiting mechanism in most cases of practical interest, although convective mass transfer is also important with cakes formed over short-time periods and/or soaks with higher overbalances. Implications of the laboratory results on field applications are also discussed.
Squeezing a Multilateral Well Producing Fluids from Different Scaling Regimes
Authors: Bourne H.M. , Hibbert E. , MacDonald H. , McHugh P
Published: December 2007

This paper was prepared for presentation at the 1999 SPE International Symposium on Oilfield Chemistry held in Houston, Texas, 16-19 February 1999.
GOR-Control Foams: Demonstration of Oil-Based Foam Process Efficiency in a Physical Flow Model
Authors: Dalland Mariann , Hanssen Jan Erik
Published: December 2007

Production at high gas/oil ratio (GOR) is a problem in many reservoirs and occurs because of the high mobility of gas in the formation. Horizontal wells can be a solution to produce thin oil rims, but depending on the reservoir, these may also give unwanted gas production. Foam has been developed into an attractive GOR-control agent. Combining the use of foam with horizontal wells will possibly reduce the production of unwanted gas to an acceptable level.

Placement of foam barriers at the gas-oil contact plays a crucial role for a successful treatment. One option is the injection of an aqueous surfactant slug followed by nitrogen or methane gas injection. Since an aqueous solution has a tendency to segregate downwards, foam can only be created by following the surfactant with gas injection. A better injection scheme would be to inject a surfactant dissolved in a non-aqueous solvent having a lower density than the oil in place. Such a slug will segregate upwards to the gas-oil contact and form a layer. When the well is on production and gas tries to migrate through the surfactant layer a gas-blocking foam barrier will be formed.

As part of ongoing research towards qualifying the use of gas-blocking foam to control the GOR in producing wells, a new design of laboratory model of an idealised heterogeneous oil/gas reservoir penetrated by a horizontal well was developed. The physical flow model was used to study two phase production of oil and gas with and without the presence of a foam that has previously been shown to block gas efficiently in one-dimensional lab experiments. The results of these 2D model experiments are described in the paper and suggest that foam barriers are well suited for protecting horizontal wells in heterogeneous reservoirs.

The results include injection of foaming-agent solution, showing gravity-controlled placement, generation of gas-blocking foam by production start-up, and successful GOR reduction by the foam barrier, all proceeding as expected from previous work.
Management System of Safety and Environmental Protection in China Offshore Oil Industry
Authors: Jiang Dexiang
Published: December 2007

This paper presents the importance of offshore oil operation safety and lessens from serious accidents. CNOOC has explored a correct way for offshore oil safety management.

The paper describes the safety management system for China offshore oil industry and its content around eight areas.

The paper also introduces the recently plan and arrangement on safety and environmental protection management of CNOOC.

P. 13
Reservoir Evaluation Logging for Waterflooding Oilfields
Authors: Wang Shaomin , Yang Yuanjun , Jiang Wenda
Published: December 2007

The well logging techniques for waterflooded oilfield in China and the variations of lithological and petrophysical parameters for waterflooded formations are illustrated. The results of core measurement and the selection for logging series and interpretation methods are discussed. The remaining (or residual) oil saturation, water-cut, productivity and waterflood level are provided, which are the technological basis for the development plan adjustment and enhanced oil recovery.

P. 21
Integration Technology of Workover Equipment with Production Platform in Offshore Oilfield
Authors: He S. H. , Sun D. C.
Published: December 2007

This paper presents the integration technology of workover equipment with production platform in offshore areas. The environmental conditions, the structure style and the characteristics of the platform are described in the paper. It belongs to the conventional jacket platform. The production control facilities, the work-over rig, triplex pump, watch cabin and living accommodation are installed on the deck, which are all movable and disassembling parts. They can be moved to other similar platforms to perform work-over or remedial work, which will reduce the platform operation cost. Although the cost of the platform is 30% higher than that of the conventional platform, it is 50% cheaper than that of a movable work-over platform and the construction method is simple. As a new type platform, it can be used for production in offshore areas with a water depth of 5-18 m.

As more and more oil wells put into production in Chengdao island area, Shengli oilfield, Shandong province, oil testing water injection, well repair and work-over increases greatly. There are only two workover platforms in Shengli oilfield. Most oil testing and workover job is completed by the "Zuo Ye No.1" platform in the area where the water depth is more than 4m, it also need to perform the workover in offshore area in Liaohe oilfield. The "Zuo Ye No.2" platform can only work in the area where the water depth is less than 4m. Many work-over and remedial work especially oil testing after completion must be completed by drilling rig, which is a kind of waste to the drilling rig. The lack of the workover facility severely affected the production of offshore oilfield in Shengli and Bohai Bay.

Movable production platform is not suitable for the exploitation of offshore oilfield because of its long design and construction period, high expenses, and high engineering difficulty. In addition, the towing and jacking are complicated and its workover costs are very high with an average price of 2.5 million Renminbi Yuan each time. The research on the integration technology of workover equipment with production platform in offshore field is started in 1997 so as to exploit effectively the marginal offshore field. For an offshore marginal field with a production less than 30-50 t/d per well or per well cluster in initial days and 10-20 t/d later, it is not commercial to use current conventional production technology. It is important for the exploitation of offshore oilfield in Shengli and Bohai Bay to find out a new kind of platform. The platform can meet production requirements not only at present but also in the future, be competent to not only production but also work-over, can not only fixed on the production and workover platform but also move flexibly among production platforms.
Critical Aspects Experienced in Drilling a World Record Extended Reach Well in South China Sea
Authors: Zhang Ming Jiang , Zhang Wu Nian
Published: December 2007

In 1997, Xijiang 24-3-A 14 extended reach well (ERW) was drilled from Xijiang 24-3 platform. This well set a world record for a horizontal displacement of 8,062.7m at a measured depth of 9,238 m. it was needed to develop a satellite field about 8km from the existing platform. Due to the size of the field and number of the stacked sands, an S-shaped ERW was designed and drilled with an 80 tangent to the crest of the first reservoir sand. All the reservoir sands within the closure were intersected by dropping to a 54 inclination at total depth.

In addition to difficulties such as target tolerance, torque and drag, wellbore stability, normally expected in extended reach wells, several other obstacles were noted on Xijiang ERW. The critical problems included the unique operations in this area, relatively undersize of the rig and platform, near exploratory nature of the well.

This paper will discuss the drilling and completion of the ERW and how each of the critical problems was addressed and resolved.

P. 35
Application of Fractal Techniques in Reservoir Development
Authors: Shen Pingping , Liu Mingxin , Jia Fenshu
Published: December 2007

This paper mainly describes the methods and application of fractal techniques in reservoir development, including parameter analysis, modeling methods and application results of fractal techniques in the research on pore structure, distribution of heterogeneity of porosity or permeability and reservoir simulation. Some numerical algorithms in sofiware and its application effect are also discussed.

P. 53
The Technology and Methodology of Reservoir Geological Modeling in the Evaluation Phase of Oilfield Development
Authors: Jia Ailin , Mu Longxin , Xiao Jingxiu , Wang Zhengbiao
Published: December 2007

The evaluation phase of oilfield development refers to the period from the discovery of an ojlfield to the development. In this time, only one or a few wells have been drilled, and usable data is very limited. But in order to develop the oilfield successfully, a geological model, which can reflect the basic character of the reservoir (conceptual model) must be built. Thus, a couple of conflicts between data and study come out.

Over past 10 years, many new oilfields have been discovered in China, especially in western China, and the geological conditions and usable data are very different from each other. Through 10 years of research and application in the new oilfields, many new technologies and methodologies in geological modeling matched to different oilfields with various geological characteristics and data have been developed, including:

Based on detailed geological and sedimentary researches, we integrate all useful data (seismic, logging, geologic statistic and so on) to build geological model and to evaluate the reservoir heterogeneity.

A set of new technology and methodology has been used and developed according to the character of different oilfields, which includes high resolution seismic technology under the control of well data, stochastic modeling under the control of geology, high resolution stratigraphy correlation and so on.

The modeling steps and methods according to different geological and data conditions and requirements of development plans are generalized.

With the development and application in many new oilfields, we found the models built by above methods are successful.

P. 67
Practice & Knowledge Gained from the Development in the Pilot Area, SZ36-1 Oil Field
Authors: Liang Huiwen , Jing Fengjiang
Published: December 2007

The recovery features of conventional water injection is. summed up based on 4 years production data from the pilot test area in SZ36-1 oilfield. Combined with the analysis on reservoir characteristics, fluid properties and production techniques for their influences on development results, some basic knowledge of certain development issues is gained and presented in the paper.

P. 75
High Temperature and High Pressure Well Drilling Practice in Ying-Qiong Area South China Sea
Authors: Zhang Yong , Duan Yisheng
Published: December 2007

There are lots of potential risks and difficulties in the high temperature and high pressure well drilling. Ying-Qiong Area South China Sea is one of the areas in the world where high pressure and high temperature coexists. This paper reviews the high temperature and high pressure well drilling operations conducted by China Offshore Oil Nanhai West Corporation in the Ying-Qiong Area South China Sea and probes the technology applied to the high temperature and high pressure well drilling operation. It emphasizes on the prediction of formation pore pressure, well casing program design, casing wear prevention and well drilling technical measures, etc.

P. 95
Combined Using SSAW and LSAW Pipes for Oil & Gas Pipelines - A Reliable and Economic Approach
Authors: Huang Zhiqian , Liu Wencheng
Published: December 2007

The success of combined using SSAW and LSAW pipes for oil and gas pipeline in large scale is an important breakthrough of metallurgical and steel pipe manufacturing technology in China. Based on the greatly improved quality of SSAW pipe, this technology has brought up a very reliable and economic approach for pipeline Construction and a promising prospect of expanding the use of SSAW pipe. CNPC has applied this technology to construct many oil and gas pipelines both in and outside China successfully.

P. 103
Cold Production of Thin-bedded Heavy Oil Reservoir in Henan Oilfield
Authors: Hu C. , Liu X. , Wang J. , Song Z. , Fan Z. , Yang F
Published: December 2007

The heavy oil reservoirs in Henan oilfield are mainly thin-bedded viscous and unconsolidated with viscous oil. Many of which are suitable for cold production. Lab experiments show that high permeability channels can be created in the reservoir when a large amount of sand is produced, and that the oil displacement efficiency is significantly improved in presence of dissolved gas. Field pilot shows that the fluid is produced in a foamy oil form with sand-cut of 2-20% (in volume) and oil production of 16-30t/d, which is over 10 and 5 times as much as that of conventional recovery and cyclic steam stimulation in the same reservoir respectively.

P. 119
Studies on the Untabulated Reservoirs Development in Daqing Lasaxing Oilfields
Authors: Wang Qimin , Song Yong , Cheng Baoqing , Liu Chunlin
Published: December 2007

The reservoirs of Daqing oilfield are a set of fluvial and deltaic sediments deposited in the inner continental shallow lakes and basins. In the long course of complicated sedimentation, sediments are generated not only in the high-energy environment, but also in the low-energy one characterized by short supply of detrital materials. The latter is mainly oil-spotted and oil-soaked muddy siltstones distributed on the top and in the bottom of sediments and in their poorly lithological position. Generally they are not within the limit of effective thickness, so they are not arranged into the reserves list, and then named untabulated reservoirs.

This kind of reservoir's individual layer is thin and its area is small, but the reserves potential is great. Generally speaking they are communicated complicatedly with good oil layers, if they are divided as barrier zones, t will influence the whole effects of oilfield development, so studies on the untabulated reservoirs will have great value to improve the overall effects of Daqing oilfield development.

Through studies and field tests in the untabulated reservoirs of Lasaxing oilfields, the geological characteristics and potential distribution have been clearly known and a set of measures have found out to develop these untabulated reservoirs, thus the theoretical and practical bases have been accumulated for further tapping the potential of the untabulated reservoirs.

P. 125
Simulational Study of Viscous Fingering in Fractured Reservoirs
Authors: Zhang J.H. , Liu Z.H. , Qu S.X.
Published: December 2007

Viscous fingering phenomena occurring in fluid displacement process are simulated by using the fractal theory in heterogeneous reservoirs. Networks of random fractures are constructed using successive random adding method in two dimensional areal simulations. A modified fractal growth model, in which the interfacial tension effects in the boundary of displacing and displaced fluids are taken into account, is employed to simulate the immiscible displacement of native oil by injected water in fracture-network reservoirs. The results suggest that the geometry of a fracture network influence upon the displacement process significantly. Increasing fracture width, or increasing linear density of fractures, or decreasing Hurst exponent of a fracture, will lead to the dominant movement of driving fluid along the fractures. The fractures control the flooding pattern. Fingers grow easier at the orientations of fractures. Therefore, the areal sweep efficiency decreases, but the sweep efficiency along fractures increases. Furthermore, the distribution of a fracture network also affects the development and evolution of fluid displacement.

P. 273
An Analysis of Helical Buckling of Long Tubulars in Horizontal Wells
Authors: Deli Gao , Liu FengWu , Xu BingYe
Published: December 2007

It is difficult to determine real helical configuration by the current energy method. This paper describes an analytical solution based on equilibrium method, which represents the real configuration of helically buckled tubular subjected to axial and torsion loading in horizontal wells. New results of axial changes, the maximum bending stress and contact force in tubular are derived from the solution.

P. 517
A Fully Implicit Parallel EOS Compositional Simulator for Large Scale Reservoir Simulation
Authors: Wang P. , Balay S. , Sepehrnoori K. , Wheeler J. , Abate J. , Smith B. , Pope G. A.
Published: December 2007

A fully implicit parallel equation-of-state (EOS) compositional simulator for large-scale reservoir simulation is presented. This simulator is developed under the framework named IPARS (Integrated Parallel Accurate Reservoir Simulator) and is constructed using a Newton-type formulation. The Peng-Robinson EOS is used for the hydrocarbon phase behavior calculations. The linear solvers from the PETSc package (Portable Extensible Toolkit for Scientific Computation) are used for the solution of the underlying linear equations. The framework provides input/output, table lookups, Fortran array memory allocation, domain decomposition, and message passing between processors for updating physical properties in mass-balance equations in overlapping regions. PETSc handles communications between processors needed for the linear solver.

Many test runs were performed with up to four million gridblocks for a dry-gas injection process on an IBM SP machine and half a million gridblocks on a cluster of 16 PCs. Results indicate that the scalability of the simulator is very good. The linear solver takes around half of the total computational time for homogeneous reservoirs. For layered heterogeneous reservoirs, the linear solver took a larger fraction of the total computational time as the permeability contrast increased. The time for the communication between processors for updating the flow equations is insignificant.

The PC cluster is roughly a factor of two slower than the SP for parallel runs, which is very encouraging. This factor is strongly related to the hardware configuration of the computers, which is detailed in the paper.
Decision-Driven Reservoir Modelling: The Next Big Thing
Authors: Gawith D. E. , Gutteridge P. A.
Published: December 2007

In the past few years there has been a change in reservoir modelling from using 2D maps to a 3D workflow involving detailed shared earth models, upscaled for reservoir simulation. This change has brought an improvement in the quality of simulation models through incorporating more geological features of reservoirs. However, in many cases, this process is slow and impractical. Teams find they cannot update the complex models frequently enough, or carry uncertainty, because current technology can not cope. Our task now is to take the shared earth model forward and realise its potential.

This paper introduces a new approach to reservoir modelling: DDRM, which is aimed at meeting the challenges of the new business environment. It involves creating and using reservoir models which are just as complex as they need to be, and bringing uncertainty into predictions more thoroughly than before. This requires advanced reservoir modelling technology, with new techniques such as: scale-independent non-grid-based design, model-detail realisation on the fly, merging static and dynamic elements, and uncertain prediction from uncertain models.

The new approach is illustrated by a case study in probabilistic ranking of well-locations on an oilfield under development. The business decision is where to put the next wells, and the pace of development makes it impossible to update and run conventional large reservoir models to evaluate all the possibilities. The DDRM solution is quick and appropriate, matching method to question. New technology used in this case includes model construction with uncertain objects, dynamic characterization by streamline simulation on the fly, detail created locally when required and automated, rapid model updating.
Delumping Compositional Reservoir Simulation Results: Theory and Applications
Authors: Barker John W. , Leibovici Claude F.
Published: December 2007

A recently published method for delumping the results of a compositional reservoir simulation is used to predict variations in composition of the produced fluids during the life of a real gas condensate reservoir.
Domain Decomposition Methods and their Application to Modeling of the Performance of Horizontal and Slanting Wells in the Anisotropic Reservoirs
Authors: Ibragimov A. I. , Baganova M. N. , Nekrasov A. A.
Published: December 2007

In this paper analytical simulator for modeling of the wells performance is presented. The proposed method is based on iterative algorithm and domain decomposition principle (with and without overlapping) reducing the drainage problems in initial domain with complicated structure, heterogeneous properties and mixed boundary conditions to problems in standard (simple) homogeneous domain with uniform boundary conditions. The developed method has been proved in both stationary and transient cases.

For the numerical realization special analytical approximations of Newtonian and Heat Potentials were used. The computational experiments allowed to analyze the impact of the geometry of the "resevoir+well" system on the production index and to infer several Flow Rate (F-R) Formulae for the strongly Horizontal well (HW), Slanting well (SW) and dual lateral HW.

The developed analytically numerical method and the F-R Formulae have been validated and proved to be highly precise.
Curvilinear Local Grid Refinement: Part 2–Rapid Grid Generation, and Further Applications
Authors: Ghosh S.
Published: December 2007

Rapid generation of a local, orthogonal, curvilinear grid around a well requires numerically inexpensive methods for computing curvilinear gridblock pore volumes. An adaptive step size fourth-order Runge-Kutta integration is combined with adaptive discretization of the computational domain for fast pore volume determination. Adaptivity is shown to be critical for fast integration. A coning application is used to compare and contrast several grid refinement schemes.
Aquifer Configuration Estimation Through Inverse Problem Solution
Authors: Zakirov Iskander S. , Zakirov Ernest S.
Published: December 2007

It is well-known that the configuration of aquifer, its spatial extent and reservoir properties significantly influence the whole process of gas/oil recovery. The impact of aquifer is the most essential when field is developed under the depletion drive. In this paper a method to evaluate unknown configuration of aquifer conditioned to production history data has been developed.
Re-Examine Insert Chamber-Lift for High Rate, Low BHP, Gassy Wells
Authors: Winkler H. W.
Published: December 2007

Chamber-lift is a form of intermittent gas lift (GL). The chamber installation design determines the success of this type of GL operation. There are three primary reasons for selecting chamber-lift to GL a well:

to lower the depth of gas injection in a low flowing BHP well with a long perforated interval or open hole, to fully utilize an available injection-gas pressure that significantly exceeds the flowing BHP in terms of starting liquid slug length, and to attain the lowest possible average flowing BHP by reducing the fluid-head backpressure for a given liquid feed-in.

Although there are numerous variations in the physical design of a chamber, the two fundamental types are the two-packer and the insert bottle type for collecting the well fluids. The two-packer chamber utilizes the casing annulus for accumulation of the well fluids. The insert type of chamber is usually fabricated from the largest pipe that can be safely run inside of the casing or open hole.

Chamber location and size relative to the working fluid level, injection and formation gas venting, supplementing injection gas for lifting the slug and utilizing the chamber-lift principle can be the difference between efficient and inefficient chamber-lift operations. The purpose of this paper is to outline and illustrate the chamber-lift design considerations that are not fully explained in previously published literature on insert type chambers in high rate, low flowing BHP, gassy wells.
Phenomenological Filtration Model for Highly Compressible Filter Cakes Involving Non–Darcy Flow
Authors: Civan Faruk
Published: December 2007

A phenomenological model is developed based on the volumetric conservation of the particles and carrier fluid and Forchheimer's inertial flow law. The model incorporates empirical constitutive relationships for the permeability and porosity variations of compressible cakes retaining fine particles. The simulation of a serious of filtration scenarios are presented to demonstrate the parametric sensitivity of the model. It is determined that permeability impairment by fine particles retainment and pore throat clogging in the filter cake is increasingly induced by cake compression. It was also determined that constant pressure filtration limits the filtrate invasion more effectively than constant rate filtration and the nonDarcy flow effect is more significant during the initial period of the filter cake formation. The cake formation models developed in this article can be used for prediction of the effects of the compressible filter cakes involving the drilling muds and fracturing fluids.
Analysis of Pressure Derivative Data of Finite-Conductivity Fractures by the "Direct Synthesis" Technique
Authors: Tiab Djebbar , Azzougen Athmane , Escobar Freddy H. , Berumen Sergio
Published: December 2007

This paper extends Tiab's Direct Synthesis technique1,2 for interpreting the behavior of the pressure and pressure derivative data of a well intersected by a finite conductivity hydraulic fracture. In this technique log-log plots of pressure and pressure derivative data of a pressure drawdown or pressure buildup test are analyzed without using the type-curve matching or regression procedures.

A log-log plot of pressure and pressure derivative versus test time for a fractured well in a closed system may reveal the presence of several straight lines corresponding to different flow regimes; bilinear flow, linear flow, infinite-acting radial flow, and pseudo-steady state flow. The slopes and points of intersection of these straight lines are unique and therefore can be used to calculate several well, reservoir and fracture parameters: permeability, skin factor, wellbore storage coefficient, fracture conductivity, half-fracture length, and drainage area.

It is found that equations corresponding to the points of intersection are very useful in checking on the parameters obtained from the slopes, when the pressure derivative curve is not smooth. A new equation is derived for calculating (a) the half-fracture length in the absence of the linear flow regime straight line of slope 0.5 such as in the case of low conductivity fracture, (b) the fracture conductivity in the absence of the bi-linear flow line of slope 0.25, and (c) the skin factor in the absence of the infinite acting radial flow line such as in the case of a short test.
Global Greenhouse Gas Emissions Inventory Methodology
Authors: Schievelbein Vernon , Lee Arthur
Published: December 2007

An emission inventory is a powerful, multi-purpose tool used by regulators, public interest groups and other stakeholders in the environmental protection arena. Given growing conviction that market-based approaches are more effective than command-and-control regulations, inventories will increasingly be used to influence the behavior of companies in the market place. Carbon dioxide and other greenhouse gas emissions are becoming important elements in the emissions inventory. Under the Framework Convention for Climate Change and now the Kyoto Protocol, the emissions inventory of nations as well as the regulated community will come under additional scrutiny as emissions targets and time tables will have to be met once the Protocol is put in place.

Data accuracy and consistency, and the cost and timing of delivery of data from Texaco's worldwide business units were important considerations in the selection of Texaco's emissions inventory methodology. This methodology is based primarily upon the coupling of emission factors with fuel or product throughput, or equipment component count. The Texaco emission source list is comprehensive and, in some cases, the emissions factors used are based on more recent source measurements with greater accuracy. This paper describes the basis for the generation of a Texaco worldwide emissions inventory.
Appropriate Uses of Air Quality Models for Developing Regional Ozone Plans and Related Planning Issues: Issues and Problems for Both the 1-Hour and 8-Hour U.S. Ozone Standards as they Affect Petroleum Production Areas
Authors: Ziman Stephen D.
Published: December 2007

In July 1997, EPA revised the National Ambient Air Quality Standard for ozone to an 8-hour average of 80 parts per billion standard. Oil exploration and production areas in California and adjacent to the Gulf Coast states will be impacted by this change, as these areas will most likely be nonattainment for the new standard.

The 1990 Clean Air Act Amendments led to many areas in the United States undertaking ozone modeling in order to fulfil the requirements for demonstrating attainment of the one-hour 120 ppb ozone standard. However, this approach, which assumes that a deterministic model can be used to predict emissions reductions that will result in no exceedance of a probabilistic standard is very questionable. Further, in reality, the requirements do not encourage agencies to explore the ramifications of different strategy options, beyond that of the attainment strategy.

Recent work suggests that the new 8-hour ozone standard may be impossible to attain for a number of areas, including the oil production area in the San Joaquin Valley. Consequently, decisions on emissions reduction strategies for these areas need to be based on considerations other than demonstrating attainment. Among these considerations are maximizing reduction of population exposure, reduction in the areal extent of ozone concentrations above the standard, and reduction of the peak.

Also, because recent studies have highlighted some real concerns with the adequacy of ozone modeling, a new approach to planning is recommended. This would utilize a process that would use both modeling and non –modeling information to develop a plan, along with an iterative review of the modeling and analysis of changes in ozone over 5 to 6 years after enactment of the plan to determine if the original strategy was on target.

In addition, the issues described for ozone modeling also are relevant for other planning requirements such as for the PM 2.5 standard and regional haze regulation. These additional problems will be highlighted at the end of this paper.
Greenhouse Gas (GHG) Mitigation and Monitoring Technology Performance: Activities of the GHG Technology Verification Center
Authors: Masemore Sushma , Kirchgessner David A.
Published: December 2007

The Greenhouse Gas (GHG) Technology Verification Center (the Center) is a public/private partnership between the Southern Research Institute (SRI) and the U.S. Environmental Protection Agency's (EPA's) Office of Research and Development. It provides independent third party testing of the performance of GHG mitigation and monitoring technologies, and was established in response to the belief that there are many viable environmental technologies available which are not being utilized for the lack of credible third party performance testing and reporting. The Center is part of EPA's Environmental Technology Verification (ETV) Program, which has established 12 verification centers to evaluate a wide range of technologies in various environmental media and technology areas. The Center has published the results of its first verification: use of a phosphoric acid fuel cell to produce electricity from landfill gas. It has also initiated three new field verifications, two on technologies which reduce methane emissions from natural gas transmission compressors, and one on a new microturbine electricity production technology.
Pollution Prevention/Best Management Practices Training Manual for the New Mexico Oil and Gas Industry
Authors: Weinrach Jeffrey B. , Friday Dave , Kowalski Judy
Published: December 2007

This paper describes the development of a pollution prevention/best management practices manual for the New Mexico oil and gas industry. The manual provides the tools and information needed to develop a comprehensive pollution prevention-based environmental management system. The manual consists of two volumes. Volume 1 describes a set of decision-support tools and techniques that are being advocated by the state of New Mexico to help businesses incorporate pollution prevention into their key business functions. Volume 1 also provides examples of pollution prevention opportunities for four oil and gas sectors: exploration and production, pipeline operations, gas processing, and oil field services. Volume 2 provides a glossary of pollution prevention and waste management alternatives for the common oil and gas waste streams and cross-reference keys to the four oil and gas sectors described in Volume 1.
Minerals Management Service Environmental Monitoring Program
Authors: Irion J. B.
Published: December 2007

The Minerals Management Service (MMS) develops and includes mitigative measures or reminders of lease stipulations in the environmental documents that are prepared to assess the effects of proposed oil and gas activities in the Gulf of Mexico Outer Continental Shelf (OCS) Region. At present, the MMS imposes certain mitigative measures in environmental documents, primarily Categorical Exclusion Reviews (CERs) and Environmental Assessments (EAs), to minimize or preclude impacts from proposed operations. In 1997, MMS instituted a Seafloor Monitoring Program to verify industry compliance with environmental mitigative measures and to ensure protection of significant seafloor habitats and archaeological properties. The Monitoring Program is twofold. First, it requires operators to demonstrate compliance with avoidance requirements by providing "as-built" maps showing anchor locations with their construction reports. Secondly, field checking by MMS personnel using high-resolution side-scan sonar and/or MMS divers verifies that protected features were avoided.
Costs and Benefits of the E&P MACT Rule: Application of a Regulatory Simulation Model
Authors: Willis Wayne I. , Johnson Nancy , Ranganathan Raja
Published: December 2007

This paper describes the components of DOE's Regulatory E&P Air Model (DREAM) and its use in preparing comments on EPA's 1998 E&P Maximum Achievable Control Technology proposed regulation. DREAM, developed by ICF Resources Incorporated, uses detailed oil and gas well-level data to construct bottom-up estimates of both the costs and benefits of regulations related to air emissions from E&P operations. DREAM consists of a Cost Module and a Benefits Module. In addition to these two components of DREAM, the Cost Module was designed to provide inputs for two of DOE's reservoir-level oil and gas supply models (i.e., the Gas Supply Analysis Model [GSAM] and the Crude Oil Policy Model [COPM]). These models allow DOE to estimate the impacts of increased compliance costs on oil and gas production, well abandonment rates, and the size of economic reserves.

DREAM considers not only the costs of new regulations, but also the human health benefits of reduced emissions. To do this, a simplified air dispersion and risk algorithm is run for each producing field. The resulting individual cancer risks (based on benzene exposure) are superimposed on the population densities surrounding each oil or gas field. This provides a total number of cancers and deaths that would be expected each year. By applying various economic estimates of the "value of life" and the "value of health" to the resulting estimates, health benefits can be directly compared with compliance costs using the common metric of dollars. The most important innovation of this model is that it allows the user to identify the break-even point where social costs (i.e., compliance costs, lost oil production, lost employment) are offset by social benefits (i.e., reduction in the number of cancer illnesses and deaths). Results of two model runs are presented in the paper.
An Evaluation of Protective Concentrations for Hydrogen Sulfide in Produced Water Discharged in California Outer Continental Shelf Ocean Waters
Authors: Glickman Andrew H. , Tischler Lial F. , Ford William H.
Published: December 2007

Hydrogen sulfide (H2S) can be present in produced water discharged from production platforms along the Southern California Outer Continental Shelf (OCS). An assessment of the toxicity of H2S to marine organisms was conducted to determine if adverse effects could occur due to California OCS produced water discharges.

Hydrogen sulfide toxicity is attributable to the undissociated H2S, which comprises approximately 3 - 8% of the total discharged sulfide in seawater. The dissociation of H2S is a function of temperature, pH, and salinity. H2S is not persistent in seawater and rapidly degrades by reacting with oxygen to form nontoxic thiosulfates. The oxidation half-life of H2S in seawater is reported to be between 0.4 to 3 hours. Data in the scientific literature indicate that marine species are less sensitive to H2S than fresh water species. Lethal effects to marine species have been reported to occur at concentrations as low as 20μg undissociated H2S/L in 96-hour laboratory exposures. No observable effect concentrations based on results from chronic toxicity bioassays that assess growth and developmental effects have been reported as low as 4 μg undissociated H2S/L.

Produced water data from three production platforms were analyzed to determine the potential impact of H2S on marine life passing through the effluent plume or residing outside of the mixing zone. Calculations of the undissociated H2S at the edge of the mixing zone, taking into account natural oxidation of H2S to nontoxic thiosulfate, and comparing those concentrations with conservative chronic toxicity values, demonstrate that H2S in California OCS produced water discharges should not present a hazard to marine aquatic life.