bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesizing of Dispersant for MTC Design and Its Effect on Slurry Rheology
Authors: Jirul Hou , Zhongchun Liu
Published: December 2007

A new method of obtaining improved zonal isolation using drilling fluid solidification technology has been developed. A water-base drilling fluid is converted into a cementitious slurry by the special method, is called simply MTC(Mud To Cement).The MTC technology used for cementing operation can improve the quality of cementing and reduce the disadvantageous effect resulting from flocculation in the mixture of drilling mud-cement and cracking of solidified cement as the filter cake and drilling fluid in washed out sections thereby contain a hydraulic material.The dispersant's synthesizing and its effect on slurry rheology are the base of MTC technique application.This paper provides two methods of which the dispersant is synthesized by using fractions of C9 which are the by-product of Daqing ethene unit. The dispersant is cheaper, and it can be used for MTC design by experiment's verification. The effects of amounts of dispersant and mud on the rheology of MTC slurry are studied and discussed. The results show that the thickening time of MTC slurry is extended clearly with mixing of dispersant, and the mobility of slurry is improved. We find that there is a low mobility or high consistency region, when MTC slurry is making up. The appropriate measures for improving quality of MTC are provided in this paper. Moreover, the rheological model of MTC slurry is studied. Through lots of calculation, the H-B model is the most accurate for describing MTC slurry.Last, the application of MTC technology in Changqing field is introduced.
Overbalanced Perforating Field Study in the Tubb Sand, Bravo Dome Field
Authors: Grieser Bill , Smith Craig C. , Bertrand Bert
Published: December 2007

This paper provides results of a study comparing several parameters from 40 wells that were fracture-stimulated with conventional perforating techniques to 30 wells fracture-stimulated with overbalanced perforating (OBP). All wells are in the Bravo Dome Field and are producing from the same formation. The parameters used for comparison are (1) interval length and depth, (2) number of perforations and phasing, (3) perforating technique, (4) average and maximum bottomhole calculated treating pressure (BHTP), (5) proppant volume to job volume ratio, and (6) production results. There were two opinions on the benefit/risk of using OBP as an initial step in completing wells that may require fracture stimulation. One opinion suggests that OBP reduces near-wellbore tortuosity and creates a dominant fracture geometry, resulting in lower injection pressures and reduced chance of early screenouts. The other opinion suggests that OBP increases tortuosity and creates multiple fractures that could lead to high injection pressures and early screenouts.
Borate-Crosslinked Fluid Rheology Under Various pH, Temperature, and Shear History Conditions
Authors: Shah S. N. , Lord D. L. , Rao B. N.
Published: December 2007

The oil and gas industry has now long been aware of the fact that the rheological characterization of crosslinked fluids under field simulated conditions is very difficult. Particularly, the testing of borate-crosslinked fluids under realistic conditions for better understanding of their rheological behavior, is very complex. For this purpose, the Gas Research Institute (GRI), the U. S. Department of Energy (DOE), and the University of Oklahoma jointly established the Fracturing Fluid Characterization Facility (FFCF) which includes a pilot-plant scale, high temperature, high-pressure simulator (HPS) coupled with a fluid pre-conditioning system. Employing the field-size equipment of the FFCF and field-simulated procedure, various borate-crosslinked fluid formulations are tested and evaluated for their rheological responses.

This paper presents the results of pre-conditioned fluid rheology tests conducted with borate-crosslinked Guar and HPG gels employing the HPS over a range of pH from 9 through 11, subjected to varying levels of shear history and temperature. The network structure of these crosslinked fluids at any time is dependent on the current shear state, past shear history, and borate ion concentration which in turn depends on pH and temperature. Even though the effect of pH and temperature on the borate ion concentration is relatively well understood, the characterization of the shear state of the gel at field conditions is still in its infancy. In this investigation, test fluids are subjected to all conditions, to the maximum degree practical, experienced by a fracturing fluid in the field, including its formulation in surface equipment, its injection through tubular goods and perforations, and its flow and heatup in the fracture. Besides the effects of polymer type, temperature, and fluid pH, the effects of shear history on the rheology of borate-crosslinked fluids are also investigated. The presented results show dramatic effects of shear history on the rheology of borate-crosslinked gels which have been ignored in previous investigations. Certain gel formulations corresponding to specific pH and temperature conditions, were found to be shear history insensitive. Furthermore, these shear history insensitive formulations were also found to exhibit an optimum viscosity which was independent of temperature over the range of ambient to 185 °F.
Drilling Short Radius Dual Lateral Wells in Oklahoma: An Operator's Experience
Authors: Ellis Charles A. , Samuel G. Robello
Published: December 2007

Drilling lateral wells from the same vertical well to improve hydrocarbon production has been successfully applied in many fields. This paper discusses the operator's experience in drilling short radius dual laterals from the same vertical wellbore in the Burbank Sand of the Burbank Field of Osage County, Oklahoma. The laterals were sloped to intersect the many stratified sands and allow gravity drainage to act later in the life of the well.

The completion and difficulty in removal of formation damage from use of xanthan gum from polymer sweeps are discussed.
Something Different In Down Hole Pumping
Authors: Anderson Howard C. , Watson Brock , Earnest Dale , Walla Andrew , Folmar Eddie
Published: December 2007

This paper describes a new and different approach to conventional beam pumping with a subsurface pump and sucker rod string. The beam pumping cycle takes the rod string from tension on the up stroke to compression on the down stroke. Minimizing the compressive forces on the down stroke, creating a higher minimum load aids in extending the service life of tubing, rods and pump. This can be done by the lower portion of the rod string being larger sucker rods or sinker bars or by proper sizing of the pump plunger or a combination of both along with proper stroke length and strokes per minute.

Data presented in this paper shows another means of keeping the rod string in tension by use of a different type of subsurface pump. The fluid load on the areas of the pump act to increase the down stroke load. This down stroke load tends to keep the lower end of the sucker rod string in tension rather than allowing it to go into compression. This paper presents the theory of a different kind of subsurface pump backed up by field data showing the benefits of this pump.
Biotechnological Treatment Removes Xanthan-Based Skin Damage
Authors: TjonJoePin Robert M. , Brannon Harold D. , Beall Brian B.
Published: December 2007

Conventional reservoir drilling fluids typically consist of xanthan-based polymers to optimize recovery of drill cuttings and reduce friction or torque during the drilling operations. Previously conducted laboratory studies have indicated that the damage produced by these types of xanthan-based drilling fluids can be easily removed. Field data, on the other hand, has indicated that substantial amounts of polymeric damage remain in the formation. Even though these psuedoplastic, non-thixotropic, xanthan-based drilling fluids exhibit low shear rheologies during the operations, they can contribute to tremendous amounts of skin damage. This insufficient degradation of filter cake may impede flow and dramatically reduce formation permeability hence well productivity.

Recent extensive research was conducted to develop a treatment which could effectively reduce this type of polymeric damage. A novel biotechnological treatment has been developed, which effectively removes xanthan-based filter cakes or skin damage at temperatures from 70°F to well over 250°F.

Core flow evaluations have shown that multi-fold improvements are achieved with this optimized biotechnological removal treatment. A detailed study of the laboratory and field case histories are presented. Average incremental production rates of the treated wells were significantly improved, clearly demonstrating the effectiveness of this removal system.
New design of a floating storage and production unit
Authors: de Werk E.J.
Published: December 2007

Where a pipeline cannot be employed for technical or economic reasons, the existence of facilities for temporary storage is a prerequisite for the exploitation of an oil well. The choice of an offshore storage system, of which a number of types exist, is largely governed by environmental factors at the field. The advantages and disadvantages of existing storage systems are reviewed and the design of a new "spar" type storage unit discussed. This unit is mobile, yet is well suited to use in adverse weather conditions.

In addition to its role as a storage tank and a single point mooring buoy, the unit also serves for production. The design criteria, the oil system and the single point mooring section are dealt with, and also aspects of the fabrication of the unit and the methods employed to position and recover it.

Introduction

It is envisaged that energy requirements in the next few decades will be met from undersea sources and that the exploitation of oil wells will increasingly involve operations in deeper water and at greater distances from coasts.

Although not new, the storage of oil at sea is a new aspect of offshore technology and one which is in the course of development. Various storage facilities have been developed in recent years, each with its specific advantages and shortcomings. In most cases, such facilities are designed for a particular location and are more or less rigidly attached to the seabed, or resemble a ship's hull and are anchored by means of a number of chains or are moored to a single point mooring system.

Where large-volume storage units are involved, surface vessels can be used for the purpose only if the environmental factors at the location are such that no violent motions occur which impose heavy stresses on the anchorage system.
Field Applications of ERD Hole Cleaning Modeling
Authors: Hemphill Terry , Pogue Tom
Published: December 2007

SPE/IADC Members

With the ever-increasing measured depths and horizontal displacements in extended-reach (ERD) wells, good hole cleaning remains a major challenge. Recently a hole cleaning model for fluids in laminar flow was presented to the industry. Since its introduction, the model has been used on many occasions to characterize hole cleaning efficiency in post-well analysis, evaluate fluid performance during the drilling of ERD wells, and to predict fluid rheological properties and pump output levels for optimum cleaning in pre-well planning. In this paper, four field applications of the hole cleaning modeling in ERD and deviated wells are discussed. In these cases, the hole cleaning model was used to predict intervals of hole cleaning problems and identify certain ranges of fluid rheological properties that promoted good cleaning.

Introduction

The hole cleaning model (hereinafter referred to as "the model") utilizes the following to mathematically describe the ability of a drilling fluid in laminar flow to clean drilled cuttings out of a wellbore:–Herschel-Bulkley rheological modeling of drilling fluids - Annular velocity modeling valid for concentric and eccentric drill pipe cases–Particle settling velocity modeling for static and dynamic cases–Lift factors calculated in a vertical plane under the eccentric drill pipe.

This hole cleaning model is different from other published models in that it exclusively deals with the area lying immediately below the eccentric drill pipe. This specific annular cross-sectional area is chosen because this is where cuttings bed accumulation begins to occur.

In this model, the position of the drill pipe while rotating in the eccentric annulus is the greatest unknown. A particular level of drill pipe eccentricity () is input to cover those situations when the rotating drill string is lifted off bottom. Further complicating things, in a skewed annulus, there are an infinite number of eccentricities at a given angle of deviation. For the high angle situations where the drill string is being rotated, a drill pipe eccentricity level 0.5 is often used.

In this model, operational activities that can promote increased hole cleaning on a temporary basis are not taken into account. These activities can include:–Frequency and duration of trips–Application of backreaming–Application of viscous/non-viscous or weighted sweeps–Increased circulation times–Limits on penetration rates

This model is purposely constructed to characterize hole cleaning efficiency on a steady-state basis where the hole is being drilled in a rotary (eg, non-sliding) mode.

After its development, the model was tested in a number of drilling situations to ensure it was a valid working tool. As part of the validation process, data from Statoil's well Statfjord C-02, a previous world-record ERD well for horizontal displacement, was analyzed according to this model. Concepts learned from this in-depth investigation were then later applied on another Statoil ERD well, Sleipner A-2.

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The Dual Density Riser Solution
Authors: Lopes Clovis A. , Bourgoyne Adam T.
Published: December 2007

The objectives of this project are to determine the advantages, disadvantages, technical feasibility and economic feasibility of the use of gas lift in a marine riser to maintain the pressure in a subsea wellhead equal to the hydrostatic pressure of the seawater outside of the wellhead. Such a dual density system for drilling in deep water would have one effective fluid gradient between the surface and the seafloor and another fluid gradient within the subsea well. This would in effect reduce the casing design problem to that of an equivalent on-shore well. This paper gives a summary of our progress to date.
Replacing 5 Inch and 3-1/2 Inch Drill Pipe With a Single String of 4 Inch Drill Pipe
Authors: Mehra Sachin , Smith J. E.
Published: December 2007

Sedco Forex is drilling horizontal and extended reach holes with their Simpler Rig 101 in the Rabi field in Gabon, West Africa. The typical drilling programs call for 17-1/2 in., 12-1/4 in., 8-1/2 in. and 6-1/8 in. bit diameters. Casing sizes are 13-3/8 in., 9-5/8 in. and 7 or 7-5/8 in.. This normally requires the use of two different pipe sizes: 5 in. and 3-1/2 in. The 5 in. pipe is used to drill down to the 6-1/8 in. section because of its torsional strength and fluid carrying capabilities and the 3-1/2 in. pipe is used to complete the hole because the tool joints on the 5 in. pipe are too large for the 6-1/8 in. hole.

A single string of 4 in. drill pipe with double shoulder tool joints can replace the 5 in. and 3-1/2 in. pipe. The 4 in. pipe has the torsional strength and fluid flow capacity needed for the upper portion of the hole, it has better buckling strength than the 3-1/2 in. pipe for more weight on the bit and the tool joints will fit in the lower portion of the hole.
Field Recovery of High Holding Capacity Anchors in 5,000 Feet of Water
Authors: Towns T. K. , Christman S. A. , Ettle R. E. , Bruce P.
Published: December 2007

This paper will review the engineering design and field procedure for recovery of high holding capacity anchors on a moored drilling vessel in 5,000 feet of water.

It will discuss the variables that field personnel can control at the surface and how changing these variables affects forces applied to anchors embedded into a silty-clay bottom. The paper will show how to estimate the resultant force applied to the anchor since there is currently no method available to measure forces at the anchor. The paper will include a discussion of the upgrades to the chain chaser system and a large 450 MT winch used on one anchor handling vessel.

This paper will show how to balance line tensions between the winches on a moored drilling vessel and an anchor handling vessel so that the upward resultant force at the embedded anchor is effectively applied. The pulling procedure can result in lower chase wire tensions at the stern of the anchor handling vessel while reducing the time necessary to recover an embedded anchor. Lower wire tensions increase the factor of safety for the components that make up the chain chaser system and reduce the risk of a failure.

As operators move to deeper waters using moored drilling vessels, thorough understanding of the forces being applied to the chain chaser and anchor can improve recovery of high holding capacity anchors and minimize recovery time. This new technology can help moored drilling vessels operate efficiently in deep water.
PELAUT—A Purpose-Built Semisubmersible Drilling Tender
Authors: Manning F. T. , Pauling J. R.
Published: December 2007

We describe the design, construction and operational experience with the industry's first purpose built semisubmersible drilling tender. In 1987, the Petrodril Company perceived the need for a drilling tender having better wave response characteristics than the barge type derrick vessels used previously. Their need was for a vessel to carry out well servicing operations on platforms installed in water depths of 40 to 400 feet on the north coast of Brunei. Operational capability in seas of up to 20 feet significant height would be a major requirement for the new vessel in order to reduce weather downtime to virtually zero.

The capability for transporting the derrick equipment set (DES) on board and a transfer to or from vessel to well platform in eight lifts was a requirement. This is accomplished by two rotating cranes of 150 and 37 tons capacity respectively. Variable load capacity of 2300 tons for tubulars, consumables and the DES is provided.

The resulting twin hull semisubmersible design was optimized to achieve minimum wave induced motions while maintaining target values of stability, working area and load capacity. Both state of the art computations and model testing were utilized in arriving at a vessel that could achieve these goals.

Construction commenced in March 1993 with delivery in March 1994. Now after two full years of operation, the seakeeping performance has exceeded expectations.
An Overview of Air/Gas/Foam Drilling in Brazil
Authors: Negrão A. F. , Lage A. C. V. M.
Published: December 2007

The air. gas and foam drilling has been used in specific areas in Brazil as an alternative for problems caused by the traditional drilling process. Considering those two-phase flow drilling operations, this work focuses on their benefits and operational improvements. Furthermore, the comparison between the performance of conventional and two-phase flow drilling has been showing this new technique has some advantages: (1) minimum or no damage to sensitive pay zones. (2) immediate and continuous evaluation of cuttings for hydrocarbon shows, (3) avoidance of lost circulation, and (4) higher penetration rates in hard formations.

Two very recent on-shore two-phase flow drilling field cases, one with joint pipe connections, and the other with coil tubing are mainly described. Their results arc analyzed concerning the surface equipment design, appropriate technique for connections when using drill pipe underbalanced drilling, as well as the comparison of predictions of computer programs to real field data.

Future plans for the continuity of the two-phase flow drilling operations in Brazil arc also commented Additionally, potential areas and concrete actions for improving operational feasibility of this emerging technology are identified. The target is a safer and economical air. gas or foam drilling operation.
Stochastic Mapping of Lithology in a Carbonate Reservoir
Authors: Sahin A. , Ghori S.G.
Published: December 2007

Stochastic maps of reservoir lithology are extremely useful for planning during field development, production and management. Moreover, lithology types may have significant controls over porosity and permeability distributions within the reservoir. Therefore, the stochastic mapping of lithology may be considered to he the first step in geostatistical modeling of porosity and permeability distributions during reservoir characterization.

Several stochastic mapping (i.e. conditional simulation) techniques have been developed in recent years to generate equally-probable, multiple realizations of reservoir lithology. Bach realization constitutes a high resolution stochastic image, or map, displaying a realistic level of heterogeneity. It also reproduces the histogram and the spatial pattern of the actual data besides honoring these data at all sample locations.

In this study, the Sequential Indicator Simulation (SIS) technique was employed to generate stochastic maps in a carbonate reservoir consisting of three lithology types (dolomite, limestone and anhydrite). The basic data consisted of lithology indicators representing these lithology types and were derived using several techniques. The simulation provided a total of twenty realizations indicating the presence or absence of one of the three lithologies within cells each having 300m × 300m × 0.5ft dimensions. The results indicate an excellent match between the histogram of the input data and that of the simulated values. Comparison of lithology maps derived from simulation with those of the corresponding well-log porosity fields indicates that porosity does not correlate well with lithology except locally with anhydrite lenses. This is explained by the gradual change of well-log porosity values across lithologic boundaries observed in the input data.

Introduction

Lithologic maps and/or cross-sectional plots of lithology are extremely useful tools for planning purposes during the entire lifetime of oil field projects, particularly for field development, production and management. Classical deterministic or geological maps are generally smooth and do not reveal a realistic level of heterogeneity. Therefore, stochastic mapping or conditional simulation techniques have been employed in recent years to provide stochastic maps of lithology. Stochastic mapping of lithology has also been proposed as the first step in modeling petrophysical properties such as porosity and permeability whenever the lithology types have significant control on distribution of these variables.

Stochastic mapping techniques provide equally-probable, multiple realizations of lithology distribution within the reservoir. P. 183^
POSC and the Emerging E&P Business Perspective
Authors: Ring M.J.
Published: December 2007

Adoption of standards in today's business ecology is a strategic decision; most organizations have either embraced them or they will. The strategic need for oil and gas industry standards particularly in the area of integration of business processes and information sharing was the implicit underpinning of the formation of Petrotechnical Open Software Corporation (POSC) in 1990. The business drivers are low oil prices, increasing costs, lower margins, and increasing risks. The oil industry responded by focusing on core business assets, consolidation and restructuring, implementing risk management, increased collaboration with partners, increasing productivity, reducing costs, improving reservoir performance, and a move towards a global business (1).

The use of standards allows for the sharing of data and information across disciplines, functions, companies, countries, partners, through the life cycle of an asset (Figure 1) so that collaborative groups can focus on concurrent, interactive creative thinking and stakeholders can access and respond to pertinent information in real time (Figure 2). Industry standards will imiprove the flow and quality of information throughout an E&P organization; reduce the time, cost and risk of Information Technology solutions; enable new business practices within oil companies and new relationships between suppliers and consumers.

Standards allow better decisions due to improved information resulting from better access to complete data and dramatic improvement in bottom line results (improved work practices, reduce cost and time). Cost savings of 25% are targeted; time savings of 40% have been noted. Improved margins (£/BOE) are being realized by simultaneously decreasing costs (£) and increasing value (BOE).

Industry achievements to date have been significant: drastic cost reductions, outsourcing, partnerships, new team sharing behaviour, new technologies, and the use of de facto standards. But it is recognized that this is not enough; the industry needs to find new ways of working that can reduce costs further and sustain new growth. There are numerous evolving paradigm shifts in the oil and gas industry (Table A). Significant changes are occurring in technology, sociology, geopolitics, business processes, decision processes. Organisations are redefining themselves as the business ecology evolves into the knowledge era.

Knowledge Paradigm in the Oil and Gas Industry

The E&P industry is based on communications of knowledge between people, teams, organizations, etc. Consider the value placed within each organization for the "oil finders"; the drilling team who are able to achieve both the technical and business objectives of the well; the reservoir management team who can optimize reservoir performance or "squeeze the oil from the ground"; the operations team with no injuries; etc. All these teams are characterized by possessing a common shared knowledge which stimulates interactive mental creativity and innovation.
Environmental Cost Criteria for Exploration & Production
Authors: Parums A. M. , O'Leary H. E.
Published: December 2007

BP Exploration (BPX) has completed a study which assembles in a rigorous, comparable format, a wide range of quoted costs for reducing emissions and discharges to the environment. It compares the costs of different improvement technologies for Exploration and Production, and shows how these costs compare with other parts of the petroleum sector or other industries. The study uses two measures (‘capex/annual te’, ‘NPC/total te). Regulators’ expectations of justifiable spends are mapped onto these typical technology costs from studies and actual projects. The environmental issues considered include atmospheric emissions (VOC, methane, NOx and CO2) hydrocarbon aqueous emissions.

These common measures can be used by drilling, petroleum, facilities and production engineers to benchmark environmental spend and by management as an input to decision making in response to environmental challenges.

The simple framework enables the mapping of environmental assessments from a variety of sources enabling site specifics decisions to be considered against a company-wide or industry-wide context.

As well as providing a framework for true economic comparison of environmental improvement options, the paper provides powerful support to the strategy of making simple operational improvements before costly facility change, and for the need to consider the whole scope of environmental impact from any project, not just one narrow goal.
A Mathematical Model for Predicting Wellbore Screenout in FRACPACKs
Authors: Omari Mazen H.
Published: December 2007

The fracturing and gravel packing sand control technique, most commonly referred to as FRACPACK, has recently become one of the most successful and reliable ways to complete low to moderate permeability unconsolidated sandstone reservoirs. In addition to providing a good sand control completion, FRACPACK offers the advantage of stimulating the reservoir and reducing the final skin. FRACPACK treatments are most commonly done with the screen in place where a gravel pack packer is run with the blank pipe and screens placed across the zone of interest. Later, a fracturing treatment is performed through the gravel pack packer and across the screens (Fig. 1)

Although a lot of research has been made in the fracturing area of FRACPACKs, little is known about the nature of slurry flow in the screen/casing annulus below the gravel pack packer crossover ports and before entering the perforations. It is believed that as pumping progresses, deposition of proppant on the screen yields stable nodes that may cause bridging in the annulus that may result in early termination of the fracturing treatment.

This paper discusses the steps involved in mathematically predicting node buildup on the screen during FRACPACK treatments. A simple model was developed that calculates the size of the node deposit at the end of fracturing treatments based upon treatment parameters. FRACPACK case histories from the Gulf of Mexico where wellbore screenouts occurred were predicted by the model.
Development Of An Integrated Reservoir Characterization And Simulation Model For A Heterogeneous Carbonate Reservoir, Arab-D Reservoir, East Flank Of Ghawar Field
Authors: Valle A. , Faulhaber J.J. , Keith T.H. , Hsueh P.T.
Published: December 2007

Three dimensional geocellular and simulation models were developed for an area on the eastern flank of the Ghawar Field in the Arab-D carbonate reservoir that displays anomalous flood front advance and the potential for by-passed oil. Results were achieved through the integration of openhole log data, well performance data, production log data, well test and pressure build up data, core descriptions, 3-D seismic structure, and 3-D seismic influenced permeability distributions. The final products were simulation and geocellular models that were consistent with each other and with all of the available engineering and geologic data. This approach has constrained the resulting models towards a more unique solution that can now be used with greater confidence for reservoir management and the identification of areas of lagging flood front or bypassed oil.

This study was built upon a previous study which showed considerable success through innovations in model layer selection, mapping of very high permeability areas, horizontal and vertical permeability distribution, grid size and relative permeability assignments. However, the incorporation of other data sets, particularly newly acquired 3-D seismic, demonstrated that the predicted distribution of by-passed oil is dependent upon an accurate description of structure, faults and related fractures as well as rock porosity and permeability. The fully integrated modeling approach utilized here was recognized as a superior way to develop a useful simulation model.

This project was accomplished through a multidisciplinary team approach. The team varied in size and membership as the project developed through its various phases. This project integrated the work of reservoir engineers, reservoir simulation engineers, petrographers, geologists, geophysicists, petrophysicists, and geocellular modelers.

Introduction

This paper discusses the development of an integrated reservoir characterization and simulation model for a very heterogeneous segment of the Arab-D carbonate reservoir of the Ghawar Field in Saudi Arabia. The referenced reservoir segment is roughly 15 km wide by 15 km long and is being depleted by peripheral water injection. Waterflood advance in this area of the reservoir has been extremely rapid. There is therefore the potential of losing oil reserves due to by-passed oil (Fig. 1).

Moore discussed reservoir management issues, well completions and production strategies for this area of Ghawar. In his paper, Moore correlated the fast flood front advance to the preponderance of superpermeability (layers which generally exhibit specific flow rates of 500 BPD per foot or greater). He ascribed the main source of this superpermeability in this part of the reservoir to vugs created after the stick-like organism, Cladocoropsis was leached out from a cased-hardened dolomitized rock at the middle of the reservoir, Zone-2B (Fig. 2).

P. 195^
Production Water Management in Oman
Authors: Al-Muscati A. , Huijskes J. , Parker D.H.
Published: December 2007

This paper describes the development of the Production Water Management Plan for Petroleum Development Oman (PDO) and its subsequent implementation. It outlines the current water production and disposal practices, the existing Omani legislation on waste water disposal, and trials carried out by PDO, all of which resulted in the development of the plan and an implementation strategy agreed by PDO and the Government to achieve a produced water management operation that is sound both in environmental principle and practice.

Introduction

PDO currently produces some 330,000 m3/day of water as a by-product of its oil output of about 135,000 m3/day. The volume of this production water has been steadily increasing over time and is predicted to rise to about 650,000 m3/day by the year 2005.

The disposal of large volumes of production water presents PDO with important environmental and economical challenges. In order to manage these challenges, the PDO Production Water Management Plan was developed and agreed with the Government and private shareholders.

In resolving the best technical solution for disposal at any of PDO's production sites, PDO has fully evaluated the principles of the PDO Production Water Management Plan by testing and then implementing the latest state-of-the-art technologies. Studies and trials have been carried out in order to achieve improved cleanliness of production water, and to identify economically attractive usage alternatives for the water. In particular field trials to test various deoiling equipment have been carried out, as well as a detailed study and field trial into the use of disposal water as irrigation water for an agricultural project. As a pre-study for the agricultural conceptual work, other alternative water disposal methods, such as the use of evaporation ponds, ocean discharge and production of potable water, were evaluated but found to be economically less attractive than the agricultural alternative.

Having completed these trials and studies, plans have been put in place to bring production water disposal in all production centres into line with the principles of the Production Water Management Plan. The main outcome has been the implementation of Deep Water Disposal for most production centres in the South of Oman.

Water Production

The disposal of large volumes of production water presents PDO with an environmental and water resources conservation issue of considerable importance, in terms of both quality and overall quantity. The volume to dispose of is expected to rise over the next decade, with no significant increase in the volume of water that can be profitably utilised either for reservoir pressure maintenance or for other purposes.

High water production is caused by bottom or edge water drive, high oil viscosity and low density contrast. Well over half of PDO's Oil initially in Place (STOIIP) is in reservoirs with conditions resulting in high water production due to natural water drive.

P. 265^
Slim Hole Drilling In Kuwait (4 1/2" Hole Size)
Authors: Al-Khayyat Bader , Al-Azmi Bader
Published: December 2007

Slim Hole Drilling in Kuwait Oil Company (KOC) is not a procedure that is planned for in initial well designs. The complexity of drilling conditions in Kuwait has forced KOC to plan and drill such hole sizes as a contingency. First, one must appreciate the drilling conditions that forces the need for slim hole drilling in Kuwait. Highly fractured, extremely weak zones near surface and below or between several productive field horizons are followed by a pressure transition that ends with a salt/anhydrite section with porous layers interbedded, containing H2S gas and water. In order to control the fluid within such layer, mud weight, in excess of 19.0 ppg is required. Below this section is a slight pressure reversal which includes fractured carbonates. Due to such pressure differences between layers and the position of lost circulation layers within productive zones, numerous casing strings are required to isolate pay zones from weak zones, normally pressured zones from high pressured zones and weak zones from other normally pressured zones, to maintain circulation for drilling and well control. Kuwait Oil Company Deep well programs end with 5½" casing set on bottom which requires that the well starts with 42" conductor at surface and 30" as surface casing. Unanticipated hole conditions or well problems that require setting a casing string at an earlier depth than what was actually planned for in the well casing design, will result in slim hole drilling on bottom in order to reach the objective of the well. Often very little allowance is available for problems by the very nature of drilling conditions.

Slim hole drilling in Kuwait is drilled in a hostile environment. The slim hole sections are typically in deep, hot hole sections. This environment often finds high pore pressures virtually near frac strengths. The wells are often either flowing or losing mud. To make matters worse, H2S accompanies any influx or drill volume gas.

The paper will cite case histories of wells that have included 4½' slim hole sections at depths from 19300 to 20774' in EXW-1 and over long intervals of 15704 to 18683' in DW-01 and in mud weight ranges of 16.0 to 19.3 ppg. Slim hole sections have been drilled using downhole motors as well as with rotary drilling. The case histories will additionally describe the down hole tool selections used along with kick and lost circulation handling. Also, discussions will touch on side tracking and completion on DW-02 where the the original 4 1/2" hole was drilled from 12,620' to 13,800' with 16.0 ppg mud and was side tracked from 12,821' to 13,560’. At the end of the side tracking, 3 1/2" liner was run and cemented as the completion liner and 2.6" bit was run on 1 1/2" coil tubing to clean out inside the liner.
Environmental Excellence and Profitability in Asset-based Upstream Organisations
Authors: Parums A. M.
Published: December 2007

The rapid change away from "functional" E&P organisations towards "Asset-based" ones has helped deliver enormous improvements in upstream profitability via de-layering, cost transparency, team integration and alliancing with external providers.

Without these changes the upstream industry would not be facing the future with the self-confidence and growth aspirations which are evident worldwide, both in mature areas such as the North Sea and new regions such as the Caspian.

Prima facie, the decentralising and delayering which are vital to the success of a move to an Asset-based structure carry the risk that a company’s good intentions towards environmental practice will not be delivered in actual operations. However this paper, drawing heavily from BP Exploration’s experience over the past three years, argues that this need not be so. Indeed, provided some key principles are followed, there is real potential for higher environmental performance, largely through liberating the talents and energies of the workforce.
Improved Environmental Compliance And Planning For Oil Field Water Management Using The Latest Information Technology
Authors: Evans R.
Published: December 2007

Oil field water management is increasingly a critical factor with respect to environmental protection and profitability for both new and mature oil field developments. For new oil field developments the integration of water management with oil production planning is vital to avoid environmental damage and bottlenecks to production. For mature oil fields the harmonization of topsides and downhole water control is critical to extending their economic life and continued compliance with environmental regulations, The multidisciplinary and inter-departmental nature of oil field water management, combined with rapidly evolving technology and environmental regulations, makes effective planning and communication vital. An oil field water management system using the latest information technology is described which has the objective to improve design, operation, profitability and environmental compliance. A suite of computer programs, amalgamated by a relational database can be installed on the office network to improve inter-department communication and data accessibility. The software provides expert system step-by-step guidelines for water management through out the oil field life cycle. After existing information on the field is inputted into the database, deficiencies in the data-set are highlighted along with guidance to rectify the shortfalls. Once an adequate data-set is compiled, sub-routines investigate, for example, water compatibilities, reservoir souring, thermal fracturing, water injection and production rates, environmental regulations, water quality requirements, downhole water control and topsides process design. A water handling strategy for the oil field life-cycle is then defined.
Beyond Federal Emission Limits: Steps to Take
Authors: Christy Roger H.
Published: December 2007

The emission control requirements for stationary internal combustion engines in California are being set lower than current federal limits. These limits apply to engines as small as 50 horsepower. Other areas of the country could eventually follow this trend if attainment is not achieved or if air quality standards are tightened. Internal combustion engines can be ripe targets for further controls because of their high aggregate emissions. Problems can occur when the emissions limits are tightened. For instance, when certain districts initially adopted technology-forcing limits, other districts later referred to those levels as available before the technology was even implemented. Occasionally, the limits were so low as to force replacement of many of the engines with electric motors.

Both regulators and industiy must make crucial decisions several years prior to implementing regulations whether they apply to engines or other equipment. These include setting emission limits with only predictions and assumptions on the technology’s reliability and feasibility. Optimistic predictions of control technology performance could lead to significant compliance problems after start-up. On the other hand, ignoring the realities of technological advances could result in setting overly conservative limits. This may lead to the addition of more costly controls on other source types in order to meet total emission reduction goals.

This paper will discuss steps that industry and government should take when developing incrementally more restrictive regulations. These include determining a valid inventoiy of existing engines, predicting future horsepower requirements, determining the amount of power reduction that may occur, analyzing the effects from real-world operating conditions, evaluating both unsubstantiated claims of performance and denials of progress, determining the difference between currently available technology and an arbitrary limit, calculating a realistic incremental cost effectiveness, and finally developing justifiable compliance alternatives.
A Reservoir-Level Approach to Evaluating Cost-Effectiveness of Environmental Regulations on the Natural Gas Exploration and Production Industry
Authors: Smith G. E. , Godec M. L.
Published: December 2007

Industry sources are pushing regulators to perform better cost- benefit analyses of the requirements they promulgate. While it is important to achieve greater balance between the costs and benefits of potential environmental compliance requirements, transparent, comprehensive analysis and comparison of costs and benefits has traditionally been difficult to implement and credibly defend. One alternative approach sometimes used by regulators is to compare the cost-effectiveness of various alternatives ($ per ton of pollutant removed). These calculations are often performed at a very aggregate level, and fail to take into account the site-specific diversity that characterizes the exploration and production (E&P) industry.

A reservoir-based approach can provide a more effective and accurate means of evaluating cost-effectiveness of alternative regulatory approaches, and ultimately, better cost- benefit analysis. Each reservoir can be uniquely characterized by its site-specific environmental and operating conditions to evaluate the application of a requirement in that location. An Environmental Module (EM) being developed for the U.S. Department of Energy (DOE) takes a first step toward building this reservoir level analytical capability for the impact and cost-effectiveness of environmental regulations on natural gas E&P.

This paper describes a reservoir-level approach to cost- effectiveness and cost-benefit analysis that accounts for the site-specific impacts of explicit control technologies. An example of cost-effectiveness calculations for potential regulatory requirements for control of hazardous air pollutants from E&P is provided. The possible benefits of using this approach are discussed.
A Fully-Implicit Thermal Reservoir Simulator
Authors: Naccache P.F.
Published: December 2007

This paper describes a 3D thermal reservoir simulator that models the injection of steam into heavy oil. The variables are pressure, energy and molar densities, and the equations are volume balance and component and energy conservation. The use of energy and molar densities means that there is no variable-switching, and the formulation combines the advantages of volume balance with a fully-implicit code.

A number of example problems are presented, including a large full-field fine-grid model run on parallel processors.

Introduction

We describe a full-featured thermal simulator that works in a number of coordinate systems: cartesian or radial, rectangular or corner-point geometry, and PEBI grids. It calculates non-neighbor connections, and will solve both single- and dual-porosity models. Local grid refinements can be defined, and these are treated simultaneously and fully coupled in the linear solver. A nine-point method can be used to reduce grid orientation effects. Computer memory requirements are minimized by only storing properties and derivatives for active cells.

The new simulator is based on an existing simulator that runs in either compositional or black oil mode. A choice has been maintained and we can either model dead or live oil. We define live oil as having at least one volatile component and dead oil as having none. This paper will describe the general formulation then give examples for the dead oil case. In practice, the dead oil model can be applied to oils that have a small proportion of volatile components as long as these components do not have a significant effect on the simulation.

To solve the thermal effects in the reservoir we choose energy rather than temperature as our new variable. The main advantage of an energy variable is that we avoid the problems of variable switching. In the dead-oil case, for instance, we can use energy to describe the boiling of water at a constant pressure and temperature. By adding an energy variable and an energy conservation equation to the existing formulation, we can simulate the injection of steam or hot or cold water (or hot or cold gas) into the reservoir. The formulation differs from many others in calculating energy bounds for each state in each grid block. The energy in the grid block then defines its state and a flash is performed within that state. We use a conventional fully-implicit discretization of the flow equations. Once the non-linear equations have been set up, they are iterated using Newton's method. The linear equations are solved using nested factorization. The simulator can be run either in scalar or parallel mode, and results are presented for both cases.