bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surge and Swab Modeling for Dynamic Pressures and Safe Trip Velocities
Authors: Lal Manohar 
Published: December 2007

Abstract
Surge and swab pressures, which could cause lost circulation or gas kicks and blowout, result from running or pulling a pipe in a borehole. Recent downhole measurements indicate that these pressures differ considerably from the pressures anticipated by traditional computational models which compute such pressures on the basis of steady state flow.
In this paper, a new dynamic surge and swab model is presented that is based on the physics of the transient nature of the phenomenon. It treats friction as a distributed parameter and considers various parameters in hole geometry, hole expansion, varying trip velocity, return area for tricone and diamond drill bits, plugged jets, and the mud properties. The computer program for the model not only predicts the maximum surge and swab pressures or their variation with time at various points in the borehole, but also computes the safe maximum trip speed for a specified pressure margin. Computer studies for running a casing, liner, and drill string in several actual wells show the model to have fast computer run times. The results of some of these studies are reported in the paper. The program is both interactive and user-friendly, and is a significant improvement over the existing models.
An Experimental Analysis of Vertical Two-Phase Flow Using a Drilling Mud/Natural Gas Medium
Authors: White J. P. 
Published: December 2007

Abstract
Engineers and scientists are interested in predicting the behavior of fluids flowing in a pipe. Much effort has been directed toward the study of both single-phase (liquid or gas) and two-phase (liquid and gas) flow. This report describes an experimental study of two-phase flow up a vertical pipe using non-Newtonian liquids. A mathematical correlation of the data generated by using various fluids under a relatively wide range of flow conditions yields two equations that predict two variables of interest-the friction pressure gradient and the flowing fraction of liquid in the pipe.
What Happened to the Daywork Contract
Authors: Langston J. V. 
Published: December 2007

Abstract
This paper develops the historical roles of the Drilling Contractor and the Operator by categorizing land wells into areas of difficulty and risks. The first area is composed of shallow wells that are suitable for footage drilling. The second group contains wells, usually medium depth, with some risk and hole problems. The third category includes the high risk, deep wells with high pore pressure and protection casing.
The story behind these categories demonstrates what happened before and during the five boom years of 1977 – 1981. The Operators began to supplement their in-house expertise with consultants. These consultants ran the capability range from excellent to unsatisfactory. The recent high cost of drilling has been attributed to less than perfect planning and execution of those plans stacked on increased costs.
Since January, 1982, the role of footage drilling has been restored in the first category wells. In category 2 wells, the daywork contracts have been replaced by footage and turnkeys to total depth. In the 3rd category, the footage and turnkeys have been extended through landing and cementing the protection casing after penetrating abnormal pressure. It appears that the Operators have traded one consultant for another, the Drilling Contractor.
This paper develops that long term, the responsible Operator will self insure on the high risk wells by drilling daywork. The responsible, surviving Contractor will have to be paid for trouble on each well that can range from 10 to above 30 percent. To the Contractor, it's one contract risk that must be covered long term on every well. Even though the footage and turnkeys have the cosmetic appeal of improving the Drilling Contractor's motivation, the self insured day rate contract is expected to prevail with the Operators who drilled numerous wells. The exception will be operation where footage and turnkeys will be useful to establish a firm price.
A Production and Operation Review of the Khurais Gas Lift Project
Authors: Chornoboy G. M. , Engelhardt H. W. 
Published: December 2007

ABSTRACT
For development of the Khurais field, gas lift was selected for its inherent flexibility and applicability to high flow rate wells. After one year of operations, the severe desert environment and oversized gas choke valves have proven to be major problems. The downhole equipment has mostly performed well and problems have been diagnosed using surface pressure recording charts. Most wells appear to be producing up to expectations but maximum flow rates have not been explored completely.
Seismic Lateral Prediction in Chalky Limestone Reservoirs Offshore Qatar
Authors: Rubbens I. B. H. M. , Murat R. C. , van Keulen J. 
Published: December 2007

ABSTRACT
Following the discovery of non-structurally trapped oil accumulations in Cretaceous chalky reservoirs on the northern flank of the North Dome offshore QATAR, a seismic lateral prediction study was carried out for QATAR GENERAL PETROLEUM CORPORATION (Offshore Operations).
The objectives of this study were:
to assist in the appraisal of these oil accumulations by predicting their possible lateral extent; to investigate if the technique applied could be used as a basis for further exploration of similar oil prospects in the area.
Wireline logs of eight wells and some 1000 km of high quality seismic data were processed into acoustic impedance (A.I.) logs and seismic A.I. sections. Having obtained a satisfactory match of the A.I. well logs and the A.I. of the seismic traces at the well locations, relationships were established by the use of well log data which allowed the interpretation of the seismic A.I. in terms of reservoir quality.
Measurements of the relevant A.I. characteristics were then carried out by computer along all seismic lines and porosity distribution maps prepared for some of the reservoirs.
These maps, combined with detailed seismic depth contour maps at reservoir tops, lead to definition of good reservoir development areas downdip from poor reservoir quality zones i.e. of the stratigraphic trap areas, and drilling locations could thus be proposed.
The system remains to be adequately calibrated when core material becomes available in the area of study.
Operating an Onshore Sour Gas Field in Abu Dhabi
Authors: Morsi K. M. , Constantini N. M. 
Published: December 2007

ABSTRACT
There is considerable interest in producing deep high pressure reservoirs that contain substantial amounts of sour gas. As a result of the high pressure and sour production involved, it is necessary to incorporate high - strength tubular materials and safety features such as surface controlled sub-surface safety valves, downhole packers and chemical injection system into the completion design.
The use of such a completion concept requires larger hole sizes and heavier casing strings than have previously been used by other operators in the same area.
The experience gained from producing wells in such a gas reservoir is now being applied to the design and completion of wells in a new gas reservoir with a higher percentages of Hydrogen Sulphide and Carbon dioxide.
A Review of the Arun Field Gas Production/Cycling and LNG Export Project
Authors: Alford M. E. 
Published: December 2007

Abstract
The Arun field was discovered by Mobil Oil Indonesia Inc. in late 1971 in its Bee block in the Aceh province on the north coast of Sumatra, Indonesia. Mobil's operations in this area are conducted under the terms of a production sharing agreement with Pertamina, the Indonesian state-owned oil and gas enterprise.
The scope of operations covered by this paper is from production of gas and raw condensate in the field through stabilization and export of condensate and purification, liquefaction, and export of gas at the LNG plant at Blang Lancang, near Lho Seumawe (Sumatra) Indonesia.
Mobil Oil Indonesia, Inc. is the field operator and P.T. Arum NGL Company operates the pipelines and LNG plant facilities. All the facilities which will be described are owned by Pertamina; P.T. Arun is owned by Pertamina, Mobil Oil Indonesia, and Japan Indonesia LNG company (JILCO). JILCO represents the five (5) original Japanese LNG purchasers.
A Reservoir Optimization Study—El Bunduq Field, Abu Dhabi, Qatar
Authors: Bashbush J. L. , Savage W. K. , Nagai R. B. , Ogimoto Tadao , Wakamiya Jun , Takizawa Hiroo 
Published: December 2007

ABSTRACT
El Bunduq reservoir is located in the offshore area of Abu Dhabi and Qatar. The field was shut-in in July 1979 due to production with high gas-oil ratios. Pressure differences of 200-400 psi between the flanks and the central part of the reservoir were still present almost four years after the field was shut-in. A comprehensive reservoir engineering study determined that the reasons for this behavior were the deteriorating qualities of the reservoir rock downstructure and the presence of a tar mat around the field.
After the field behavior was history matched, model studies of a representative sector of the field indicated that peripheral waterflooding would recover less than 15 percent of the 00IP in a period of 30 years. However, pattern injection recoveries were calculated to be at least twice as high. Several full field alternatives were investigated to optimize the development of the reservoir under a pattern waterflood. This paper summarizes the various studies that led to the acceptance of the idea of pattern development over peripheral injection, as a result of the unique characteristics of this field.
Reservoir Performance Analysis of Arab "D" Zone (Bahrain Field)
Authors: Murty Challa R.K. , Fathalla Mohammed , Al-Mahroos Faisal M. 
Published: December 2007

ABSTRACT
This paper reviews the case history of a saturated oil reservoir for the past ten years and examines the EOR prospects. The reservoir is overlain by a thick gas cap and underlain by an active aquifer and thus producing by a combination of gas cap expansion and water drive with slight contribution by solution gas. Material balance calculations indicated that the water drive is becoming more active. However, the study suggested that the oil band has not migrated into the gas cap as yet. This is possibly due to the presence of less permeable shaly lime stringers in the reservoir. If the pressure decline continued causing enough pressure differential for these stringers to break down, the oil band may move into the gas cap and some of it may be lost as irreducible oil saturation.
To offset this, gas injection followed by recycling is found the most suitable method to recover the reserves efficiently. This process may find application in reservoirs of a similar nature wherever a sufficient gas source exists.
Increased Fracture Penetration and Productivity using Xanthan Gelled Acid in Massive Carbonate Formations
Authors: Molon J. -P. , Fox K. B. 
Published: December 2007

Abstract
A measurable improvement in productivity can be achieved using xanthan gelled acid to stimulate carbonate formations. Well productivity results were compared to conventional acid fracture treatments. The significant improvements over classical acid fracturing techniques are due to the improved control of acid leakoff rates, retarded reaction rate and improved fracture width maintenance.
The difficulties involved in acid fracturing massive Middle East carbonate formations are discussed and solutions are proposed using gelled acid technology. Some limitations in computer predictions of acid fracturing results are also discussed.
Effect of Polymer Adsorption on Mobility Ratio
Authors: Omar A. E. 
Published: December 2007

ABSTRACT
Several properties of two of the viscous polymer fluids used in reheological control were investigated. Polymer adsorption on the rock surfaces of porous sandstones and its effect on permeability of producing formation was studied.
A naturally occurring polymer, a Guar gum, was found greatly to reduce the permeability of the producing formation, although the use of a breaker solution was found to restore the permeability lost through polymer plugging. Use of appropriate breaker solution was found to reduce the loss permeability to only one or two per cent of the original value.
Adsorption of the synthetic polymer, acrylamide, was found to be directly related to the shaliness of the porous sand. Deactivation of polymer due to adsorption was found to be significant in formations having large surface areas. The results indicate that polymer loss eventually results in a water bank ahead of the polymer solution and thus greatly reduces the polymer's effectiveness in water-flooding.
Design of a Pilot Polymer Flood in the Marmul Field, Oman
Authors: Teeuw D. , Rond D. , Martin J. H. 
Published: December 2007

ABSTRACT
The Marmul heavy-oil field is located in South Oman in the province of Dhofar. The main sandstone reservoir consists of glacial deposits of Permo-Carboniferous age and contains about 2.5 billion barrels STOIIP of 21° API crude. The field is in the stage of primary development with a current production of 45000 BPD.
Oil production by depletion is expected to be low, while a water drive will be adversely affected by the high oil viscosity and high permeability. Thus the Marmul field offers ample scope for EOR techniques, for which two methods have been selected, viz. steam injection and polymer injection. In view of the long lead times involved early testing of these techniques is planned.
This paper deals with the design of the relevant polymer flood and pilot tests. A suitable mobility ratio is determined from calculated drive efficiencies and related polymer requirements, allowing for polymer retention and for viscosity grading of the polymer flood. In the selection of a candidate polymer, attention is paid to viscosifying power, retention characteristics, plugging tendency, shear stability, and last but not least maximum operational flexibility in the field. As for the latter, a liquid polymer seems preferable to a powder polymer.
Results of laboratory experiments indicate that polyacrylamide emulsion polymers provide attractive properties for application in Marmul. Retention in the highly permeable sands is low and so is the plugging tendency. However, viscoelastic effects cause very high pressure gradients at high flow rates, which may adversely affect polymer injectivity. This can be resolved by subjecting the solution to controlled shear treatment prior to injection.
Numerical simulations predict that the oil recovery is substantially enhanced by polymer injection. To have a qualitative Indication of the sweep efficiency improvement in the first (inverted five-spot) pilot test, it is proposed to have the polymer drive preceded by injection of a limited volume of water. The reversal in oil cut should then provide an indication of the better sweep.
New Techniques To Measure and Control Corrosion and Thermal Stability of Drilling Fluids in Deep Wells
Authors: Moussa M. M. 
Published: December 2007

ABSTRACT
Problems associated with geothermals and deep well drilling can be minimized by the proper choice and control of the drilling fluid formulation. High temperature gelation tendency of conventional muds has been avoided by employing the sepiolite (sea mud) systems. Several formulations are tested at elevated temperatures ranging from room temperature to 500°F. Also, the pH value, flow rate and pressure were changed to examine their effect on mud stability. The drilling operation is simulated in the laboratory by two flow loops.
The corrosion rate is measured under the above conditions by the weight loss technique. Three different corrosion cells were used in this study; each one is designed to suit a specific technique. Each cell is loaded with two flat coupons of mild steel (1018). The weight loss of the specimen before and after the run during a certain period of time is a measure of the corrosion rate. The corrosion rate is minimized by adjusting the pH value and the formulation of the fluid. Corrosion rates are measured using different techniques—the flow loop, rolling and static. A new mag-corrosion cell has been incorporated in the loop to combine the rotational motion and the linear flow of the fluids in the annulus. Different mud formulations have been tested.
Correlation between techniques under different conditions are included. The coupons in the flow loop experience change in temperature from room temperature to the test temperature in one cycle with about 15 cycles per hour in one run.
Corrosion is higher when using the mag-corrosion cell than when using the linear flow when both are exposed under the same conditions. Static technique rates are less than rolling. Critical pH values are determined for specific drilling fluids.
Minimizing Casing Corrosion in Kuwait Oil Fields
Authors: Agiza M. N. , Awar S. A. 
Published: December 2007

Abstract
Corrosion in production strings is a well known problem in Kuwait oil fields. Failure to remedy the affected wells results mainly in (1) undesirable dump flooding of the oil reservoirs, (2) or oil seepage and hydrocarbon contamination in shallow water bearing strata. Any of these situations (unless properly handled) leads to a disastrous waste of oil resources. This study discusses (i) casing leaks in Kuwait oil fields, (ii) the nature of the formations opposite the leaks and their contained fluids and (iii) the field measures that can be adopted in order to avoid casing leak problems.
A Case History–Fracturing the Morrow in Southern Blaine and Western Canadian Counties, Oklahoma
Authors: Craddock D. L. , Goza B. T. , Bishop J. C. 
Published: December 2007

ABSTRACT
This paper presents a case history of recent hydraulic fracturing treatments of the Morrow formation in southern Blaine and western Canadian counties of Oklahoma. Hydraulic stimulation has often been avoided in the past because of water-sensitive clays commonly found in the Morrow formation. However, recent field results by Sun show that the Morrow in this area can be successfully and profitably fractured. Included is a history of Morrow treatments in the area, a summarization of recent treatment techniques and their results. Also, an economic analysis of these results is included using two years of actual post-frac production history.
Proper Operation of Pumping Units Reduce Lifting Costs
Authors: Moriarty D. G. , Renard D. P. 
Published: December 2007

ABSTRACT
The pumping unit is a significant investment and essential to the life of a producing oil well. A proper inspection and maintenance program will prolong the life of the unit and reduce production costs. Leamco Services, Inc. successfully uses the discussed simple field inspection techniques to maintain pumping units in proper working condition.
Surface Integral Schemes for Fluid Flow and Induced Stresses Around Fractures in Underground Reservoirs
Authors: Cleary M. P. , Crockett A. R. , Martinez J. I. , Narendran V. M. , Slutsky S. 
Published: December 2007

abstract
The character of fluid flow in and around wellbores, cavities, and fractures in para-elastic media can significantly affect resource extraction operations in underground reservoirs. Reasonable estimations of hydraulic fracture profiles and propagation rates cannot be made without considering fluid exchange, especially for high leak-off; well production rates greatly depend on the flow rates into fractures; and reservoir properties are often strongly stress-sensitive.
In this paper, the fluid loss and the subsequent "backs tress" (i. e. induced reservoir stress) caused by it are characterized for stationary and propagating fractures, and the model is applied to three cases:
a single fluid in the reservoir and fracture; two fluids: a reservoir fluid and a fracture fluid that has penetrated some distance into the reservoir; a production model where the crack has been propped and the reservoir fluid flows out of the well.
The fluid exchange between fracture and reservoir is found by solving an integral representation of the flow in the reservoir. Since the pressure distribution in the reservoir is governed by a diffusion process, the flow out of (or into) the fracture and the backstress are rather simply calculated by integrating along the fracture the influcence function for the pressure due to each component of fluid exchange, specifying the pressure at each point on the fracture or closing the system by some other means such as solving simultaneously the flow equations in the fracture, and solving for the fluid exchange inside the integral. Then backs tress can then be found from the fluid exchange. Preliminary computational results for plane fractures have been obtained that compare well with existing special analytical and numerical solutions (e.g.,those of Cinco and Samaniego). More general results are provided for moving fractures and induced stresses, and the broader capabilities of the methodology are outlined.
A New Method for Determining the Rheology of Crosslinked Fracturing Fluids using Shear History Simulation
Authors: Craigie L. J. 
Published: December 2007

ABSTRACT
A new method which incorporates shear history simulation has been developed for measuring the rheological properties of crosslinked fracturing fluids. This proven method can provide the true rheology of the working fluid which enters the fracture. These data are essential when designing and conducting treatments in low-permeability formations, in order to obtain the desired fracture geometry.
Recent research has shown that the rheological properties of crosslinked gels are dependent on the method of preparation and testing. A single formulation of a fluid prepared by two different methods can have resulting viscosity profiles which differ by several hundred percent. The new method of measuring rheology overcomes many of the previous discrepancies resulting from preparation and testing by incorporating a shear history into the procedure. This shear history is similar to the tubular shear history a fluid experiences before it enters a fracture. The shear history apparatus is a capillary viscometer consisting of a series of tubes and additive pumps for the addition of crosslinkers. The length of the tubing as well as the pump rate can be adjusted to match laminar shear rates and shear histories encountered in fracturing treatments.
The paper describes a field scale-up model which verified the results of the laboratory tests.
Correlation of field data from bottom-hole tubing pressures on several fracture treatments further substantiates the validity of the laboratory apparatus. Results are presented which show that laboratory data can now be used to predict friction pressure exerted by fracturing fluids. Perhaps more important, though, is the insight now available into the true rheology of the fluid that enters the fracture and the development of techniques for controlling this rheology.