bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Foam Inhibitors at the Jusepin Oil/Gas Separation Plant, EI Furrial Field, Eastern Venezuela
Authors: Cassani F. , Ortega P. , Dávila A. , Rodriguez W. , Serrano J.
Published: December 2007

El Furrial reservoir is an important part of the new giant oil field recently discovered north of the Eastern Venezuela basin. Its medium gravity oil is processed at the large gas separation plant of Jusepin. Serious problems have occurred concerning the foam control and asphaltene depositions at the separators and oil/gas lines due to the crude oil carry-over containing abundant unstable asphaltenes.

This paper presents laboratory and field studies performed in order to evaluate the best commercial foam inhibitors as well as their optimum dosage to control such problems.

Laboratory results concluded that most of the commercial anti-foam agents are similar as inhibitors. Although there are certain differences concerning the "knockdown" effect. Its optimum dosage was found to be between 0.1 and 1 ppm related to the total processed crude. A clear relation between the crude oil asphaltene content and the foam stability has been established.

The best products were evaluated in the field and the results match quite well those obtained in the laboratory. The use of the best conventional chemical agents reduced deposition, oil carryover and increased the separator capacity. Further research is in progress to eliminate the oil carry-over to the gas lines and to avoid asphaltene deposition at the subsurface once the reservoir pressure reaches the critical deposition point.
Fractal Dimensions from Mercury Intrusion Capillary Tests
Authors: Angulo R. F. , Alvarado V. , Gonzalez H.
Published: December 2007

The fractal dimension (FD) of sedimentary rocks has become an important petrophysical parameter. The importance is partly because capillary presure (Pc) –and other transport coefficients— scale as power laws of fluid saturation. The scaling exponents are often related to the supporting media's FD. Water Pc, in particular, is known to scale as a power law of water saturation, in imbibition at low saturation of the wetting phase, and the scaling exponent is related to the FD of the pore-rock surface. Here we show results of mercury intrusion tests, in drainage at high capillary presure, which clearly show power law dependence between intrusion volume and Pc. We relate the scaling exponent to the pore bulk FD. We also report results of two dimensional image analysis which indicate that, in fact, both pore bulk and pore-rock interfaces are fractal.
Heavy Organic Deposition and Plugging of Wells (Analysis of Mexico's Experience)
Authors: Escobedo J. , Mansoori G. A.
Published: December 2007

The pipeline transportation of petroleum fluids can be significantly affected by flocculation, deposition, and plugging of asphaltene, paraffin/wax, and/or diamondoid in the transfer pipelines, tubulars, pumps, and other equipment. The economic implications of the problem of heavy organic depositions in such processes are tremendous.

In this report Mexico's experience with the pipeline plugging due to heavy organic deposition is reviewed and analysed based on the present state of knowledge. The modeling basis of a comprehensive estimation and prediction technique is presented. This technique is based on observed field and laboratory data, statistical mechanical theories, polydisperse polymer solution theory, continuous thermodynamics, electrokinetics and transport phenomena, colloidal solution theory, and the FRACTAL aggregation theory.
Synergistic Approach to Solve the Sand Production Problem in the Ceuta Field
Authors: Santarrosa C. E.
Published: December 2007

The Eocene C reservoir of the Ceuta field, in Western Venezuela is prone to produce sand, for this reason the totality of the wells have to produce upon chockes at rates below optinun level.

In an attemot to indentify why sand production ocurrs, a systematic study of the reservoir rock was carried out by integration of various core analysis data. The regional system of facies was determined and these facies were selectively tested on tri axial celds for stress determination. Log-derived rock mechan ical properties were also used to calculate critical flow rates at which the different facies will colapse, and consequently be produced.

It became clear from this approach that the Eocene C reservoir has to be selectively completed, avoiding the weakest facies, which in fact have poor hydrocarbon saturation and are characterized by having an interlaminar bed of illite that make them unstable.
New Experience with Electrical Submersible Pumps in Heavy Oil Crude
Authors: Bortolin L. , Uzcátegui E.
Published: December 2007

Optimization of lifting methods has been used in the oil industry to study both the oil well production and to determine a company's optimal investment policies.

The higher costs related with new facilities and artificial lift installations for new fields have created the necessity to review the latest technology available from different lifting methods, especially from the electrical submersible pump (ESP).

Few studies ‘rave been published in the area of heavy crude oil production optimization using ESP's as a lifting method. This paper describes the results of a project performed in two different fields and will study the performance of the equipment and the related aplication range. The equipment studied was installed in completions to depths ranging from 6000 to 11000 feet, with crude gravities on the order of 15 to 21 °API and bottomhole temperatures above 180 °F.

Some conclusions base shewn that the ESP equipment can perform in similar crudes with even lower °api's, despite a reduction in the pump's efficiency. Higher fluid production rates are also possible to achieve.

This survey and supporting data will confirm the submersible pump to be an alternative method for lifting heavy crude oil from relatively deep reservoirs.
Wafra Field Kuwait-Saudi Arabia Neutral Zone
Authors: Nelson Paul H.
Published: December 2007

The Wafra field lies in the western part of the Kuwait-Saudi Arabia Neutral Zone in the northeastern part of the Arabian Peninsula. The field was discovered in 1953 by the American Independent Oil Company and Pacific Western Oil Company on the basis of corehole and seismic information. It is unique in being operated jointly under separate concessions from two countries, Kuwait and Saudi Arabia, granted to American Independent Oil Company and Getty Oil Company (formerly Pacific Western Oil Company) respectively. It is northwest - southeast trending anticlinal fold, and produces from four main zones, two in the Eocene and two in the Cretaceous. produces from four main zones, two in the Eocene and two in the Cretaceous. Accumulated production to July 31, 1967 was 584,254,067 barrels of oil.

Introduction

The Wafra field is located in the west central part of the Kuwait- Saudi Arabia Neutral Zone, some 50 airline miles south and slightly west of Kuwait City, Kuwait. It is about 30 miles inland and the oil produced is moved by pipeline northeast 35 miles to Mena Abdulla (Aminoil) and 30 miles east and slightly north to Mena Saud (Getty), for processing and loading to tankers. (Fig. 1) Wafra field is unique in being in territory jointly owned by two separate countries, Kuwait and Saudi Arabia, and has been developed under two concessions by two companies, although at present most of the field operations are carried out by a Joint Operations Committee. It is also the only field on the southwest side of the Arabian Gulf producing from the Eocene, and although far from being of the caliber of its two giant neighbors, Burgan in Kuwait and Ghawar in Saudi Arabia, it has many interesting features. This paper is a brief description of the stratigraphy, structure, and production of the Wafra field.

HISTORY

The Neutral Zone between Kuwait and Saudi Arabia was established in late 1922, giving each country an undivided one half interest at a time when the only oil production in the region was some distance away in Iran. However, investigations in Kuwait to the north led to the discovery and early development of the great Burgan field in 1938–1940, and renewed development after World War II. This stimulated negotiations on the Neutral Zone which resulted in the awarding of a concession of the Kuwait one-half share of oil and gas to a group of American companies, called "Aminoil", in June 1948, and the Saudi Arabia portion to Pacific Western Oil Company (now Getty Oil Company) in January, 1949.

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Unexpected Near-Critical Reservoir Fluid Behavior in the North Monagas Oil Province, Venezuela
Authors: Rosales E. , Ashford F. , Parra E. , Parra D.
Published: December 2007

Corpoven, S. A. an operating Affiliate of Petroleos de Venezuela, S. A. has recently commenced production from a newly developed oil province located in the northern sector of the state of Monagas, eastern Venezuela.

Simulation of well stream phase behavior and production fluid pressure vs. temperature traverses in the CARITO 1-X well have indicated that some horizons defined as gas condensates produce fluids to the surface via the normal condensation process, while other sands also defined as condensates produce to the surface as a light oil or quasi-critical hydrocarbon liquid. Numerical evaluations have shown that the latter case occur at certain fluid transport rates via a progressive transition of the gas from the dense phase to the single phase liquid region. This flow responds to the flowing pressure vs. temperature relationship in the wellbore above the critical pressure and temperature of the fluid.

The identification and description of this anomalous behavior is very important to Corpoven's North Monagas operations because it allows for proper identification of CONDENSATE GAS RESERVOIR production. This classification receives special OPEC consideration under existing technical definitions. This paper deals with the reservoir fluid characterization procedures, simulation techniques, and phase equilibrium considerations required to properly identify the producing horizons in the CARIT0-1X well.
Differential Diagenesis of Reservoir Rock Related to Primary Sedimentary Environment
Authors: Muñoz N. G. , Yilalys J.
Published: December 2007

Detailed sedimentological analysis of 215’ of cores from the Misoa formation in well PB-691, Campo Benitez, resulted in establishing the paleoenvironmental sucession of the sequence, which includes four important reservoir levels known as B-6-X.A,B,C, and D.

Porosity and permeability values from core analysis, together with special petrologic studies with thin section petrography of sandstones, SEM, XRD, and Mineralog™ allowed us to know not only the mineralogical composition of the reservoir rocks, but mainly important information on the diagenetic process and which rocks were affected most.

This integrated study permitted a more comprehensive characterization of the reservoir rocks and their relationship with their primary environment of deposition, its hydraulic regime, and their final nature and behavior after the diagenesis.

In conclusion, it was found of fundamental importance to know the sedimentary environment of deposition of the sequence, since the diagenesis affected the reservoir rocks according to their original sedimentary conditions, so that identifying similar sequences by electrofacies in adjacent wells, their reservoir behaviour could also be correlated. Once tested this relationship within this field would open the possibility of using this method in other areas.

Similar core studies in wells LL-2929 and LL-3091 show this close relationship between primary sedimentary environment, differential diagenesis and quality reservoir rocks.
Onshore Drilling Operations In Abu Dhabi
Authors: Hollis John W.
Published: December 2007

The paper describes onshore drilling operations in the Sheikhdom of Abu Dhabi and the difficulties associated with operating in a difficult sand terrain.

Standardization of equipment and the adoption of unusual moving techniques have solved many of the transportation problems. Rigs car best be moved by overloading trucks with bulk units. Maintenance costs on the trucks are somewhat more than if the rigs were broken down into smaller loads but the time saved by using this method more than offsets the added expense of repairs.

Introduction

Abu Dhabi is the largest of the independent Sheikhdoms of the Trucial Coast with a land area of some 25,000 square miles and an estimated population of 30,000 inhabitants. The Abu Dhabi Petroleum Company operates population of 30,000 inhabitants. The Abu Dhabi Petroleum Company operates within a concession originally granted by the Ruler in 1939, which has a term of 75 years and covers rights in the land areas and territorial waters of the Sheikhdom. The Agreement was updated in 1965 with provision for periodic relinquishments. periodic relinquishments.
Acquisition and Application of Early-Life Well Performance Data
Authors: Porter D. A.
Published: December 2007

Simultaneous drilling and production operations, sometimes called producing while drilling (PWD) operations, can severely limit opportunities to acquire bottomhole pressure data. The additional risk and expense imposed by wireline operations upon PWD operations is often difficult to justify from an operational perspective. This paper reviews a simple technique and the equipment used to reduce that risk and expense.

Case histories demonstrate 1) the success of using this technique to acquire bottomhole pressure data in an operationally constrained environment and 2) the value of the early-life well performance data. It has proven to be a low-cost and reliable method of acquiring data with little to no risk to the completion. The data has been invaluable in providing an immediate evaluation of completion techniques, definition of reservoir performance and early reservoir depletion, calibration of flowing bottomhole pressure estimates, and a check as to the accuracy of surface recording equipment
New Spacers in Latin America
Authors: Labarca R. A. , Guabloche J. C.
Published: December 2007

The removal of drilling mud is a very important step for a successful primary cement job. Since cement is practically incompatible with drilling muds (a factor which causes gelation at the mud/cement interface and reduces displacement efficiency), spacer fluids are often used between the mud and cement; the proper selection of these fluids being a "must" A properly designed spacer fluid should maintain the drilling mud and cement slurry separated under the most severe conditions of the size of the hole to casing ratio; a spacer fluid has to be compatible with the drilling mud and the cement slurry to be used during cementing operations.

In response to these needs, a new Mud Removal Package – with a new group of spacers - has been introduced in Latin America since 1990. The fluids are mainly made of polymer blends, developed especially to be used with the Effective Laminar-Flow Technique and the Turbulent-Flow Technique. This article describes the two displacement techniques. It analyzes all the data obtained from compatibility tests with cements, muds and the new spacers. Two case histories are also included, as well as; a summary table containing data from field cementing jobs where these spacers have been used.
Development of Boomerang Hills Area of Bolivia
Authors: Graue D. J. , Larsen W. N. , Carazas M. , Gorriti M. , Guzman A.
Published: December 2007

An integrated study was carried out on the region of Bolivia called the Boomerang Hills. The purpose was to determine the oil and gas reserves and to design an integrated system which could produce the oil and gas. One goal of the design was to provide gas sufficient to meet the requirements of the contract between Brazil and Bolivia for delivery of gas.

The study integrated the disciplines of geophysics, geology, petrophysics, reservoir engineering, production engineering, and surface facilities design. Black oil simulation models were built, history matched, and used for predictions of four oil fields. A compositional model was built of one representative gas condensate field. The performances of dry gas reservoirs were predicted using traditional volumetric methods. The results of the study showed a total oil and condensate in place of 295 million barrels and a total gas in place of more than 1.8 TCF. The recoverable oil was estimated at 38 million barrels and the recoverable gas was estimated at 1.4 TCF.
GEOS - A Practical Tool for Reservoir Characterization
Authors: Parish R. G. , Wikramaratna R. , Craig P. S. , Seheult A H.
Published: December 2007

In this paper we describe the concepts behind the GEOS software system, a new reservoir characterisation product which is being developed to provide the user with the capability to interpolate data using geological inference, visualise the resultant characterisation in three dimensions and in colour and then to provide the data necessary for simulation of the fluid flow in the reservoir. The software is aimed at the reservoir engineer as well as at the geologist and petrophysicist, and it is intended to encourage a multi-disciplinary approach to reservoir management.
A Deep Hydraulic Fracture in Eastern Venezuela
Authors: Boggio C. , Blanco A. , Teggin D.
Published: December 2007

As part of the evaluation of a deep sandstone interval in eastern Venezuela, hydraulic fracture employing high strength proppant was used to determine the formation's flow potential. The interval fractured is at a depth of more than 16,000 feet and has a bottom hole static temperature of 288°F, conditions which require a good knowledge of reservoir and fluid properties. The design of this operation incorporated a number of data gathering steps to ensure that fracture geometry, in-situ stresses, and fracturing fluid behaviour were understood prior to executing the treatment.

Mechanical properties logs indicated that two separate fractures would develop at different pressures, the upper fracture initiating some 600 psi above the initiation pressure of the lower interval. The first pump-in test performed on the well consisted of a ball-out employing 600 balls transported in a linear gel frac fluid. Following this a temperature log was run across both intervals. The deflections indicated that two fractures had indeed been generated, both fractures coinciding well with the height predicted by the sonic log, although the upper fracture had grown some 50 feet higher than the prediction.

High temperature crosslinked water based gel was pumped as a minifrac without diverter (no ball sealers) at a rate of 18 bpm as the second downhole pumping test. This part of the operation was designed to determine actual fracture geometry, fracture gradient, and particularly the leakoff coefficient of this fluid.

The data on fracture height, fracture gradient, post-fracture pressure decline and fluid loss obtained from the logs and pump-in tests were incorporated into the design of the main fracture and the operation was successfully completed. The paper describes each of the pumping tests and shows how the test results and log derived data were used to verify the eventual design of the propped fracture.
Mechanical Fluid Loss Control Systems Used During Sand Control Operations
Authors: Restarick H. L.
Published: December 2007

The most common problem during the sand control operation is fluid loss. It is an inherent problem encountered worldwide, due to the high permeability of sandstone reservoirs which allows easy fluid flow into the formation matrix. Many wells which are candidates for sand control produce from marginal reservoirs and have insufficient bottomhole pressures to support a column of fluid in the wellbore. Still other wells with high pressure zones require high density completion fluids in order to balance the reservoir pressure during the gravel pack operation. In either case the positive pressure leads to fluid being lost to the reservoir. The result presents several potential problems: (1) formation damage caused by swelling of clay minerals within the formation, (2) formation damage due to particle invasion into the formation (3) formation damage due to dissolution of matrix cementation promoting migration of fines within the formation (4) flow channel blockage by precipitates caused by ionic interactions between well servicing fluids and formation fluids (5) interactions between well servicing fluids and formation fluids causing emulsion blocks, water block, or changes in wettability of a producing sand and (6) flow channel blockage due to viscous fluids creating a barrier in the near wellbore region. The need for mechanical fluid loss control systems in these situations is, therefore, obvious.
Formation Damage Due to Mineral Alteration and Wettability Changes During Hot Water and Steam Injection in Clay-Bearing Sandstone Reservoirs
Authors: Bennien D. B. , Thomas F. B. , Sheppard D. A.
Published: December 2007

Detailed laboratory studies were conducted to study the effect of hot water and steam injection on the permeability, relative permeability, wettability, residual oil saturation and mineralogie composition and structure of a clay bearing sandstone reservoir in Southern Alberta, Canada. The samples initially contained only kaolinite and illite clays, classically classified as non-water sensitive. This paper presents the results of three detailed laboratory coreflow experiments and documents the degree of formation damage (up to 95% reductions in permeability were observed) due to temperature induced mineralogie and wettability alterations. Multipoint temperature tests from 32 to 265°C (90 to 510°F) were conducted at full reservoir conditions on preserved core material to generate this data. The effect of steamflooding vs merely hot waterflooding at 265°C (510°F) on residual oil saturation is also illustrated indicating up to a 20% additional reduction in residual oil saturation by steamflooding. A complete suite of pre and post test perographie studies on each sample tested including x-ray diffraction, thin section and scanning electron microscope analysis indicate the definitive transformation of inert kaolinite day into water sensitive swelling smectitic day due to reactions between the kaolinite clay and the quartz during the high temperature flooding process. The results of this study have specific application to the design of hot water and steam injection projects in other similar types of sandstone reservoirs.
Determination of Stress-Strain Characteristics of Sand Packs Under Uniform Loads by the Use of Computer-Assisted Tomography and Finite Element Modeling
Authors: Kantzas Apostolus , Rothenburg Leo , Barrett S. V. L.
Published: December 2007

The local changes in the porosity of dry sand packs as a function of the imposed overburden were determined using Computer Assisted Tomography. Pressure cycles were imposed on sands of different characteristics and the porosity was measured at a resolution of 0.075 cm x 0.075 cm x 0.3 cm. Hysteresis in the porosity was observed. The imposed overburden and pore volume change were translated to stress and strain respectively. The local porosity changes depict the local strain under a given load. A two dimensional finite element model was developed to predict the microscopic behavior of sand. The model provided an excellent correlation between measured and calculated strains. The mean and standard deviation differed by 0.509 % and 0.35 % strain respectively, from the measured data. However, the model had difficulty in predicting dilation and extreme compression (5 to 6 % volumetric strain), it was also found that, in terms of elastic moduli, the model indicated that a macroscopically homogeneous sand is highly heterogeneous on the macroscopic scale. Under these conditions, local stresses varied sharply and stress components on an element tended to be non-hydrostatic.
Effects of Magnetic Interference on Directional Surveys in Horizontal Wells
Authors: Cheatham C. A. , Shih Symong , Churchwell D. L. , Woody J. M. , Rodney P. F.
Published: December 2007

The effects of axial magnetic interference on directional surveys using MWD tools in simulated horizontal wells was studied using full-scale laboratory tests. The results show that axial magnetic interference can cause large azimuth errors when the Standard Method of azimuth calculation is used in wells trending East or West. An alternative of calculating azimuth, the Short Collar Method, is shown to reduce errors in these type of wells by up to a factor of ten.
The Economics and Related Factors Involved in the Replacement of Land Drilling Rigs
Authors: Holm D. W.
Published: December 2007

The principal purpose of this paper is to evaluate the construction cost of a medium depth land rig made from all NEW components and the resulting effect on drilling contractor economics.

This evaluation will include an inventory of the proposed NEW rig, with a comparison of the costs of a similar rig built in 1981 - 1982, and a similar rig built from existing UNUSED equipment in manufacturer's current inventory.

The paper discusses the problems encountered in obtaining quotations for NEW equipment from manufacturers, the current attitudes of equipment manufacturers, the potential for problems from the use of existing UNUSED equipment in manufacturers inventory, and finally the possible effect on the day rates needed to justify the construction of NEW land rigs.

Probable reasons for the attitudes of the manufacturing industry and alternatives for the drilling contractor will be reviewed.

The paper concludes with the potential outcome of the current industry situation and general recommended strategies for industry management.
A Method for "Comparing Apples to Oranges" in Rig Bid Analysis
Authors: Lewis S. K.
Published: December 2007

This is a method which quantifies and documents rig bid analysis. The complexity of the drilling program is evaluated to produce a prioritized and quantified set of specifications. Rig data and contractor information are put into a standardized format and evaluated. This yields a numerical rating of each rig relative to the drilling program specifications. Each rig rating is applied to its bid cost to produce an expected well cost. The rig with the lowest well cost is the most economically justifiable.
PDC Bit Dynamics
Authors: Langeveld C. J.
Published: December 2007

The poor performance of PDC bits in harder formations is caused by downhole vibrations. However, proper operating conditions (i.e. low rotary speed and high weight on bit) and new technology for vibration control (anti-whirl PDC bits and a soft-torque rotary system) can successfully extend the application of PDC bits to harder formations. This conclusion is based on numerical modelling of PDC bit/drillstring assemblies and is supported by recent developments in PDC bit technology and torsional vibration control systems. The PDC bit model is fully dynamic and three-dimensional and is used to simulate normal rotary drilling. Sensitivity analyses of different PDC bit designs show bit-induced torsional, axial and lateral vibrations. Moreover, these analyses show that conventional PDC bits tend to whirl backward, resulting in reduced penetration rates and bit life. Antiwhirl PDC bits effectively reduce this tendency when run under the proper operating conditions of low rotary speed and high weight on bit.
Flow-Rate Predictions for Cleaning Deviated Wells
Authors: Luo Yuejin , Bern P. A. , Chambers B. D.
Published: December 2007

A new physically based model is described in this paper which has been developed based on the analysis of forces acting on the cuttings and the associated dimensionless groups. The model can be used to predict the critical (minimum) flow rate (CFR) required to remove, or prevent the formation of, stationary cuttings beds on the low-side of the wellbore in deviated wells. The model has been validated with the experimental data obtained from an 8″ wellbore simulator located at BP Research Centre Sunbury, and with field data from 8-1/2″, 12-1/4″ and 17-1/2″ holes.

By using the model, the effects of major drilling variables on cuttings transport are evaluated and compared with experimental and actual field data. The results show that the model accurately predicts the effects of the major variables such as: hole angle, penetration rate, mud properties and flow regime. In particular, the model provides a mechanism to support the use of both low and high viscosity pills, and mud low-shear enhancers - which have been widely used during drilling operations to improve hole cleaning.

The model has been incorporated into a computer program which can predict the CFR under the specified drilling conditions. A series of simplified hole cleaning charts have also been developed which enable the optimum hole cleaning parameters to be determined at the rig-site.
Operator/Contractor Relationships: A Team Approach
Authors: Smith J. R. , Kidwell C. K. , Unger V. E. , Fercho Ed , Helmer C. M.
Published: December 2007

In May 1988, Shell Western E&P Inc. (SWEPI) and partners Elf Aquitaine Petroleum and Conoco Inc. signed a letter of intent with Canadian Marine Drilling Ltd. (Canmar) for provision of exploratory drilling and marine services on leases in OCS Lease Sale 109 in the Chukchi Sea, Alaska. The 5450 blocks offered in the remote sale area west of Point Barrow ranged from 3 to 240 miles (5 to 380 km) offshore in water depths from 26 to 263 feet (8 to 80 m). The principal interest tracts were at least 75 miles (120 km) offshore and north of 70°N latitude. The remoteness and total lack of any oilfield infrastructure required considerable planning and coordination between Operator and Contractor in order to carry out the three-year drilling program efficiently and safely in an environmentally harsh and, at the same time, sensitive area. SWEPI and Canmar developed a close working relationship from the start of the project through a number of participative approaches to the problems that had to be solved.

These included strong reliance on operational planning meetings, post-season analyses, and an overall emphasis on the teamwork required of both parties to carry out the first-ever drilling program in the Chukchi Sea. This approach led to a very successful operation for both parties and emphasizes the positive benefits achievable when Operator and Contractor work as a team.
Ninian Field Wellhead/Tree Commodity Action Team and Manufacturer Alliance Relationship
Authors: Hansen P. A. , Freeland Andy
Published: December 2007

Ninian Field consists of three platforms in the northern North Sea, offshore UK. One hundred and five wellheads and trees are maintained on these platforms at a cost of over $1,700,000.00 per year for tree refurbishment, the purchase of new valve components, and the purchase of new trees to replace aging equipment. There is also the legislative requirement to recertify trees after 5 years in service. To improve business effectiveness, the Operator and primary equipment Manufacturer have formed an Alliance Relationship. The mission statement of this Alliance is to improve safety of designs, trust, cooperation and profitability for both parties, satisfaction levels including cost reductions, guarantee product support, and to develop measures for evaluating success.
Drillpipe Protectors Successfully Used To Reduce Casing Wear in Deep, Directional Well
Authors: Schneider F. F. , Collins G. J.
Published: December 2007

A deep s-shaped well drilled Offshore, Louisiana utilized drillpipe-protector placement practices not commonly used by operating personnel. These placement procedures reduced casing wear and lowered drilling torque. The information presented will focus on the approach used and the observations made while drilling this well.
Advances in Dynamic Bottomhole Assembly Modeling and Dynamic Response Determination
Authors: Spanos P. D. , Payne M. L.
Published: December 2007

Understanding bottom-hole assembly (BHA) dynamic phenomena remains a critical drilling issue due to the substantial cost of associated failures and potential savings from increased drilling efficiency. Many industrial studies have provided useful insight into drillstring dynamics. The current work extends previous efforts by providing a novel BHA model which accounts for several critical response factors and can be augmented to address a variety of other effects. The finite-element technique is used with a frequency-dependent mass matrix to account for the fluid added-mass effect. The BHA excitation is modeled as a vector with components which are monochromatic functions of time. Results from pertinent numerical studies are presented.
General Guidelines for Predicting Fatigue Life of MWD Tools
Authors: Cheatham C. A. , Comeaux B. C. , Martin C. J.
Published: December 2007

A method is presented which gives general guidelines for predicting fatigue life of Measurement-While-Drilling (MWD) tools. The method has been particularly useful as a well planning aid for determining how much (if any) drillstring rotation should be permitted in the angle build sections of medium-radius horizontal wells. The results show that, under most conditions, drillstring rotation should be avoided in doglegs greater than 15 deg/100 ft [15 deg/30 m]. In some cases, even smaller upper dogleg limits should be observed.
Microbiological Waste Decomposition in Drilling Pit at the Oil-Gas-Condensate Fields
Authors: Zinberg M. B. , Surgina T. A. , Ivanowskaya I. B. , Galjan D. A.
Published: December 2007

The article considers microbiological processes in drilling mud pits in the result of keeping in storage solid and liquid drilling mud wastes in them. It was proved that in the result of microorgans activity in the pit toxic biogases are formed-hydrogen sulfide, methane, carbon dioxide.

In some cases these processes advanced sulfate access from the well and continued up to gas saturated productive formations opening.

The usage of bactericides, such as cuprates, potassium bichromate, paraform and etc, inhibits microorgans activity and first of all SRB, which produce hydrogen sulfide in anaerobic conditions. In the result or microorgans inactivation environmental contamination is prevented.
Recent Technological Advances Help Solve Cement Placement Problems in the Gulf of Mexico
Authors: Brady S. D. , Drecq P. P. , Baker K. C. , Guillot D. J.
Published: December 2007

When designing a primary cement job, more emphasis is usually placed on optimizing the cement slurry properties than on its placement in the wellbore. This lack of balance can be easily explained. On one hand, a wide range of additives is now available to control the major cement properties required in a given situation. On the other hand, placement techniques very often still rely on rules of thumb which are not always supported by experience. Recent technological advances should restore the emphasis to cement placement and mud removal. Field engineers can now take into account, quantitatively, most of the key parameters in cement placement and optimize the process.

This paper describes the application of this new technology to a comprehensive cementing design for production casing. This design was developed for a platform in the Green Canyon area of the Gulf of Mexico. In the first part of the paper, the cementing problems encountered before the plan's implementation are discussed. These included (1) poor zonal isolation which necessitated remedial cement squeezes, and (2) gas migration which resulted in casing pressure between the surface and production casings.

In the second part, the authors present the step-by-step methodology which was used to optimize the mud removal process. A computer simulation was used to determine the centralizer placement, fluid properties, and pumping conditions required to provide stable interfaces between the different fluids during the cementing process. The stable interfaces prevented mud pockets or channels from being left in the cement after it was in place. Since the new laminar flow design procedure has been implemented, no remedial squeezes have been required on 11 successive cement jobs. This is especially noteworthy since the average angle of these wells was approximately 50°. In addition, potential gas migration problems have been prevented.
Completion of the KCC 378-H: A Case History
Authors: Pritchett J. L. , Waak K. A. , Chambers R. W. , Conner J. L.
Published: December 2007

A great deal has been published in recent years regarding horizontal well technology. However, little has been pub-lished concerning high rate acid stimulation treatments in openhole sections in horizontal wells. In fact, several articles suggest that a lateral section must be cemented and cased for the appropriate zonal isolation.1 This paper is a case history of a lateral openhole completion which utilized a high rate acid stimulation, polymer gel blocks for diversion, and dynamic spectral gamma ray log analysis.

The Keystone Cattle Company Well No. 378-H, located in Winkler County, Texas was completed in the Wolfcamp Formation of the Flying "W" Field. The completion interval consisted of 1388 ft (423 m) of lateral, openhole section. A 200,000 gal (757 m3) multiple stage, foamed nitrogen acid stimulation was performed using polymer gel blocks for diversion. Five of the acid stages were tagged with three different radioactive isotopes. A spectral gamma ray log was used to identify the treatment intervals during the stimulation to effectively displace the polymer gel blocks.

This paper includes background on the well and objectives for the completion techniques used. The detail procedure and evaluation of the real-time pressure and logging data are also discussed.
Case Histories of Step Rate Tests in Injection Wells
Authors: Salazar Abel , Kumar Anil
Published: December 2007

Knowledge of the formation parting pressure (FPP) is important for efficient operation and surveillance of waterflood projects and CO2 floods. Knowing this information will assist in optimizing recovery by reducing injection rates in wells to control cycling (i.e. prevent fluids from going through uncontrolled fractures or high permeability zones) or by Increasing injection rates to maximize injection efficiency and increase oil production.

A step rate injectivity test (SRIT) is one of the best methods available to determine formation parting pressure, also known as the fracture pressure. Previous step rate tests at Salt Creek have been unsuccessful due to procedural problems resulting in inconclusive results.

This paper outlines the procedures, pitfalls, and field problems encountered while running successful step rate injectivity tests in the Salt Creek Field Unit. Findings obtained from running these tests include: frac gradient is highly dependent on average reservoir pressure; a correlation exists between average reservoir pressure and frac gradient for a particular field; bottom hole injection pressure measurements are extremely important on high rate injection wells; and theoretical formation parting pressure predictions are important in designing test procedures.

We also present results of conducting a decreasing-rate-sequence SRIT. This is the first presentation of such data. The experience and lessons learned from running these step rate tests can be successfully applied to other carbonate reservoirs.
A Simple Approach to Mud-Invasion Correction for Dual Laterolog Resistivities
Authors: Chen Shi-Xin
Published: December 2007

A simple approach to mud invasion correction for dual laterolog resistivities is proposed in this paper. This approach was derived from an idealized formation model for laterolog resistivity measurements. In this model, the measure current is assumed to flow horizontally into the formation and the invasion radius is assumed to be less than the radial depth of investigation of the shallow-laterolog. Instead of a "pseudo-geometrical factor", the tool calibration coefficient was introduced into the laterolog response equations. As a result, the correction for the mud invasion effect on the laterologs can be made without knowing the diameter of mud invasion into the formation. Once the true resistivity of the un-invaded formation is determined from the dual laterologs, the invasion diameter can be further estimated for medium- to high-porosity formations.
Geostatistical/Geological Permeability Characterization of Carbonate Ramp Deposits in Sand Andres Outcrop, Algerita Escarpment, New Mexico
Authors: Senger R. K. , Lucia F. J. , Kerans Charles , Ferris Malcolm , Fogg G. E.
Published: December 2007

The investigation of carbonate-ramp deposits of the upper San Andres Formation that crop out along the Algerita Escarpment, New Mexico, focused on characterizing the complex heterogeneity associated with depositional and diagenetic processes at the interwell scale. Detailed geologic mapping revealed a series of upward-shallowing parasequences, 10 to 40 ft thick, that form the geologic framework for the reservoir model. Parasequence boundaries are typically marked by tight mudstone/wackestone beds that display variable degrees of lateral continuity, ranging from several hundred feet to more than 2,500 ft and are important as potential flow barriers. Detailed permeability measurements (using both mechanical field permeameter and core plugs) of the grainstone rock-fabric unit in parasequence 1 were made at scales of t inch, and 1, 5, 25, and 100 ft. Within parasequence 1, distinct variability of petrophysical characteristics occurs at scales well below those of interwell spacing (660 to 1,330 ft). Geostatistical analyses of permeability measurements indicate varying permeability correlation at the different measurement scales. In all cases, however, approximately half of the permeability variability (variance) is due to locally random heterogeneity (nugget effect). Conditional simulation of permeability in parasequence 1 indicates apparent randomness owing to the large nugget effect. Numerical waterflood simulations using conditional permeability realizations were compared with numerical simulations using geometric-mean permeability distribution and gave similar results. Simulations using small-scale heterogeneity and associated capillary-pressure phenomena will increase sweep efficiency compared with simulations using a facies-averaged permeability distribution with single capillary-pressure curves.
Integrating Technology into Operations: The Team Approach
Authors: Carroll L. B.
Published: December 2007

Integrating new or better technologies into a company's operations is widely recognized as a key to future growth and competitive position.1,2,3,4,5 The power of teams in achieving an aligned workforce, better user acceptance, and improved problem solving is suggested by numerous organizational theorists.6,7 One company combined the need with the opportunity and established Steering Committees using line personnel to direct technology efforts. Five committees have demonstrated the effectiveness of this team approach.
Collar Load Support (CLS) Tubing Running Procedure
Authors: Boutwell D. F. , Gonzalez M. E. , Murrey M. D.
Published: December 2007

Hostile environments found in deep, high pressure gas wells require that extra precaution be taken to extend the productive life of the well These measures often result in the use of corrosion resistant alloys (CRA's) to prevent premature failure of the production tubing due to severe corrosive action on carbon steels.

This paper discusses a new technology that employs a new running procedure for CRA tubulars. The procedure eliminates ALL die penetration marks (slip, elevator, and power tong) created during conventional make up of a tubular connection and installation of the tubing string in the well. This procedure uses a number of new and innovative devices and relies on supporting the tubing string weight on the face of the coupling. In addition, the string is lowered into the well with the use of lift subs around which the elevators are latched. The connections are made up with specially built power tongs that employ new technology for gripping both the tubular body and coupling O.D.

A brief background of the design criteria for the tubing string is presented along with expected installation environment data. The history of the development of the procedure is discussed and the testing program to prove the feasibility of the procedure is detailed. The resulting data and actual performance of the CLS Running Procedure in a case study clearly demonstrates the potential for cost savings.

The cost savings is realized by reducing the wall thickness of CRA tubulars. It accomplishes this by using design criteria based on well environment conditions only. The need for increased wall thickness to compensate for a decrease in the cross-sectional area (due to die penetrations) is eliminated.
Eliminating the Unknowns of Primary Cementing With On-Site Verification and Post-Job Analysis
Authors: Purvis D. L. , St. Clergy John
Published: December 2007

abstract

Historically, computers have been used to perform the initial design for primary cementing. Little has been done with the "Second Phase": on-site verification.

The "Second Phase" involves using measured data obtained on site to optimize the initial (or "First Phase") computer design. This "Second Phase" can eliminate many of the unknowns that are present with the majority of the primary cement jobs done today.

This paper illustrates how on-site design verification, coupled with post-job analysis, is used toimprove the success rate of primary cementing operations. Computer monitoring and modeling, while circulating, can often detect potential problems prior to cementing. At this point, the design parameters are modified, and the design program is re-run on location.

A change in mud rheology, or a restriction in the annulus, may result in increased downhole pressures creating lost circulation problems. By comparing measured circulation pressures with those predicted with an on-site computer model, these types of potential problems can be detected. The actual cause of the pressure discrepancy is found by the process of elimination. After the problem has been isolated, the job is modeled using corrected mud or hole conditions. If lost circulation, gas migration, or poor mud removal is indicated, corrective measures may then be taken.

A checklist of data needed for pre-job simulation is presented along with a discussion of how thisinformation is used. Benefits of realtime monitoring are discussed, including examples of corrective actions taken.

The intent of this paper is to show the benefits to be gained with pre-job simulation and post-jobanalysis.
Oil Industry Decision Making: A Focused Approach
Authors: Collier T. S.
Published: December 2007

The oil and gas business is undergoing a significant restructuring. In order to maintain control of our own destiny and succeed in an increasingly competitive business environment, the industry must set goals which are consistent with its continued success and focus on those goals in every aspect of its strategic management.

By applying an approach to decision making which focuses on the achievement of the key goals required for success at every decision point and systematic follow-up, a firm can greatly increase its ability to succeed in the business environment of the future.
Successful Refracturing in the North Westbrook Unit
Authors: Fleming M. E.
Published: December 2007

This paper documents the results of an active refracturing program in the North Westbrook Unit during the past two years. It was concluded that an increase in fracture conductivity could be attained by employing recent advances in hydraulic fracturing. The use of forced closure combined with the use of larger sand, more aggressive proppant schedules, and intense quality control has resulted in a significant increase in reserves through refracturing.
An Application of Oil Vaporization Evaluation Methods
Authors: Fleckenstein W. W. , Bouck L. S. , Hudgens P. D. , Querin M. E. , Williams L. L.
Published: December 2007

This paper describes and quantifies the benefits of residual oil vaporization in a gas injection project. Vaporized oil is recovered as natural gas liquid (NGL) when the injected gas is produced. In the reservoir application studied, 20% of the liquid hydrocarbons produced were being recovered as NGL.