bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

ABSTRACT
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

ABSTRACT
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

Abstract
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

Abstract
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

ABSTRACT
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

ABSTRACT
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

ABSTRACT
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

ABSTRACT
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

ABSTRACT
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

Abstract
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

Abstract
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

Abstract
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.