bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling of Fracture Ballooning in Naturally Fractured Reservoirs: A Sensitivity Analysis
Authors: Mehrabi Mehran , Zeyghami Mohammad , Shahri Mojtaba Pordel 
Published: August 2012

Abstract
Fracture ballooning usually occurs in naturally fractured reservoirs and is often mistakenly regarded as an influx offormation fluid, which may result in misdiagnosed costly operations. Several models have been developed to treat this phenomenon and distinguish it from conventional losses or kicks. Among these borehole ballooning models and mechanisms, opening/closing of natural fractures is considered to have the main role in naturally fractured reservoirs.
In this study a mathematical model is developed for mud invasion through a disk-shaped and deformable fracture with two impermeable walls and a limited extension. A governing equation is derived based on the lubrication approximation theory (Reynolds's Equation) for radial flow in a single fracture. Considering an exponential deformation law to describe the pressure-aperture relationship, and a yield-power-law model to describe mud rheology, makes this model more general and much closer to the reality than the previous ones. Describing the fluid rheology with yield-power-law model turns the governing equation into a versatile model as it includes various types of drilling mud rheology.
The governing equation is solved numerically using finite difference method. Results show how different parameters can affect fracture ballooning and volume and rate of mud loss/gain. The effects of several parameters related to the mechanical properties of the fracture are analyzed. Shortcomings of the proposed model are outlined.
Estimating the Effect of Specific Gravity of Weighting Material on the Solids Concentration of Weighted Mud
Authors: Bahadori Alireza 
Published: August 2012

Abstract
An important function of drilling mud is the control of formation fluid pressure to prevent blowouts. The density of the mud must be raised at times to stabilize incompetent formations. Any substance that is denser than water and that does not adversely affect other properties of the mud can be added to raise the density to some extent. Obviously, the specific gravity of the weighting agent is of primary importance, especially in very heavy muds. The fractional volume occupied by the added solid is a major limiting factor in its use. In this work a simple-to-use correlation has been developed to predict the effect of the specific gravity of the weighting material and the density of mud on the solids concentration of weighted muds. Estimations are found to be in excellent agreement with the reliable data in the literature with average absolute deviation being less than 0.3%.
Hydrodynamics of Sand-oil-Gas Multiphase Flow in a Near Vertical Well
Authors: Adeyanju O. A. , Oyekunle L. O. 
Published: August 2012

ABSTRACT
A calculation method for predicting Bottom Hole Pressure (BHP) based on easily obtainable wellhead parameter has been the preferred method in the petroleum industry. But, the predictive capability of the existing correlations is a thing of concern to the oil industry operators. This is due to the inability of the existing models and correlations to account for the presence of the sand particles in the flow stream; also the requirement for the well to be shut-in for BHP predictions is counter productive. These inadequacies were corrected in the proposed model. Results showed that the average pressure drop in the multiphase fluid flow using the proposed model is higher than the pressure drops determined using existing models and correlations. The effects of the fluid density, viscosity and velocity on the sand particles lifting were also investigated and results showed that the sand particle lifting was improved by higher fluid velocity and density and lower fluid viscosity. Validation of the proposed model with field data showed that the model predicts the field BHP data better than any of the existing models and correlations, based on the Average Absolute Deviation (AAD) value of 6.53 returned by the proposed model compared to AAD value of between 13.56 and 24.67 returned by the existing models and correlations.
Managing Paraffin Wax Deposition in Oil Wells – Related Problems in Nigerian Oil Fields
Authors: Oseghale C. Ijogbemeye , Akpabio E. J 
Published: August 2012

Abstract
The estimation and prediction of wax formation and the understanding of the physicochemical characteristics of the wax phase are of major importance in flow assurance. The characterization of the oil and wax can provide useful estimates of the parameters and behavior required for operational engineering process developments and/or physical modifications to the processing of crude oils, aiming at the reduction of costs of production and transportation. The strategy employed in this study was to use temperature and fluid characterization analysis of Nigerian crude to predict the potential for paraffin wax related problems in Nigerian oilfields. This approach defined the oilfields with probably high risk of wax deposition potential amongst Nigerian crude. The synopsis of this paper proved that some Nigerian oilfield presents a potentially serious problem.
Temperature Prediction Model for Flowing Distribution in Wellbores and Pipelines
Authors: Charles Y. O , Igbokoyi A. O 
Published: August 2012

Abstract
Down-hole temperature data are important information needed to understand flowing conditions. Since wellbore temperature profile is affected by inflow profiles, it is then possible to predict inflow of fluid into the wellbore.
While gas production usually causes a temperature decrease due to Joule Thomson effect water entry result in warming of the wellbore. Warmer water entry is as a result of inflow from a warmer aquifer zone due to water coning. Water entry by water coning can therefore easily be detected from temperature profile since it increases the wellbore temperature.
In this study, we successfully developed a temperature prediction model which calculates temperature profiles for fluid flowing in the wellbore and considers Joule Thomson coefficient as a function of mass flow rate of the fluid phases (oil, water, and gas). We modified the Alves et al temperature equation into three phase temperature equation and it was used to predict water and gas inflow into the wellbore. Correlations that can be applied to oil field ranges of temperature and pressure were used to determine fluid properties. The model was used to investigate the effect of gas and water entry that created change in temperature profile along the wellbore. The temperature equation can be applied to pipelines or production and injection wells under single phase, two phase, and three phase flow for horizontal, vertical, and inclined wells
Cases were considered to analyze the effect of water and gas entry into the wellbore. Fluid inflow was predicted from the temperature profile, the result shows that water entry increases wellbore temperature and gas entry decreases wellbore temperature.
Revision of Unicondylar to Total Knee Arthroplasty: A Systematic Review
Authors: Siddiqui Nashat A , Ahmad Zafar M 
Published: August 2012

Isolated unicompartmental osteoarthritis in the young patient is a difficult problem to treat; they may be too young to consider total knee arthroplasty due to difficulties with inevitable future revision. Unicompartmental knee arthroplasty is one possible solution as it is perceived by some as being a smaller surgical insult than total knee arthroplasty, with easier revision to total knee arthroplasty than a revision total knee arthroplasty. A total knee arthroplasty performed as a revision unicondylar knee arthroplasty is thought by some authors to have equivalent functional outcomes to a primary total knee replacement.However, there have been several studies suggesting that revision is not as simple as suggested, and that function is not as good as primary total knee arthroplasty.We performed a systematic review of the literature regarding outcomes after revision of a unicondylar knee arthroplasty.Although there are many studies proposing selective use of the unicondylar knee arthroplasty, there are a number of studies highlighting difficulties with revision and poorer outcomes, and, therefore, the unicondylar knee arthroplasty cannot be considered a small procedure that will 'buy time' for the patient, and have results equal to a primary knee arthroplasty when revised. Further controlled studies, ideally randomised, are required before final conclusions can be drawn.
Anterior Cruciate Ligament Rupture and Osteoarthritis Progression
Authors: Wong James Min-Leong , Khan Tanvir , Jayadev Chethan S , Khan Wasim , Johnstone David 
Published: August 2012

Anterior Cruciate Ligament (ACL) rupture is a common sporting injury that frequently affects young, athletic patients. Apart from the functional problems of instability, patients with ACL deficient knees also develop osteoarthritis. Although this is frequently cited as an indication for ACL reconstruction, the relationship between ACL rupture, reconstruction and the instigation and progression of articular cartilage degenerative change is controversial.The purpose of this paper is to review the published literature with regards ACL rupture and the multifactorial causes for osteoarthritis progression, and whether or not this is slowed or stopped by ACL reconstruction.There is no evidence in the published literature to support the view that ACL reconstruction prevents osteoarthritis, although it may prevent further meniscal damage. It must be recognised that this conclusion is based on the current literature which has substantial methodological limitations.
Dental arch parameters of the displacement and nondisplacement sides in subjects with unilateral palatal canine ectopia
Authors: Al-Khateeb Susan , Abu Alhaija Elham S. , Rwaite Ashwaq , Burqan Bader Alddin 
Published: August 2012

ABSTRACT

Objective:
To compare arch perimeter and teeth size, number, and shape between the two sides of the dental arch—the canine displacement side (DS) and the nondisplacement side (NDS)—in subjects with unilateral palatally displaced canine (PDC).

Materials and Methods:
Orthopantomograms (OPTs) of 240 subjects with unilateral PDC and 240 OPT matching controls were used. Additionally, study casts of 100 study subjects and 100 controls were used. The age of subjects ranged between 14 and 25 years. Dental casts were digitized and several parameters were recorded.

Results:
The transverse width from midpalatal line to the buccal segment and the palatal area on the DS was larger than that in the NDS (P &lt; .05 to .001), with no difference in tooth size between both sides. Maxillary second premolars, canines, and lateral incisors in the PDC group were smaller than those in control group. Peg-shaped lateral incisors were significantly more frequent in the study group (P &lt; .001).

Conclusions:
The transverse width of the DS was larger than that of the NDS. Both sides were generally smaller than those of the control group. Tooth size in the DS was comparable to that in the NDS but smaller than those of the control group. A missing or peg-shaped lateral incisor was the most common reported anomaly.
Comparison of Initial Nonoperative and Operative Management of Radial Nerve Palsy Associated With Acute Humeral Shaft Fractures
Authors: Liu Geng-yan , Zhang Chao-yue , Wu Hong-wei 
Published: August 2012

Educational Objectives

As a result of reading this article, physicians should be able to:

1.
Become familiar with the available treatment approaches for radial nerve palsy associated with humeral shaft fractures.

2.
Understand the strengths and limitations of the current treatment approaches for radial nerve palsy associated with humeral shaft fractures.

3.
Become familiar with the available evidence regarding the effectiveness of operative and nonoperative treatment for radial nerve palsy associated with humeral shaft fractures.

4.
Understand when operative or nonoperative management of radial nerve palsy associated with humeral shaft fractures may be appropriate.
Revision Total Hip Arthroplasty in Jehovah’s Witnesses
Authors: Harwin Steven F. , Pivec Robert , Johnson Aaron J. , Naziri Qais , Mont Michael A. 
Published: August 2012

Revision total hip arthroplasty (THA) is associated with greater blood loss than primary THA. Jehovah’s Witnesses will not accept transfusions of blood or blood products and are thus at an increased risk for complications due to perioperative anemia. The purpose of this study was to report the clinical outcomes, radiographic outcomes, morbidity, and mortality of Jehovah’s Witnesses who were medically optimized and underwent revision THA.
Databases from 2 institutions were reviewed to identify 10 patients (11 THAs) who were Jehovah’s Witnesses undergoing revision THA with a minimum 24-month follow-up. At most recent follow-up, all patients were doing well clinically, with Harris Hip Scores greater than 80 points. Radiographic evaluation demonstrated well-positioned components and no progressive radioluciencies. No major perioperative medical or surgical complications occurred in patients undergoing THA. Revision THA for aseptic causes results in good clinical outcomes in patients who are preoperatively optimized before undergoing surgery.
Immediate Weight Bearing of Comminuted Supracondylar Femur Fractures Using Locked Plate Fixation
Authors: Granata Jaymes D. , Litsky Alan S. , Lustenberger David P. , Probe Robert A. , Ellis Thomas J. 
Published: August 2012

Comminuted supracondylar femur fractures (AO-OTA 33A3) are commonly treated with locked plates. Weight bearing is generally restricted for 6 to 12 weeks until radiologic evidence exists of sufficient callous to support weight bearing. Recent clinical studies have reported high nonunion rates with distal femur locked plates. In an attempt to induce beneficial motion across the fracture site, some studies have recommended earlier weight bearing. The purpose of the current study was to determine the biomechanical feasibility of an immediate weight-bearing rehabilitation protocol to encourage healing of distal femur fractures treated with lateral locked plate fixation.
Sixteen fresh-frozen cadaveric femora were used for this study. A 2.5-cm supracondylar gap osteotomy was made. Ten-hole, 4.5-mm distal femur locking plates were used with a standardized screw configuration that maximized the working length. The specimens were placed in a servohydraulic testing machine and axially loaded (unidirectional) at 1 Hz for up to 200,000 cycles. Failure was defined as 1 cm of deformation of the construct. The staircase method was used to determine the fatigue limit of the construct. The fatigue limit was calculated to be 1329±106 N. No specimen failed through the non-locking diaphyseal screws. Plastic deformation, when present, occurred at the metaphyseal flare of the plate. The fatigue limit of the locked plate constructs equaled 1.9 times body weight for an average 70-kg patient over a simulated 10-week postoperative course. Given that distal femoral loads during gait have been estimated to be more than 2 times body weight, the data from this study do not support immediate full weight bearing.
Backout of the Helical Blade of Proximal Femoral Nail Antirotation and Accompanying Fracture Nonunion
Authors: Niikura Takahiro , Lee Sang Yang , Matsumoto Tomoyuki , Fukui Tomoaki , Kawakami Yohei , Akisue Toshihiro , Kuroda Ryosuke , Kurosaka Masahiro 
Published: August 2012

This article describes a case of backout of the helical blade, a rare complication of proximal femoral nail antirotation. A 31-year-old man had sustained a trochanteric fracture of his right femur. Fracture fixation using proximal femoral nail antirotation and autologous bone grafting 7 months later were performed at another hospital. However, bony union was not obtained, and the patient’s pain and limp persisted. Therefore, he presented to the current authors. A radiograph taken at presentation revealed backout of the helical blade and fracture nonunion. A radiograph taken 1 month later showed a more advanced backout of the helical blade. The authors performed exchange nailing supplemented with transplantation of peripheral blood CD34-positive cells and autologous bone grafting. The proximal femoral nail antirotation was revised to a long gamma 3 nail, and a U-lag screw was used to obtain better stability. The postoperative course was uneventful. The patient regained ambulation without pain or support at 12 weeks postoperatively. Radiographic bony union was completed 9 months postoperatively. At 1-year follow-up, he could run and stand on the previously injured leg and had returned to work.
Backout of the helical blade should be considered as a possible complication of proximal femoral nail antirotation. Incomplete fixation of the helical blade is the possible reason for backout. The use of a helical blade in young patients may cause difficulty in insertion and result in incomplete fixation.
Arthroscopically Assisted Percutaneous Fixation and Bone Grafting of a Glenoid Fossa Fracture Nonunion
Authors: Sears Benjamin W. , Lazarus Mark D. 
Published: August 2012

Arthroscopy is commonly used for evaluating intra-articular fracture patterns and assessing postfixation reduction; however, the use of arthroscopy for the definitive treatment of articular fracture nonunion has not been reported. This article describes a case of symptomatic glenoid fossa fracture nonunion that was successfully treated with arthroscopically assisted percutaneous screw fixation and bone grafting.
A 48-year-old laborer sustained a glenoid fossa fracture following a fall from a height. An initial period of nonoperative management was attempted; however, the patient reported continued shoulder pain during his rehabilitation course. Imaging 5 months after injury showed no osseous union at the fracture. Using an arthroscopically assisted technique, percutaneous fixation and bone grafting of the nonunion with cancellous allograft was performed. Postoperatively, the patient progressed through a structured therapy program, and his pain improved. A computed tomography scan 4 months postoperatively showed osseous union at the fracture site.
To the authors’ knowledge, this is the first report in the literature of definitive arthroscopically assisted bone grafting and percutaneous fixation of a diarthrodial joint nonunion. Advantages of arthroscopic fixation of glenoid fossa fracture nonunion include avoiding potential axillary nerve injury and preserving the native subscapularis insertion, which may be important if subsequent procedures require access to the anterior access to the joint.
Isolated Ring Finger Flexor Digitorum Profundus Entrapment After Closed Reduction and Intramedullary Fixation of Both-bone Forearm Fracture
Authors: Song Daniel J. , Kennebrew Garry J. , Jex Jefferson W. 
Published: August 2012

Flexor tendon entrapment after a pediatric forearm fracture is a rarely reported complication that is often diagnosed late. Flexor tendon entrapment is more frequently reported after distal forearm fractures, and possible etiologies include fibrosis secondary to hemorrhage at the fracture site and simple entrapment of the muscle belly.
This article describes a case of ring finger flexor digitorum profundus entrapment in a 12-year-old boy with a closed both-bone forearm fracture that was treated with closed reduction and intramedullary nail fixation. Preoperatively, the patient had full flexion and extension of all fingers. The entrapment was noted at the first postoperative follow-up when the patient could fully extend the ring finger proximal interphalangeal joint but was unable to concomitantly extend the metacarpal phalangeal joint. Magnetic resonance imaging and ultrasound were obtained to identify the entrapment site. Intraoperatively, a portion of the flexor digitorum profundus musculotendinous junction was entrapped in the fracture site. After release of the entrapment, the patient gained immediate passive range of motion. Subsequently, the hardware was removed, and the patient healed and regained full ring finger function.
To the authors’ knowledge, this is the only report of isolated ring finger flexor digitorum profundus entrapment after closed reduction and intramedullary fixation of a pediatric forearm fracture. The authors recommend vigilant physical examination of passive and active range of motion of all digital joints with the wrist in flexion and extension before and after bony manipulation.
Atraumatic Acute Carpal Tunnel Syndrome in a Patient Taking Dabigatran
Authors: Sibley Paul A. , Mandel Richard J. 
Published: August 2012

Acute carpal tunnel syndrome is an uncommon diagnosis most often related to blunt trauma requiring immediate surgical decompression to avoid serious sequelae. Patients who present with bleeding-related acute carpal tunnel syndrome tend to have severe pain, rapid onset of swelling, and neurologic symptoms that appear early and progress rapidly secondary to mass effect. Acute carpal tunnel syndrome can occur in anticoagulated patients spontaneously or after minor trauma.
This article describes a case of a 57-year-old man with progressive pain and paresthesias in the median nerve distribution after reaching for a picture frame. He was taking dabigatran, a direct thrombin inhibitor, for atrial fibrillation. He developed acute carpal tunnel syndrome secondary to spontaneous bleeding into the carpal canal and flexor tenosynovium with hematoma formation requiring surgical decompression. He reported immediate pain relief postoperatively, had no further bleeding complications, and regained full median nerve function within 2 months.
Dabigatran has gained recent popularity for the treatment of atrial fibrillation. Unlike warfarin, its use does not involve regular laboratory monitoring or dose titration. The risks and benefits of dabigatran should be considered carefully by the prescriber, particularly in patients taking medications that may alter its metabolism. Aspirin and nonsteroidal anti-inflammatory drugs may have effects similar to dabigatran and may increase the risk of bleeding problems. Should acute carpal tunnel syndrome occur, the authors recommend prompt surgical decompression rather than conservative management. The modification of anticoagulant therapy should be considered on a case-by-case basis.
Ankle Fracture Following Hip Arthroscopy
Authors: Schiffman Eric D. , McCarthy Joseph C. , Kwon John Y. 
Published: August 2012

This article describes a case of an ankle fracture following hip arthroscopy. A 58-year-old woman underwent hip arthroscopy for a labral tear. She was placed in a lateral decubitus position with her foot in a padded boot. Traction was maintained for approximately 30 minutes. She was instructed to bear weight as tolerated with crutches postoperatively. At 2-week follow-up, she reported ipsilateral ankle pain. Radiographs revealed a minimally displaced medial malleolus fracture. She was treated with a cast followed by a cam walker boot and successfully went on to complete union and resolution of her symptoms.
The following risk factors exist for ankle fracture after hip arthroscopy: history of ankle sprains, ligamentous laxity (more common in women), and small feet with large calves (more likely to become plantarflexed during traction). Distraction performed with the ankle rotated is also likely to place added stress on the medial or lateral ligamentous structures.
It is important to counsel patients preoperatively about the risk of ankle pain after hip arthroscopy, to be aware of the possibility of ankle pathology postoperatively, and to have a low threshold for ordering radiographs. Radiographs are warranted if patients continue to have ankle pain after 72 hours postoperatively.