bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pressure Measurements During Formation Fracturing Operations
Authors: Godbey J.K. , Hodges H.D. 
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 65–69.

Abstract
In order to better understand the fracturing process, bottom-hole pressures were measured during a number of typical fracturing operations. A recently developed system was used that allows simultaneous surface recording of both the bottom-hole and wellhead pressures on the same chart.
The results from six fracturing treatments are summarized on the basis of the pressure data obtained. Although no complete analysis is attempted, the value of accurate pressure measurements is emphasized. Important characteristics of the bottom-hole pressure record do not appear at the wellhead because of the damping effect of the fluid-filled column. In four of the six treatments described, the formations apparently fractured during the initial surge of pressure with only crude oil in the well. The properties of the fluids used during the treatments are given and the fluid friction losses are obtained directly from the pressure records. This technique is also shown to be adequate for determining when various fluids, used during the process, enter the formation.

Introduction
Hydraulic fracturing for the purpose of increasing well productivity is now accepted in many areas as a regular completion and workover practice. Numerous articles have appeared in the literature discussing the various techniques and theories of hydraulic fracturing. In general, three basic types of formation fractures are recognized today. These are the horizontal fracture, the vertical fracture, and fractures along natural planes of weakness in the formation. Any one or all three of these fracture types may be present in a fracturing operation. However, with only the wellhead pressure record as a guide, it is difficult at best to determine if the formation actually fractured, and is almost impossible to determine the type of fracture induced. These difficulties arise in part because the wellhead pressure record, especially when fracturing through tubing, does not accurately reflect the pressure variations occurring at the formation. Several factors contribute to this effect and preclude the possibility of using the wellhead pressure as a basis for accurately calculating the bottom-hole pressure.
Factors Affecting the Rate of Deposition of Cement in Unfractured Perforations During Squeeze-Cementing Operations
Authors: Binley G.W. , Dumbauld G.K. , Collins R.E. 
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 51–58.

Abstract
A mathematical analysis has shown that the primary factors affecting the deposition of cement in unfractured perforations during squeeze-cementing operations are: the properties of the cement slurry, the geometry of the perforations, and the filtration time. The validity of the analysis has been substantiated by laboratory investigations.
The information presented in this paper makes possible the prediction of the rate of deposition of cement in and about unfractured perforations under given squeeze-cementing conditions, the proper filtration time to control the amount of deposition to any desired value, and the deposition properties needed in cement slurries to restrict to any desired degree the formation of nodes of cement solids inside the casing.

Introduction
The deposition of solids against a permeable medium by the process of filtration is an important property of a cement slurry. General recognition of the role of filtration in the use of cement in wells is evident in view of the fact that several patents on low-water-loss cements have been issued during the past few years.
In the conventional, high-pressure squeeze-cementing technique, a large volume of cement slurry is usually displaced into the area surrounding the perforated interval after the formation has been fractured hydraulically. Near the end of the job, the pumping rate is slowed or stopped intermittently in an effort to obtain a high pressure in the wellbore. The way in which a high pressure is obtained is not understood thoroughly, but it is believed to be caused by the deposition of a rigid mass of compacted cement particles either in the fractures of the formations or inside the casing opposite the perforated interval. In a method of squeeze-cementing introduced several years ago, a small amount of cement slurry is squeezed into the perforations at a low pressure to avoid fracturing the formation. The filling of the unfractured perforations with cement particles by the process of filtration is important to the success of this technique.
Improving Miscible Displacement by Gas-Water Injection
Authors: Caudle B.H. , Dyes A.B. 
Published: February 2020

Published in Petroleum Transactions, AIME, Vol. 213, 1958, pages 281–283.Paper presented at 32nd Annual Fall Meeting of Society of Petroleum Engineers in Dallas, Tex., Oct. 6–9, 1957.

ABSTRACT
Miscible displacement recovers all oil in the area contacted by the injected fluid, whereas water or immiscible gas drives usually leave substantial amounts of oil as residual. However, the poor mobility ratios associated with a gas-driven miscible displacement cause the sweep pattern efficiency to be much lower than that obtained with water flooding. One way in which the sweep efficiency in a miscible displacement process can be increased is by decreasing the mobility behind the flooding front. This can be achieved by injecting water along with the gas which drives the miscible slug. This water reduces the relative permeability to gas in this area and thus lowers the total mobility. The main operating conditions for the simultaneous injection process are that a zone of gas exists between the miscible slug and the leading edge of the water and that a sufficient amount of gas be injected with the water to form the gas volume which is being left in the water zone. Laboratory model studies have shown that the ultimate sweep pattern efficiency can be as high as 90 per cent for a five-spot flooding system. If gas alone is used as the driving medium an ultimate sweep-out efficiency of about 60 per cent would be obtained in the same system.

INTRODUCTION
The miscible displacement processes are a step towards total oil recovery. Conventional gas or water drives usually leave 25 to 50 per cent of the oil as residual in the swept portion of the reservoir. This residual can be eliminated if the oil is driven by a fluid with which it is miscible. At some reservoir conditions natural gas will become miscible with the oil. This is the" high pressure gas process". More often, the oil does not contain enough light hydrocarbons to cause the gas to become miscible with the oil at reasonable pressures. In these cases a small band of fluid which is miscible both with the oil and gas must be kept between them. Less than 2 per cent of the reservoir volume of the slug material is needed to keep the displacement miscible.
Process Variables of In Situ Combustion
Authors: Martin William L. , Alexander John D. , Dew John N. 
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 28–35.

Abstract
This paper describes the results of a laboratory investigation conducted to obtain data for an evaluation of the in situ combustion process as a method of producing crude oil from reservoirs. Air and fuel requirements, rates of advance, combustion temperatures, and coke and fluid distributions are presented. The mechanism of oil recovery by in situ combustion is discussed.
Five crude oils ranging in gravity from 10.9 to 34.2 API were produced from a semiadiabatic, unconsolidated sand pack by in situ combustion. Experimental conditions were varied over a wide range in order to determine the inter-relationships of process variables. The minimum air flux requirement for self-sustained combustion was found to be less than 10 scf/hr-ft. The rate of advance of a self-sustained combustion zone was found to be nearly proportional to the air flux at the combustion front.
The effects of pressure and injected air flux were studied in a series of experiments using a 21.2 API crude. A minimum air requirement was observed at an air flux of 20 scf/hr-ft. The oil saturation consumed as fuel averaged 5.5 per cent of pore volume. The effect of air pressure was found to be small for experiments having high combustion efficiencies.
This study should promote a better understanding of the problems and mechanisms involved in laboratory investigations and field applications of the in situ combustion process. The data presented will be useful in the interpretation of results of field tests. When tempered with volumetric sweep efficiencies, the data can be used in making preliminary economic appraisals of the process as applied to reservoirs containing high porosity unconsolidated media.

Introduction
The purpose of this work was to obtain laboratory data for an evaluation of the in situ combustion process as a method of producing crude oil from reservoirs.
In situ combustion basically consists of (1) injecting air into a reservoir through selected input wells to create an air sweep through the reservoir,(2) igniting the crude at the injection well, and (3) propagating the combustion front through the reservoir by continued air injection.
By this means, oil is swept toward producing wells in the area. The fuel for combustion is supplied by heavy residual material (coke) which has been deposited on the sand grains during distillation and cracking of the crude oil ahead of the combustion front.
A Method for Predicting Pressure Maintenance Performance For Reservoirs Producing Volatile Crude Oil
Authors: Jacoby R.H. , Berry V.J. 
Published: February 2020

Published in Petroleum Transactions, AIME, Vol. 213, 1958, pages 59–64. Paper presented at 32nd Annual Fall Meeting of SPE in Dallas, Texas, Oct. 6–9, 1957.

Abstract
When dry gas is injected into a reservoir containing a volatile crude oil, a significant amount of the reservoir liquid phase may become vaporized. The resultant rich gas phase, when subsequently produced, contributes to tank oil production. This contribution assumes greater importance, the more volatile the oil involved. Oil recovery may be substantially greater than that predicted by conventional frontal-drive methods, which do not consider the vaporization equilibrium between the reservoir oil phase and the injected gas.
A calculation method has been developed to account for vaporization of the reservoir liquid phase during gas-injection operations, and for the tank oil production which results from this factor. Recovery performance calculations are presented for a reservoir containing a highly volatile oil. Tank oil recovery is calculated to be about twice that predicted by the use of the conventional frontal-drive equations. In contrast to usual pressure maintenance performance results, in which the gas-oil ratio rises at an increasing rate after gas breakthrough, the predicted gas-oil ratio rises rapidly to about 12,000 scf/bbl and then rises much less rapidly. During gas injection, most of the reservoir liquid phase contacted is evaporated by the dry injection gas. The gas-oil ratio during this period is dependent upon reservoir pressure. The higher the operating pressure, the lower the gas-oil ratio. The predicted behavior is in accordance with laboratory PVT tests made to simulate the vaporization behavior. In addition to recovery performance predictions, results of the calculation procedure include complete wellstream composition data of value in the design of gasoline plant facilities often used in connection with gas-injection operations.
A Theoretical Description of Water-Drive Processes Involving Viscous Fingering
Authors: van Meurs P. , van der Poel C. 
Published: February 2020

Published in Petroleum Transactions, AIME, Vol. 213, 1958, pages 103–112.Paper presented at 32nd Annual Fall Meeting of SPE in Dallas, Texas, Oct. 6–9, 1957.

Abstract
From observations of the linear displacement of oil by water from a porous medium as visualized in transparent models, new insight into the mechanism of viscous fingering, as occurring in the case of unfavorable oil-water viscosity ratios, has been obtained. A mathematical description of the observed phenomena leads to formulas expressing both oil production and pressure drop across the formation as a function of cumulative water injection with the oil-water viscosity ratio as a parameter. Theoretical results are compared with those obtained from scaled laboratory experiments in sand-filled tubes in which water was injected at the one end and production was obtained from the other end. In the second part of the paper the same principles are used to calculate a more realistic production scheme in which production of oil and water is obtained from wells regularly distributed over the field. Results show satisfactory agreement with production data of an actual oil field. Application of the theory is extremely simple as only a limited number of readily available parameters have to be known and results are presented in an analytical form.

Introduction
When oil is displaced from a porous medium by water having a viscosity lower than the oil, the oil-water interface is essentially unstable and has the tendency to break up into what are called "fingers" or "streamers". This viscous fingering has been noted before by Engelberts and Klinkenberg and has recently been demonstrated in transparent models by van Meurs. It is highly questionable whether it is at all possible to perform relative permeability measurements in the laboratory reproducing the same distribution of water and oil in the cores as present in practice. Therefore, we based our descriptive theory on an idealized model which was "tailored" to the fingering mechanism as observed in transparent models under scaled conditions. This approach was the more attractive, as a highly simplified model had already yielded an adequate description of the process. Though we are aware our theoretical approach can be extended in several ways, it is given here in its simplest form to explain the fundamental principles and to avoid complicated formulas.
Modern contraceptive use among female refugee adolescents in Northern Uganda: prevalence and associated factors
Authors: Bakesiima Ritah , Cleeve Amanda , Larsson Elin , Tumwine James K. , Ndeezi Grace , Danielsson Kristina Gemzell , Nabirye Rose Chalo , Kashesya Jolly Beyeza 
Published: February 2020

Abstract
Background Adolescent pregnancies are persistently high among refugees. The pregnancies have been attributed to low contraceptive use in this population. The aim of this study was to determine the prevalence of and factors associated with modern contraceptive use among female refugee adolescents in Northern Uganda. Methods This was a cross sectional study employing both descriptive and analytical techniques. The study was carried out in Palabek refugee settlement in Northern Uganda from May to July 2019. A total of 839 consenting refugee adolescents who were sexually active or in-union were consecutively enrolled. Interviewer administered questionnaires were used for data collection. Results Modern contraceptive prevalence was 8.7% (95% CI: 7.0 to 10.8). The injectable was the most commonly used modern contraceptive method (42.5%), and most of the participants had used the contraceptives for six months or less (59.7%). Reasons for not using modern contraceptives included fear of side effects (39.3%), partner prohibition (16.4%), and the desire to become pregnant (7.0%). Participants who were married (OR=0.11, 95% CI: 0.04 to 0.35, p<0.001), cohabiting (OR=0.43, 95% CI: 0.20 to 0.93, p=0.032) or having an older partner (OR=0.93, 95% CI: 0.86 to 0.99, p=0.046) were less likely to use modern contraceptives. Conclusion Modern contraceptive use among female refugee adolescents was very low, and few reported a desire to become pregnant, leaving them vulnerable to unplanned pregnancies. Least likely to use modern contraceptives were participants who were married/cohabiting and those having older partners implying a gender power imbalance in fertility decision making. There is an urgent need for innovations to address the gender and power imbalances within relationships, which would shape decision-making and increase modern contraceptive use among refugee adolescents.
PRZESTĘPSTWO CIĄGŁE WE WSPÓŁCZESNYM ROSYJSKIM PRAWIE KARNYM
Authors: Machlańska Joanna 
Published: February 2020

StreszczenieZnamiennym dla współczesnego rosyjskiego prawa karnego jest fakt, że do tej pory postanowienie Plenum Sądu Najwyższego ZSRR z 4 marca 1929 r., które definiuje przestępstwo ciągłe, stanowi wstęp do rozważań o tej instytucji, co z polskiego punktu widzenia stanowi fenomen, gdyż żadnemu z judykatów wydanych w okresie PRL nie przypisywano tak ogromnego znaczenia. Należy także podkreślić, że również w obecnie obowiązującym rosyjskim Kodeksie karnym z 1996 r. nie uregulowano konstrukcji przestępstwa ciągłego, co tłumaczone jest tym, że po dzień dzisiejszy nie wypracowano wspólnego stanowiska odnośnie do jego przesłanek czy kształtu, co jednakże budzi zastrzeżenia z punktu widzenia zasady nullum crimen sine lege.
Peak Outpatient and Emergency Department Visit Forecasting for Patients With Chronic Respiratory Diseases Using Machine Learning Methods: Retrospective Cohort Study
Authors: Peng Junfeng , Chen Chuan , Zhou Mi , Xie Xiaohua , Zhou Yuqi , Luo Ching-Hsing 
Published: February 2020

Background
The overcrowding of hospital outpatient and emergency departments (OEDs) due to chronic respiratory diseases in certain weather or under certain environmental pollution conditions results in the degradation in quality of medical care, and even limits its availability.

Objective
To help OED managers to schedule medical resource allocation during times of excessive health care demands after short-term fluctuations in air pollution and weather, we employed machine learning (ML) methods to predict the peak OED arrivals of patients with chronic respiratory diseases.

Methods
In this paper, we first identified 13,218 visits from patients with chronic respiratory diseases to OEDs in hospitals from January 1, 2016, to December 31, 2017. Then, we divided the data into three datasets: weather-based visits, air quality-based visits, and weather air quality-based visits. Finally, we developed ML methods to predict the peak event (peak demand days) of patients with chronic respiratory diseases (eg, asthma, respiratory infection, and chronic obstructive pulmonary disease) visiting OEDs on the three weather data and environmental pollution datasets in Guangzhou, China.

Results
The adaptive boosting-based neural networks, tree bag, and random forest achieved the biggest receiver operating characteristic area under the curve, 0.698, 0.714, and 0.809, on the air quality dataset, the weather dataset, and weather air quality dataset, respectively. Overall, random forests reached the best classification prediction performance.

Conclusions
The proposed ML methods may act as a useful tool to adapt medical services in advance by predicting the peak of OED arrivals. Further, the developed ML methods are generic enough to cope with similar medical scenarios, provided that the data is available.
Methicillin-Resistant Staphylococcus aureus Eradication and Decolonization in Children Study (Part 1): Development of a Decolonization Toolkit With Patient and Parent Advisors
Authors: Moore Courtney M , Wiehe Sarah E , Lynch Dustin O , Claxton Gina EM , Landman Matthew P , Carroll Aaron E , Musey Paul I 
Published: February 2020

Background
Community-acquired methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections affect many healthy children. A significant number of these children are hospitalized and require surgical incision and drainage (I&D). Once sent home, these children and families are asked to complete burdensome home decolonization and hygiene procedures in an effort to prevent the high rate of recurrent infections.

Objective
This component of the Methicillin-resistant Staphylococcus aureus Eradication and Decolonization in Children (MEDiC) study aimed to develop a toolkit to assist MEDiC study participants in completing MRSA decolonization and hygiene procedures at home (the MEDiC kit).

Methods
In all, 5 adolescents (aged 10-18 years) who had undergone an I&D procedure for a skin infection and 11 parents of children who had undergone an I&D procedure for a skin infection were engaged in a 4-hour group workshop using a human-centered design approach. The topics covered in this workshop and analyzed for this paper were (1) attitudes about MRSA decolonization procedures and (2) barriers to the implementation of MRSA decolonization and hygiene procedures. The team analyzed the audio and artifacts created during the workshop and synthesized their findings to inform the creation of the MEDiC kit.

Results
The workshop activities uncovered barriers to successful completion of the decolonization and hygiene procedures: lack of step-by-step instruction, lack of proper tools in the home, concerns about adverse events, lack of control over some aspects of the hygiene procedures, and general difficulty coordinating all the procedures. Many of these could be addressed as part of the MEDiC kit. In addition, the workshop revealed that effective communication about decolonization would have to address concerns about the effects of bleach, provide detailed information, give reasons for the specific decolonization and hygiene protocol steps, and include step-by-step instructions (preferably through video).

Conclusions
Through direct engagement with patients and families, we were able to better understand how to support families in implementing MRSA decolonization and hygiene protocols. In addition, we were able to better understand how to communicate about MRSA decolonization and hygiene protocols. With this knowledge, we created a robust toolkit that uses patient-driven language and visuals to help support patients and families through the implementation of these protocols.

Trial Registration
ClinicalTrials.gov NCT02127658; https://clinicaltrials.gov/ct2/show/NCT02127658