Thermophilic biodigestion of fermented sugarcane molasses in high-rate structured-bed reactors: Alkalinization strategies define the operating limits

2021 ◽  
Vol 239 ◽  
pp. 114203
Author(s):  
Lucas Tadeu Fuess ◽  
Marcelo Zaiat ◽  
Claudio Augusto Oller do Nascimento
Keyword(s):  
High Rate ◽  
Sugarcane Molasses ◽  
Operating Limits

Well-Flux Surveillance and Ramp-Up Method for Openhole Standalone Screen Completion

2021 ◽  
Vol 73 (03) ◽  
pp. 53-54
Author(s):  
Judy Feder
Keyword(s):  
Technical Conference ◽  
High Rate ◽  
Well Performance ◽  
University Of Houston ◽  
Surveillance Model ◽  
Sand Control ◽  
Operating Limits ◽  
Direct Linkage ◽  
Flux Model ◽  
Gravel Pack

This article, written by JPT Technology Editor Judy Feder, contains highlights of paper SPE 201662, “A Well-Flux Surveillance and Ramp-Up Method for Openhole Standalone Screen Completion,” by Mehmet Karaaslan and George K. Wong, University of Houston, and Kevin L. Soter, SPE, Shell, et al., prepared for the 2020 SPE Annual Technical Conference and Exhibition, originally scheduled to be held in Denver, Colorado, 5-7 October. The paper has not been peer reviewed. Production and surveillance engineers need practical models to help maximize production while avoiding ramping up the well to an extent that the completion is damaged, causing well impairment or failure. The complete paper presents a well-flux surveillance method to monitor and ramp up production for openhole standalone screen (OH-SAS) completions that optimizes production by considering risks of production impairment and screen-erosion failure. Challenges of Increased Production vs. Well Failure The problem of increased production vs. the risk of well impairment or failure is a pressing problem for sand-control wells in deepwater, where projects tend to have a small number of high-rate wells. In such environments, any well impairments or failures greatly affect the project economics. Following unloading, well surveillance faces the critical step of ramping up to-ward the well’s designed peak rate for the first time when the actual well performance is uncertain. To reduce risk of well impairment or failure, surveillance information and models are needed to help make adjustments during the ramp-up process. Different models are available, from simple to complex and from small to large amounts of input data and computational efforts. Simple nonsurveillance models use field-derived operating limits of completion pressure drop and flow velocity or flux. They are non-surveillance models in the sense that no direct linkage of surveillance results to update flux calculations exists. Simple surveillance models use pressure transient analysis (PTA) results and completion information to evaluate changing well performance and adjust the ramp-up and long-term surveillance operations. The complex surveillance model evaluates well performance and adjusts well operations using probabilistic completion failure risks and coupled reservoir and completion simulations. These models mainly focus on cased-hole gravel pack and frac-pack applications. For openhole completions with sand control, the literature offers limited ramp-up surveillance references. The objective of the well-flux model described in the complete paper is to ramp up the well safely and optimize production using PTA results as surveillance inputs to calculate completion fluxes for well impairment or failure assessment. The method follows an approach presented in the literature.

A Replica Technique for the Inside Surfaces of Small Diameter Pipes and Tubes

1967 ◽  
Vol 25 ◽  
pp. 352-353
Author(s):  
T. G. Gregory
Keyword(s):  
Polyvinyl Chloride ◽  
Small Diameter ◽  
Replica Technique ◽  
Tube Size ◽  
Inside Diameter ◽  
Complete Inspection ◽  
Operating Limits

A nondestructive replica technique permitting complete inspection of bore surfaces having an inside diameter from 0.050 inch to 0.500 inch is described. Replicas are thermally formed on the outside surface of plastic tubing inflated in the bore of the sample being studied. This technique provides a new medium for inspection of bores that are too small or otherwise beyond the operating limits of conventional inspection methods.Bore replicas may be prepared by sliding a length of plastic tubing completely through the bore to be studied as shown in Figure 1. Polyvinyl chloride tubing suitable for this replica process is commercially available in sizes from 0.037- to 0.500-inch diameter. A tube size slightly smaller than the bore to be replicated should be used to facilitate insertion of the plastic replica blank into the bore.

Structure of Palladium Single-Crystal Films Prepared by Flash Evaporation onto (001) NaCl Substrates

1970 ◽  
Vol 28 ◽  
pp. 456-457
Author(s):  
L. E. Murr ◽  
G. Wong
Keyword(s):  
Single Crystal ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
High Rate ◽  
Flash Evaporation ◽  
Optimum Load ◽  
Single Crystal Films ◽  
Crystal Films ◽  
A Current

Palladium single-crystal films have been prepared by Matthews in ultra-high vacuum by evaporation onto (001) NaCl substrates cleaved in-situ, and maintained at ∼ 350° C. Murr has also produced large-grained and single-crystal Pd films by high-rate evaporation onto (001) NaCl air-cleaved substrates at 350°C. In the present work, very large (∼ 3cm2), continuous single-crystal films of Pd have been prepared by flash evaporation onto air-cleaved (001) NaCl substrates at temperatures at or below 250°C. Evaporation rates estimated to be ≧ 2000 Å/sec, were obtained by effectively short-circuiting 1 mil tungsten evaporation boats in a self-regulating system which maintained an optimum load current of approximately 90 amperes; corresponding to a current density through the boat of ∼ 4 × 104 amperes/cm2.

Rapid Freezing of Freeze-Etch Specimens

1980 ◽  
Vol 38 ◽  
pp. 752-755
Author(s):  
A. Elgsaeter ◽  
T. Espevik ◽  
G. Kopstad
Keyword(s):  
Low Temperature ◽  
Metal Surface ◽  
Relative Velocity ◽  
Thermal Contact ◽  
High Rate ◽  
Rapid Freezing ◽  
Temperature Decrease ◽  
Freeze Etching

The importance of a high rate of temperature decrease (“rapid freezing”) when freezing specimens for freeze-etching has long been recognized1. The two basic methods for achieving rapid freezing are: 1) dropping the specimen onto a metal surface at low temperature, 2) bringing the specimen instantaneously into thermal contact with a liquid at low temperature and subsequently maintaining a high relative velocity between the liquid and the specimen. Over the last couple of years the first method has received strong renewed interest, particularily as the result of a series of important studies by Heuser and coworkers 2,3. In this paper we will compare these two freezing methods theoretically and experimentally.

Why the high rate of dropout from individualized cognitive-behavior therapy for bulimia nervosa?

2001 ◽  
Author(s):  
Z. Steel ◽  
J. Jones ◽  
S Adcock ◽  
R Clancy ◽  
L. Bridgford-West ◽  
...  
Keyword(s):  
Bulimia Nervosa ◽  
Behavior Therapy ◽  
Cognitive Behavior Therapy ◽  
High Rate ◽  
Cognitive Behavior

Pruned-trellis search technique for high-rate convolutional codes

1989 ◽  
Vol 136 (5) ◽  
pp. 405 ◽  
Author(s):  
J. Sun ◽  
I.S. Reed ◽  
H.E. Huey ◽  
T.K. Truong
Keyword(s):  
Convolutional Codes ◽  
High Rate ◽  
Search Technique
Sign in / Sign up

Export Citation Format

Share Document