Experimental Study on Sensitivity Damage of Offshore High-Porosity and High-Permeability Reservoir

2014 ◽  
Vol 926-930 ◽  
pp. 111-114
Author(s):  
Jun Yi Liu ◽  
Zheng Song Qiu ◽  
Wei An Huang ◽  
Yang Luo
Keyword(s):  
Experimental Studies ◽  
Wide Distribution ◽  
Development Stage ◽  
Stress Sensitivity ◽  
Laboratory Evaluation ◽  
Drilling Fluids ◽  
High Porosity ◽  
High Permeability ◽  
Intrusion Prevention ◽  
Water Sensitivity

Offshore high-porosity and high-permeability reservoirs, characterized by large pore throat, wide distribution of pore size and enriched sensitive minerals, are easily damaged due to improper use of drilling fluids and completion fluids during the development stage. A series of experimental studies were carried out on the sensitivity damage analysis including X-ray diffraction, scanning electron microscopy, mercury injection porosimetry and core flow experiment. According to the laboratory evaluation results, the reservoir SZLF of high-porosity and high-permeability existed strong water sensitivity and mid to strong stress sensitivity. Furthermore, shielding and temporary plugging technique applied for reservoir protection was put forward, and laboratory tests showed that it had a better effect on solid intrusion prevention.

scholarly journals An FYVE-Domain-Containing Protein, PsFP1, Is Involved in Vegetative Growth, Oxidative Stress Response and Virulence of Phytophthora sojae

2021 ◽  
Vol 22 (12) ◽  
pp. 6601
Author(s):  
Jinhui Zhang ◽  
Xiaoran Du ◽  
Xin Zhou ◽  
Duo Jin ◽  
Jianqiang Miao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Membrane Trafficking ◽  
Vegetative Growth ◽  
Genome Mining ◽  
Gene Replacement ◽  
Wide Distribution ◽  
Stress Sensitivity ◽  
Phytophthora Sojae ◽  
Knock Out ◽  
Fyve Domain

Proteins that contain the FYVE zinc-finger domain are recruited to PtdIns3P-containing membranes, participating in numerous biological processes such as membrane trafficking, cytoskeletal regulation, and receptor signaling. However, the genome-wide distribution, evolution, and biological functions of FYVE-containing proteins are rarely reported for oomycetes. By genome mining of Phytophthora sojae, two proteins (PsFP1 and PsFP2) with a combination of the FYVE domain and the PX domain (a major phosphoinositide binding module) were found. To clarify the functions of PsFP1 and PsFP2, the CRISPR/Cas9-mediated gene replacement system was used to knock out the two genes respectively. Only heterozygous deletion mutants of PsFP1 were recovered, and the expression level of PsFP1 in the heterozygous knockout transformants was significantly down-regulated. These PsFP1 mutants showed a decrease in mycelial growth and pathogenicity and were more sensitive to hydrogen peroxide. These phenotypes were recovered to the level of wild-type by overexpression PsFP1 gene in the PsFP1 heterozygous knockout transformant. In contrast, deletion of PsFP2 had no significant effect on vegetative growth, asexual and sexual reproduction, pathogenicity, or oxidative stress sensitivity. PsFP1 was primarily localized in vesicle-like structures and both the FYVE and PX domains are important for its localization. Overall, our results indicate that PsFP1 plays an important role in the vegetative growth and virulence of P. sojae.

Redevelopment of a Matured Multilayered Carbonate Offshore Field Through High Technology Horizontal and Multilateral Wells

2007 ◽  
Vol 10 (05) ◽  
pp. 453-457 ◽  
Author(s):  
Rajesh Kumar ◽  
S. Ramanan ◽  
J.L. Narasimham
Keyword(s):  
New Technologies ◽  
High Technology ◽  
Horizontal Wells ◽  
Development Stage ◽  
Scientific Data ◽  
Carbonate Reservoir ◽  
Western India ◽  
Drilling Fluids ◽  
Well Productivity ◽  
Offshore Field

Summary Oil productivity from Mumbai High field, an offshore multilayered carbonate reservoir, increased significantly through the implementation of a major redevelopment program. Geoscientific information available from approximately 700 exploratory and develop- ment wells drilled in the field during nearly 25 years was incorporated during geological and reservoir simulation modeling of the field. High-technology drilling (viz. horizontal/multilaterals for the new development wells) was adopted on field scale to effectively address typical complexity of the layered carbonate reservoirs. Since the commencement of the project in 2000, approximately 140 new wells were drilled, mostly with horizontal and multilateral drainholes. Besides these, more than 70 suboptimal producers were also converted as horizontal sidetracks under brownfield development. The horizontal sidetracks were drilled as long-drift sidetrack (LDST), extended-reach drilling (ERD), LDST-ERD, short-drift sidetrack (SDST), and medium-radius drainhole (MRDH) types of wells through the application of innovative and emerging drilling technologies with nondamaging drilling fluids, whipstocks to kick off sidetrack wells, rotary-steering systems, and expandable tubulars to complete horizontal sidetracks in lower layers. With the implementation of this project, the declining trend was fully arrested and a significant upward trend in production has been established. Introduction The field redevelopment process requires the intergration of reservoir-development strategies, facility options, and drilling and production philosophies to maximize oil and gas recovery from a matured field. A significant number of case studies are available on mature field revitalization using a multidisciplinary team concept, exhaustive geo-scientific data analysis, and new drilling technologies (Chedid and Colmenares 2002; Clark et al. 2000; Dollens et al. 1999; Kinchen et al. 2001). Advancements in drilling and completion technology have enabled construction of horizontal wells with longer wellbores, more-complex well geometry, and sophisticated completion designs. Horizontal wells provide an effective method to produce bypassed oil from matured fields. In the early 1980s, this technology was in the development stage and was used in limited applications. By the 1990s, the technology had matured, and its acceptance in the industry had increased significantly. Performance of horizontal/multilateral wells, risk assessment of horizontal-well productivity and comparison of horizontal- and vertical-well performance in different fields is available in literature (Babu and Aziz 1989; Brekke and Thompson 1996; Economides et al. 1989; Joshi 1987; Joshi and Ding 1995; Mukherjee and Economides 1991; Norris et al. 1991; Vij et al. 1998). A significant number of horizontal/multilateral development wells were drilled as a part of redevelopment of Mumbai High, a matured multilayered carbonate offshore field in Western India. The details of new technologies applied and performance of these new high-technology wells are presented in this paper. Besides comparison of well productivity of horizontal and conventional sidetrack wells, this paper presents some technical issues faced.

scholarly journals Novel glucose-responsive of the transparent nanofiber hydrogel patches as a wearable biosensor via electrospinning

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Gun Jin Kim ◽  
Kyu Oh Kim
Keyword(s):  
Continuous Monitoring ◽  
Interstitial Fluid ◽  
High Sensitivity ◽  
Poly Vinyl Alcohol ◽  
High Porosity ◽  
High Permeability ◽  
Reverse Iontophoresis ◽  
Glucose Levels ◽  
Non Invasive ◽  
High Enzyme

Abstract Micro- and nanofiber (NF) hydrogels fabricated by electrospinning to typically exhibit outstanding high porosity and specific surface area under hydrated conditions. However, the high crystallinity of NFs limits the achievement of transparency via electrospinning. Transparent poly(vinyl alcohol)/β-cyclodextrin polymer NF hydrogels contacted with reverse iontophoresis electrodes were prepared for the development of a non-invasive continuous monitoring biosensor platform of interstitial fluid glucose levels reaching ~ 1 mM. We designed the PVA/BTCA/β-CD/GOx/AuNPs NF hydrogels, which exhibit flexibility, biocompatibility, excellent absorptivity (DI water: 21.9 ± 1.9, PBS: 41.91 ± 3.4), good mechanical properties (dried: 12.1 MPa, wetted: 5.33 MPa), and high enzyme activity of 76.3%. Owing to the unique features of PVA/β-CD/GOx containing AuNPs NF hydrogels, such as high permeability to bio-substrates and rapid electron transfer, our biosensors demonstrate excellent sensing performance with a wide linear range, high sensitivity(47.2 μA mM−1), low sensing limit (0.01 mM), and rapid response time (< 15 s). The results indicate that the PVA/BTCA/β-CD/GOx/AuNPs NF hydrogel patch sensor can measure the glucose concentration in human serum and holds massive potential for future clinical applications.

Stress sensitivity of sandstones

Geophysics ◽  
1996 ◽  
Vol 61 (2) ◽  
pp. 444-455 ◽  
Author(s):  
Jack Dvorkin ◽  
Amos Nur ◽  
Caren Chaika
Keyword(s):  
Elastic Modulus ◽  
Effective Stress ◽  
Elastic Moduli ◽  
Hydrostatic Stress ◽  
Clay Content ◽  
Stress Sensitivity ◽  
High Porosity ◽  
Effective Pressure ◽  
Critical Porosity ◽  
Difference Formula

Our observations made on dry‐sandstone ultrasonic velocity data relate to the variation in velocity (or modulus) with effective stress, and the ability to predict a velocity for a rock under one effective pressure when it is known only under a different effective pressure. We find that the sensitivity of elastic moduli, and velocities, to effective hydrostatic stress increases with decreasing porosity. Specifically, we calculate the difference between an elastic modulus, [Formula: see text], of a sample of porosity ϕ at effective pressure [Formula: see text] and the same modulus, [Formula: see text], at effective pressure [Formula: see text]. If this difference, [Formula: see text], is plotted versus porosity for a suite of samples, then the scatter of ΔM is close to zero as porosity approaches the critical porosity value, and reaches its maximum as porosity approaches zero. The dependence of this scatter on porosity is close to linear. Critical porosity here is the porosity above which rock can exist only as a suspension—between 36% and 40% for sandstones. This stress‐sensitivity pattern of grain‐supported sandstones (clay content below 0.35) practically does not depend on clay content. In practical terms, the uncertainty of determining elastic moduli at a higher effective stress from the measurements at a lower effective stress is small at high porosity and increases with decreasing porosity. We explain this effect by using a combination of two heuristic models—the critical porosity model and the modified solid model. The former is based on the observation that the elastic‐modulus‐versus‐porosity relation can be approximated by a straight line that connects two points in the modulus‐porosity plane: the modulus of the solid phase at zero porosity and zero at critical porosity. The second one reflects the fact that at constant effective stress, low‐porosity sandstones (even with small amounts of clay) exhibit large variability in elastic moduli. We attribute this variability to compliant cracks that hardly affect porosity but strongly affect the stiffness. The above qualitative observation helps to quantitatively constrain P‐ and S‐wave velocities at varying stresses from a single measurement at a fixed stress. We also show that there are distinctive linear relations between Poisson’s ratios (ν) of sandstone measured at two different stresses. For example, in consolidated medium‐porosity sandstones [Formula: see text], where the subscripts indicate hydrostatic stress in MPa. Linear functions can also be used to relate the changes (with hydrostatic stress) in shear moduli to those in compressional moduli. For example, [Formula: see text], where [Formula: see text] is shear modulus and [Formula: see text] is compressional modulus, both in GPa, and the subscripts indicate stress in MPa.

scholarly journals The Use of Agricultural Waste Straw to Enhance Loess Shearing Behaviour: An Experimental Investigation

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Lin Wang ◽  
Wen-Chieh Cheng ◽  
Zhong-Fei Xue
Keyword(s):  
Triaxial Compression ◽  
Agricultural Waste ◽  
Loess Soil ◽  
Stress Path ◽  
Northwest China ◽  
High Porosity ◽  
Stress Strain ◽  
Water Sensitivity ◽  
Strain Relation ◽  
Stress Strain Relation

Strata erosion in northwest China has become an engineering concern as a result of overdevelopment of land. This issue is more distinct for loess soil than other soils since it is characterised by metastable microstructure, high porosity, and water sensitivity. This study explores the potential for the use of agricultural waste straw as a recycled reinforcement material to form the enhanced shearing behaviour towards preventing instability of the loess body. The stress-strain relation and the pore pressure behaviour of Lantian loess and reinforced Lantian loess were studied using the conventional triaxial compression (CTC) stress path for three different confining pressures. Comparison with Jingyang loess and Delhi silt of similar relative fraction of silt to clay, sheared under the reduced triaxial compression (RTC) stress path and the reduced triaxial extension (RTE) stress paths, respectively, was conducted, with emphasis on strength uniqueness and critical state behaviour, to shed light on the effect of waste straw inclusions. The results indicate that the stress path in undrained compression and extension tests had a pronounced effect on the stress-strain relation of the studied soils. Insertion of the waste straw in Lantian loess restrained the development of volumetric deformation, producing higher pore pressures than Lantian loess (unreinforced). This study explores an exciting potential for the use of agricultural waste straw to prevent instability of the loess body in hilly-gullied regions of northwest China when subjected to quick surface thick fills.

scholarly journals Laboratory Evaluation of Eco-Friendly Pervious Concrete Pavement Material Containing Silica Fume

2018 ◽  
Vol 9 (1) ◽  
pp. 73 ◽  
Author(s):  
Hanbing Liu ◽  
Guobao Luo ◽  
Longhui Wang ◽  
Wensheng Wang ◽  
Wenjun Li ◽  
...  
Keyword(s):  
Silica Fume ◽  
Pervious Concrete ◽  
Laboratory Evaluation ◽  
High Porosity ◽  
Supplementary Cementitious Material ◽  
Freeze Thaw ◽  
Replacement Method ◽  
Concrete Mixtures ◽  
Porosity And Permeability ◽  
Volume Method

Pervious concretes, such as sustainable pavement materials, have great advantages in solving urban flooding, promoting urban ecological balance, and alleviating urban heat island effect, due to its special porous structure. However, pervious concrete typically has high porosity and low strength. The insufficient strength and poor freeze-thaw durability are important factors that restrict its wide application, especially in seasonal frozen areas. Improving the strength and freeze-thaw resistance of pervious concrete will expand its application. Silica fumes, as an industrial by-product waste and supplementary cementitious material, play an important role in improving concrete performance. The objective of this paper was to study the effects of silica fumes on properties of sustainable pervious concrete. Silica fumes were used to replace cement with the equivalent volume method at different levels (3%, 6%, 9%, and 12%). The control pervious concrete and silica fume-modified pervious concrete mixtures were prepared in the lab. The porosity, permeability, compressive strength, flexural strength, and freeze-thaw resistance properties of all mixtures were tested. The results indicated that the addition of silica fumes significantly improved the strength and freeze-thaw resistance of pervious concrete. The porosity and permeability of all pervious concrete mixtures changed little with the content of silica fumes due to the adoption of the equal volume replacement method.

Seismic monitoring of a CO2 flood in a carbonate reservoir: A rock physics study

Geophysics ◽  
1998 ◽  
Vol 63 (5) ◽  
pp. 1604-1617 ◽  
Author(s):  
Zhijing Wang ◽  
Michael E. Cates ◽  
Robert T. Langan
Keyword(s):  
High Resolution ◽  
Pore Pressure ◽  
Rock Physics ◽  
Fluid Substitution ◽  
High Porosity ◽  
High Permeability ◽  
Pressure Buildup ◽  
Reservoir Rocks ◽  
Velocity Changes

A carbon dioxide (CO2) injection pilot project is underway in Section 205 of the McElroy field, West Texas. High‐resolution crosswell seismic imaging surveys were conducted before and after CO2 flooding to monitor the CO2 flood process and map the flooded zones. The velocity changes observed by these time‐lapse surveys are typically on the order of −6%, with maximum values on the order of −10% in the vicinity of the injection well. These values generally agree with laboratory measurements if the effects of changing pore pressure are included. The observed dramatic compressional ([Formula: see text]) and shear ([Formula: see text]) velocity changes are considerably greater than we had initially predicted using the Gassmann (1951) fluid substitution analysis (Nolen‐Hoeksema et al., 1995) because we had assumed reservoir pressure would not change from survey to survey. However, the post‐CO2 reservoir pore fluid pressure was substantially higher than the original pore pressure. In addition, our original petrophysical data for dry and brine‐saturated reservoir rocks did not cover the range of pressures actually seen in the field. Therefore, we undertook a rock physics study of CO2 flooding in the laboratory, under the simulated McElroy pressures and temperature. Our results show that the combined effects of pore pressure buildup and fluid substitution caused by CO2 flooding make it petrophysically feasible to monitor the CO2 flood process and to map the flooded zones seismically. The measured data show that [Formula: see text] decreases from a minimum 3.0% to as high as 10.9%, while [Formula: see text] decreases from 3.3% to 9.5% as the reservoir rocks are flooded with CO2 under in‐situ conditions. Such [Formula: see text] and [Formula: see text] decreases, even if averaged over all the samples measured, are probably detectable by either crosswell or high‐resolution surface seismic imaging technologies. Our results show [Formula: see text] is sensitive to both the CO2 saturation and the pore pressure increase, but [Formula: see text] is particularly sensitive to the pore pressure increase. As a result, the combined [Formula: see text] and [Formula: see text] changes caused by the CO2 injection may be used, at least semiquantitatively, to separate CO2‐flooded zones with pore pressure buildup from those regions without pore pressure buildup or to separate CO2 zones from pressured‐up, non‐CO2 zones. Our laboratory results show that the largest [Formula: see text] and [Formula: see text] changes caused by CO2 injection are associated with high‐porosity, high‐permeability rocks. In other words, CO2 flooding and pore pressure buildup decrease [Formula: see text] and [Formula: see text] more in high‐porosity, high‐permeability samples. Therefore, it may be possible to delineate such high‐porosity, high‐permeability streaks seismically in situ. If the streaks are thick enough compared to seismic resolution, they can be identified by the larger [Formula: see text] or [Formula: see text] changes.

DYNAMIC COMPRESSIBILITY OF HIGH-POROSITY DAMPERS OF THERMAL AND SHOCK LOADINGS: MODELING AND EXPERIMENT

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1183-1188 ◽  
Author(s):  
ANATOLY BRAGOV ◽  
ALEXANDER KONSTANTINOV ◽  
ANDREY LOMUNOV ◽  
ANATOLY SADYRIN ◽  
IVAN SERGEICHEV ◽  
...  
Keyword(s):  
Dynamic Properties ◽  
Porous Ceramic ◽  
Experimental Studies ◽  
Ceramic Materials ◽  
Heat Of Fusion ◽  
High Porosity ◽  
Dynamic Compressibility ◽  
Damping Materials ◽  
The Mathematical Model ◽  
Highly Porous

High-porosity materials, such as chamotte and mullite, possess a heat of fusion. Owing to their properties, these materials can be used with success as damping materials in containers for airplane, automobile, etc. transportation of radioactive or highly toxic materials. Experimental studies of the dynamic properties have been executed with using some original modifications of the Kolsky method. These modified experiments have allowed studying the dynamic compressibility of high-porosity chamotte at deformations up to 80% and amplitudes up to 50 MPa. The equations of the mathematical model describing shock compacting of chamotte as a highly porous, fragile, collapsing material are presented. Deformation of high-porous materials at non-stationary loadings is usually accompanied by fragile destruction of interpore partitions as observed in other porous ceramic materials. Comparison of numerical and experimental results has shown their good conformity.

Research on Stress Sensitivity of Low Permeability Sand Stone Reservoir

2011 ◽  
Vol 317-319 ◽  
pp. 2432-2435
Author(s):  
Yu Xue Sun ◽  
Fei Yao ◽  
Jing Yuan Zhao
Keyword(s):  
Plastic Deformation ◽  
In Situ Stress ◽  
Stress Sensitivity ◽  
Oil Field ◽  
Low Permeability ◽  
High Permeability ◽  
Permeability Changes ◽  
Loading And Unloading ◽  
Sandstone Reservoir

In the process of low-permeability sandstone reservoir exploitation, stress sensitivity takes place with the effective stress rises gradually, which will cause permeability decline. Allowing to the condition of in-situ stress, the study and experiment on the rock core in Jilin oil field Fuxin326 oil layer are presented. The experimental results show that the stress sensitivity of this oil layer is small; the regularity of permeability changes is in accordance with exponential function. The stress sensitivity of high permeability core is larger than that of low permeability core. Moreover, experimental and theoretical analysis shows that low permeability core has a larger permeability loss than high permeability core in loading and unloading process where elastic plastic deformation of rock will happen, which is the major reason that permeability loss can not return completely.

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