THE RELATIONSHIP BETWEEN AUTHIGENIC KAOLINITE, RESERVOIR QUALITY AND TRAP HISTORY IN WONNICH-I

1997 ◽  
Vol 37 (1) ◽  
pp. 340
Author(s):  
J.M.V. Storey ◽  
P.M. Hillock
Keyword(s):  
Oil And Gas ◽  
Early Stage ◽  
Potassium Feldspar ◽  
Pore Throat ◽  
Water Breakthrough ◽  
Anomalous Zone ◽  
Pass Through ◽  
The Relationship ◽  
Petrographic Study ◽  
Interstitial Velocity

A significant decrease in permeability is seen within the oil and water legs of the Wonnich-1 oil and gas discovery well in TP/8, despite an increase in porosity of 4-5 per cent by volume. The anomalous zone contains abundant authigenic kaolinite. The prompt integration of wireline log and core data allowed the presence of this kaolinite to be postulated at an early stage in the appraisal of the well. It also led to the proposal that the authigenic kaolinite was derived through the dissolution of detrital potassium feldspar and that its distribution was related to a palaeo-hydrocarbon contact. This hypothesis was used to design a tailored special core analysis and petrographic study including fluid inclusion, mercury injection and critical velocity analyses. The results confirmed the model and indicate that the bulk of the additional porosity within the anomalous zone is microporosity. In addition, the results show that where water is the flowing phase, the authigenic kaolinite becomes mobile at an interstitial velocity of approximately 4.4 jim/s. This equates to a water offtake rate of 5,700 BWPD, making kaolinite movement in the immediate vicinity of the well bore likely in any Wonnich oil development scenario. Pore throat sizes in the Wonnich reservoir appear to be sufficiently large that the kaolinite will pass through leading to an increase in permeability rather than a decrease. As a consequence, kaolinite movement is likely to lead to an increase in water production since it will occur preferentially in areas of water breakthrough.

Locating Source of Water Production and Performing Cost-Effective Rigless Remedial Operations in Deviated Wells Completed with Standalone Sand Screens

2021 ◽  
Author(s):  
Andrey Timonin ◽  
Eldar Mollaniyazov
Keyword(s):  
Oil And Gas ◽  
Cost Effective ◽  
Water Production ◽  
Future Earnings ◽  
Oil And Gas Producers ◽  
Water Breakthrough ◽  
Sand Accumulation ◽  
Pass Through ◽  
Logging Tool ◽  
Deviated Wells

Abstract Wells that are already drilled and producing are the most viable sources of future earnings for all oilfield operating companies. Keeping these wells producing economically at optimal rates throughout their lifetimes is top priority. With time, some oilfield operating companies face with production related problems, such us water breakthrough. Production logging is well known technique for locating source of water breakthrough in oil and gas producers. In near-vertical, or slightly deviated wells, producing at high rates, traditional production logging tool string can deliver reliable results. On the other side, in deviated wells, producing at small rates, advanced production logging tool is required, due to presence of fluid segregation and recirculation within borehole. Our experience shows that wisely selected logging technique, depending on downhole logging environment, allows to locate source of water production with confidence for planning water shut-off remedial operations. In wells completed with standalone sand screens water shut-off operation might be complicated as often rig is required for pulling out of hole tubing with sand screens. Another method is to perform chemical water shut-off treatment that might be expensive in some cases. Alternative method is to confirm compact sand accumulation in the annulus and set through tubing bridge plug inside sand screens in wells that producing water from bottommost layers. Plug is deployed in wells without pulling out of hole tubing, as it can pass through restrictions, making this rigless intervention fifty times cheaper compared to intervention with rig. Field examples, presented in this paper, describe fit-for-purpose logging approach for locating source of water production accurately and executing unique rigless water shut-off operations in cased wells completed with standalone sand screens to increase hydrocarbons production in cost-effective way. After remedial operations we observed significant decline in water production and increase in oil rates in all wells that were intervened.

scholarly journals A mathematical model for leak location and leak area determination in pipeline networks

2013 ◽  
pp. 133-149
Author(s):  
O.I. Oyedokun ◽  
S.A. Oke ◽  
D.E. Ighravwe
Keyword(s):  
Oil And Gas ◽  
Simulated Data ◽  
Petroleum Products ◽  
Time Interval ◽  
Leak Location ◽  
Pipeline Networks ◽  
Location Detection ◽  
Pass Through ◽  
The Relationship ◽  
Area Determination

Prompt leak location and leak area determination in oil and gas pipeline installations is an indispensable approach to controlling petroleum products wastages in pipes. However, there is an evident lack of literature information on this subject. In this paper, we modelled leak location detection and leak area determination in pipes by applying two methodologies and gave an illustrative example using simulated data with the aid of Matlab. A comparison of these two approaches resulted in an error of 6.24%, suggesting that the closer the leak is to the measurement station, the lower will be the time interval between two successive waves that will pass through the leak and get to the measurement station. The relationship between the pipe area and coefficient of reflection is parabolic. This contribution is valuable to pipeline engineers in the economic control of leaks.

Interfacial Electrochemistry of Bond Cement and Tubular Steel

2011 ◽  
Vol 374-377 ◽  
pp. 53-56
Author(s):  
Cheng Qiang Ren ◽  
Lei Gao ◽  
Li Li ◽  
Ming Lin Guo
Keyword(s):  
Oil And Gas ◽  
Early Stage ◽  
Structure Change ◽  
Gas Wells ◽  
Bode Plot ◽  
Stability Change ◽  
Electrochemical Parameters ◽  
The Stability ◽  
Relationship Of ◽  
The Relationship

The stability of interface between bond cement and tubular steel is very important to the integrality of oil and gas wells. However, research on the degradation of the interface in aggressive solution is absent to date. This work devotes to discover the relationship of electrochemical parameters and interfacial development during early stage of corrosion by analyzing the electrochemical results. Dielectric spectroscopy obviously describes the stability change of passive film of steel, and Bode plot supports the structure change of cement. The early stage of immersion in aggressive solution is dominated by competition of hydratation and corrosion.

Radiation Damage, Contrast and Statistics in High Resolution Biological Electron Microscopy

1970 ◽  
Vol 28 ◽  
pp. 260-261
Author(s):  
Robert M. Glaeser
Keyword(s):  
High Resolution ◽  
Particle Flux ◽  
Unit Area ◽  
Signal To Noise ◽  
Resolution Image ◽  
High Resolution Image ◽  
Pass Through ◽  
Counting Statistics ◽  
The Relationship ◽  
Picture Element

It is well known that a large flux of electrons must pass through a specimen in order to obtain a high resolution image while a smaller particle flux is satisfactory for a low resolution image. The minimum particle flux that is required depends upon the contrast in the image and the signal-to-noise (S/N) ratio at which the data are considered acceptable. For a given S/N associated with statistical fluxtuations, the relationship between contrast and “counting statistics” is s131_eqn1, where C = contrast; r2 is the area of a picture element corresponding to the resolution, r; N is the number of electrons incident per unit area of the specimen; f is the fraction of electrons that contribute to formation of the image, relative to the total number of electrons incident upon the object.

scholarly journals COVID-19 uncertainty and sleep: the roles of perceived stress and intolerance of uncertainty during the early stage of the COVID-19 outbreak

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dan Wu ◽  
Tingzhong Yang ◽  
Daniel L. Hall ◽  
Guihua Jiao ◽  
Lixin Huang ◽  
...  
Keyword(s):  
Path Analysis ◽  
Perceived Stress ◽  
Mediation Analysis ◽  
Early Stage ◽  
Intolerance Of Uncertainty ◽  
Policy Implications ◽  
Self Report ◽  
Poor Sleep ◽  
The Relationship

Abstract Background The COVID-19 pandemic brings unprecedented uncertainty and stress. This study aimed to characterize general sleep status among Chinese residents during the early stage of the outbreak and to explore the network relationship among COVID-19 uncertainty, intolerance of uncertainty, perceived stress, and sleep status. Methods A cross-sectional correlational survey was conducted online. A total of 2534 Chinese residents were surveyed from 30 provinces, municipalities, autonomous regions of China and regions abroad during the period from February 7 to 14, 2020, the third week of lockdown. Final valid data from 2215 participants were analyzed. Self-report measures assessed uncertainty about COVID-19, intolerance of uncertainty, perceived stress, and general sleep status. Serial mediation analysis using the bootstrapping method and path analysis were applied to test the mediation role of intolerance of uncertainty and perceived stress in the relationship between uncertainty about COVID-19 and sleep status. Results The total score of sleep status was 4.82 (SD = 2.72). Age, place of residence, ethnicity, marital status, infection, and quarantine status were all significantly associated with general sleep status. Approximately half of participants (47.1%) reported going to bed after 12:00 am, 23.0% took 30 min or longer to fall asleep, and 30.3% slept a total of 7 h or less. Higher uncertainty about COVID-19 was significantly positively correlated with higher intolerance of uncertainty (r = 0.506, p < 0.001). The mediation analysis found a mediating role of perceived stress in the relationship between COVID-19 uncertainty and general sleep status (β = 0.015, 95%C.I. = 0.009–0.021). However, IU was not a significant mediator of the relationship between COVID-19 uncertainty and sleep (β = 0.009, 95%C.I. = − 0.002–0.020). Moreover, results from the path analysis further showed uncertainty about COVID-19 had a weak direct effect on poor sleep (β = 0.043, p < 0.05); however, there was a robust indirect effect on poor sleep through intolerance of uncertainty and perceived stress. Conclusions These findings suggest that intolerance of uncertainty and perceived stress are critical factors in the relationship between COVID-19 uncertainty and sleep outcomes. Results are discussed in the context of the COVID-19 pandemic, and practical policy implications are also provided.

scholarly journals Effect of number of medications and use of potentially inappropriate medications on frailty among early-stage older outpatients

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yuya Uragami ◽  
Kazuhiro Takikawa ◽  
Hajime Kareki ◽  
Koji Kimura ◽  
Kazuyuki Yamamoto ◽  
...  
Keyword(s):  
Early Stage ◽  
Linear Trend ◽  
Cross Sectional Study ◽  
Potentially Inappropriate Medications ◽  
Sectional Study ◽  
Antithrombotic Drugs ◽  
Cross Sectional ◽  
The Relationship ◽  
Inappropriate Medications ◽  
Frailty Score

Abstract Background Frailty is an urgent concern among an aging population worldwide. However, the relationship between frailty and number and types of medications has not been studied in detail among early-stage older patients, and it is unclear what prescriptions may have a role in preventing frailty. This study aimed to clarify the effects of number of medications and use of potentially inappropriate medications (PIMs) on frailty among early-stage older outpatients in Japan. Methods A cross-sectional study was undertaken. Frailty scores and medications of outpatients aged 65–74 years who regularly visited community pharmacies were investigated. Frailty scores were classified as 0 (non-frailty), 1–2 (pre-frailty), and ≥ 3 (frailty). The association between frailty and number of medications was analyzed by age and compared between PIM use and non-use groups. The proportion of patients who used PIMs was also analyzed by frailty score. Results Of 923 older outpatients, 49 (5.3%) and 318 (34.5%) patients had frailty and pre-frailty scores, respectively. The numbers of medications among patients with pre-frailty and frailty were significantly higher than among those with non-frailty (p <  0.001 for both). A similar increase was shown for PIM use groups aged 69–71 and 72–74 years, but not for the PIM use group aged 65–68 years and all groups without PIM use. An increasing linear trend was observed for the relationship between the proportion of patients who used any PIM, as well as some subcategories of PIMs (such as NSAIDs, benzodiazepines, loop diuretics and antithrombotic drugs) and frailty score. Conclusions Unnecessary medication use among early-stage older outpatients, especially patients aged ≥69 years who use PIMs and many medications, seems to be associated with frailty, but further research is needed to confirm these findings.

scholarly journals Anosognosia in People with Cognitive Impairment: Association with Cognitive Deficits and Behavioral Disturbances

2015 ◽  
Vol 5 (1) ◽  
pp. 42-50 ◽  
Author(s):  
Antonella De Carolis ◽  
Virginia Cipollini ◽  
Valentina Corigliano ◽  
Anna Comparelli ◽  
Micaela Sepe-Monti ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Cognitive Deficits ◽  
Rating Scale ◽  
Motor Behavior ◽  
Psychiatric Symptoms ◽  
Early Stage ◽  
Functional Anatomy ◽  
Night Time ◽  
Behavioral Disturbances ◽  
The Relationship

Aims: To investigate, in a group of subjects at an early stage of cognitive impairment, the relationship between anosognosia and both cognitive and behavioral symptoms by exploring the various domains of insight. Methods: One hundred and eight subjects affected by cognitive impairment were consecutively enrolled. The level of awareness was evaluated by means of the Clinical Insight Rating Scale (CIRS). Psychiatric symptoms were evaluated using the Italian version of the Neuropsychiatric Inventory (NPI), whereas memory (memory index, MI) and executive (executive index, EI) functions were explored using a battery of neuropsychological tests and qualified by means of a single composite cognitive index score for each function. Results: A significant positive correlation between the total NPI score and global anosognosia score was found. Furthermore, both the MI and EI scores were lower in subjects with anosognosia than in those without anosognosia (p < 0.001 and p < 0.007, respectively). When the single domains of the CIRS were considered, anosognosia of reason of visit correlated with the EI score (r = -0.327, p = 0.01) and night-time behavioral disturbances (r = 0.225; p = 0.021); anosognosia of cognitive deficit correlated with depression (r = -0.193; p = 0.049) and the MI score (r = -0.201; p = 0.040); anosognosia of functional deficit correlated with the MI score (r = -0.257; p = 0.008), delusions (r = 0.232; p = 0.015) and aberrant motor behavior (r = 0.289; p = 0.003); anosognosia of disease progression correlated with the MI score (r = -0.236; p = 0.015), agitation (r = 0.247; p = 0.011), aberrant motor behavior (r = 0.351; p = 0.001) and night-time behavioral disturbances (r = 0.216; p = 0.027). Conclusions: Our study suggests that, in the early stage of cognitive impairment, anosognosia is associated with both cognitive deficits and behavioral disorders according to the specific functional anatomy of the symptoms.

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