Use of the NMR and Resistivity Logs to Quantify Movable Hydrocarbon; Solution for the Tight and Low-Resistivity Carbonate Reservoirs

2011 ◽  
Author(s):  
Mohammadhossein Mohammadlou ◽  
Helge Langeland ◽  
Mai Britt Mørk
Keyword(s):  
Carbonate Reservoirs ◽  
Low Resistivity ◽  
Resistivity Logs ◽  
Hydrocarbon Solution

Developed Approach for Better Understanding of Low Resistivity Pay Carbonate Reservoirs

2010 ◽  
Author(s):  
Adel Obeidi ◽  
Fatema Mohamed Al Aryani ◽  
Mohsen Ahmed Al Amoudi
Keyword(s):  
Carbonate Reservoirs ◽  
Low Resistivity

The Application of Maine Petrophysical Method; Adding Resources by Explore the Opportunity in Low Resistivity Pay Reservoir

2021 ◽  
Author(s):  
Mohammad Reza ◽  
Riezal Arieffiandhany ◽  
Debby Irawan ◽  
S Shofiyuddin ◽  
Darmawan Budi Prihanto
Keyword(s):  
High Resolution ◽  
Transition Zone ◽  
Water Saturation ◽  
Electrical Parameter ◽  
Parameter Determination ◽  
Type Curve ◽  
Petrophysical Analysis ◽  
Low Resistivity ◽  
Resistivity Logs ◽  
Shaly Sand

Abstract Manifestation of Low Resistivity Pay (LRP) Existences in ONWJ Area because of Fine Grained, Superficial Microporosity, Laminated Shaly Sand and Electronic Conduction. Water saturation petrophysical analysis for LRP Case due to those reason above can be solved by electrical parameter determination with Type Curve. But to overcome the LRP caused by Laminated Shaly Sand, the use of high resolution resistivity logs that are close to the resolution of thin bed reservoir is a must. Alternative solutions, conventional high resolution resistivity logs, namely Micro Spherical Focused Log (MSFL) are used to interpret thin bed reservoirs that have the hydrocarbon potential. This intergrated petrophysical analysis is called MAINE Petrophysical Method The Petrophysical MAINE method is the development of the TECWAL (Type Curve, Core and Water Analysis) method which leaves question marks on Laminated Shaly Sand Reservoir and the possibility of variations in the Electrical Parameter and Water Saturation Irreducible (SWIRR) dependent on Rocktype. The Basis of the MAINE Method is the Worthington Type Curve with some assumptions such as Each rocktype has a different value of Bulk Volume of Water (BVW) and BVW can be used to determine the SWIRR value of each rocktype and Each rocktype has different electrical parameter m and n. In the process, the use of J-Function and Buckles Plot is applied to help determinet Rocktype and BVW values. The rocktype will be the media in distributing the value of Electrical Parameter generated by the Type Curve and the value will be used in water saturation calculation. In Laminated Shaly Sand Reservoir, Rocktyping will be analyzed more detail using the High Resolution Conventional Log, Micro Spherical Focused Log (MSFL). The expected final result of this analysis is the more reliable Water Saturation (SW) and the integration of water saturation values in the Buckles Plot which can help in determining the transition zone in order to avoid mistakes in determining the perforation zone. Through the MAINE Petrophysical Method, there is a decrease in water saturation from an average value 86% to 66% or a decrease 23%. This result is quite significant for the calculation of reserves in the LRP zone. By integrating this method with the Buckles Plot, it can help the interpreter to determine the perforation interval in order to avoid water contact or the transition zone

scholarly journals Challenge of Water Saturation in Low Resistivity Cretaceous Reservoirs

2018 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Water Saturation ◽  
Size Variation ◽  
Pulse Neutron ◽  
Specific Resistivity ◽  
Pore Throat ◽  
Low Resistivity ◽  
Texture Change ◽  
Carbonate Deposit ◽  
Resistivity Logs ◽  
Carbonate Deposits

This study presents causes and reasons for lowering resistivity logs in carbonate deposit. Moreover this abstract elucidate methods for relieving of challenge water saturation estimation in cretaceous carbonate deposits with Low Resistivity Pay, in Persian Gulf. Reservoirs in the Cretaceous like Zubair, Buwaib, Shuaiba and Khatiyah formations of Southern fields have been analyzed as low resistivity carbonate. Resistivity responses reach less than 6 and even less than 1 ohm.m. Significant hydrocarbon accumulations are “hidden” these Pay zone, (LRPZ). Experimental analysis shows that reservoirs contain clay-coated grains of Lithocodyum algal and is along with Micrtization, Pyritization of digenetic process are reasons for effect on resistivity response. On the other side Smectite and Kaolinite of main clays types have high CEC and greater impact on lowering resistivity. Lønøy method applied to address pore throat sizes which contain Inter crystalline porosity, Chalky Limestone, Mudstone micro porosity. NMR (Nuclear magnetic resonance and Pulse Neutron-Neutron logs have been used to modify the calculated water saturation of the wells. The study shows that reduced specific resistivity is due to texture change and presence of microscopic porosity. For defining reliable water saturation, Core NMR and Log NMR results have been used. NMR results explain that decreasing of resistivity in pay zone is related to texture and grain size variation not being existence of moved water. Irreducible water for the reservoirs is estimated between 30 to 50 %. Low resistivity zone related to microspores with less than 3 micron. Variable T2 cut off is allows to choice suitable T2 cut off values to differentiate movable from bound fluids adapted for the specific carbonate rock. T2 cut off varies between 45 to 110ms. The proper T2 cut off for these formations are extremely crucial to being able to estimate permeability and water saturation.

VERY LOW RESISTIVITY AuMn GATE OHMIC CONTACTS FOR GaInAs DIFFUSED JFETs

1988 ◽  
Vol 49 (C4) ◽  
pp. C4-453-C4-456 ◽  
Author(s):  
P. E. HALLALI ◽  
P. BLANCONNIER ◽  
L. BRICARD ◽  
J-C. RENAUD
Keyword(s):  
Ohmic Contacts ◽  
Low Resistivity

Integration of Multi-geophysical Approaches to Identify Potential Pathways of Heavy Metals Contamination - A Case Study in Zeida, Morocco

2020 ◽  
Vol 25 (3) ◽  
pp. 415-423
Author(s):  
Ahmed Lachhab ◽  
El Mehdi Benyassine ◽  
Mohamed Rouai ◽  
Abdelilah Dekayir ◽  
Jean C. Parisot ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Seismic Velocity ◽  
Seismic Refraction ◽  
Geophysical Methods ◽  
Low Frequency ◽  
Electrical Current ◽  
P Wave ◽  
Low Resistivity ◽  
Refraction Tomography ◽  
Geophysical Surveys

The tailings of Zeida's abandoned mine are found near the city of Midelt, in the middle of the high Moulouya watershed between the Middle and the High Atlas of Morocco. The tailings occupy an area of about 100 ha and are stored either in large mining pit lakes with clay-marl substratum or directly on a heavily fractured granite bedrock. The high contents of lead and arsenic in these tailings have transformed them into sources of pollution that disperse by wind, runoff, and seepage to the aquifer through faults and fractures. In this work, the main goal is to identify the pathways of contaminated water with heavy metals and arsenic to the local aquifers, water ponds, and Moulouya River. For this reason, geophysical surveys including electrical resistivity tomography (ERT), seismic refraction tomography (SRT) and very low-frequency electromagnetic (VLF-EM) methods were carried out over the tailings, and directly on the substratum outside the tailings. The result obtained from combining these methods has shown that pollutants were funneled through fractures, faults, and subsurface paleochannels and contaminated the hydrological system connecting groundwater, ponds, and the river. The ERT profiles have successfully shown the location of fractures, some of which extend throughout the upper formation to depths reaching the granite. The ERT was not successful in identifying fractures directly beneath the tailings due to their low resistivity which inhibits electrical current from propagating deeper. The seismic refraction surveys have provided valuable details on the local geology, and clearly identified the thickness of the tailings and explicitly marked the boundary between the Triassic formation and the granite. It also aided in the identification of paleochannels. The tailings materials were easily identified by both their low resistivity and low P-wave velocity values. Also, both resistivity and seismic velocity values rapidly increased beneath the tailings due to the compaction of the material and lack of moisture and have proven to be effective in identifying the upper limit of the granite. Faults were found to lie along the bottom of paleochannels, which suggest that the locations of these channels were caused by these same faults. The VLF-EM surveys have shown tilt angle anomalies over fractured areas which were also evinced by low resistivity area in ERT profiles. Finally, this study showed that the three geophysical methods were complementary and in good agreement in revealing the pathways of contamination from the tailings to the local aquifer, nearby ponds and Moulouya River.

Efficiency improvement of foam-acid treatments and selective large-volume acidizing at carbonate reservoirs of Tatneft PJSC

2019 ◽  
Vol 11 ◽  
pp. 116-119
Author(s):  
M.Kh. Musabirov ◽  
◽  
A.Yu. Dmitrieva ◽  
R.F. Khusainov ◽  
E.M. Abusalimov ◽  
...  
Keyword(s):  
Large Volume ◽  
Carbonate Reservoirs ◽  
Efficiency Improvement ◽  
Acid Treatments
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