scholarly journals WELL LOG DATA INTERPRETATION PROBLEMS IN WELL, DRILLED USING POLYMER-CLAY-BASED DRILLING MUD

2017 ◽  
pp. 47-53
Author(s):  
G. E. Stroyanetskaya ◽  
E. A. Malykh
Keyword(s):  
Small Volume ◽  
High Salinity ◽  
Data Interpretation ◽  
Well Log ◽  
Drilling Mud ◽  
Electrical Measurements ◽  
Induction Method ◽  
The Core ◽  
Low Efficiency ◽  
Different Thickness

There was shown the low efficiency of standard well logging sequence for reservoirs identification and de-fining their saturation in the well, penetrating on polymer-clay-based drilling mud the section with high salinity of formation water. At low resistances of formations the reliable results of testing as for large volume reservoirs as well as for small volume reservoirs are needed for establishing the critical values of indications of induction method and electrical measurements against the permeable formations of different thickness. To distinguish the reservoirs it is necessary to obtain the core samples and to analyze them to establish the compliance of indications between geophysical measurements and reservoir characteristics.

scholarly journals WELL LOG DATA INTERPRETATION IN PALEOGEOGRAPHIC RECONSTRUCTIONS (IN THE CASE OF THE BATHONIAN-UPPER JURASSIC DEPOSITS OF SOUTH OF WEST SIBERIA)

2019 ◽  
pp. 27-38
Author(s):  
P. A. Yan ◽  
E. M. Khabarov
Keyword(s):  
Oil And Gas ◽  
West Siberia ◽  
Data Interpretation ◽  
Upper Jurassic ◽  
Well Log ◽  
The South ◽  
The West ◽  
Log Data ◽  
The Core

According to the results of a comprehensive sedimentological study of the core and well log data, the dissection of the bat-upper Jurassic sediments of the South of the West Siberian oil and gas basin was carried out. Quasi-isochronous marked levels are identified. They are represented by transgressive surfaces, maximum flooding surfaces and extended carbonaceous layers. They are the basis of the performed correlation. A number of characteristic lithological-facies sequences diagnosed by well log data was established.

Laterally accreted deposits in low efficiency turbidites associated with a structurally-induced topography (Oligocene Molare Group, Tertiary Piedmont Basin, NW Italy)

2021 ◽  
Vol 91 (7) ◽  
pp. 751-772
Author(s):  
Roberto Tinterri ◽  
Andrea Civa
Keyword(s):  
Small Volume ◽  
Alternative Interpretation ◽  
Meandering Channels ◽  
Stratigraphic Framework ◽  
Sediment Gravity Flow ◽  
Dense Flows ◽  
Low Efficiency ◽  
Nw Italy ◽  
Cross Current ◽  
Lateral Deflections

ABSTRACT The origin of laterally accreted deposits in ancient deep marine successions is often controversial. Indeed, not always do these features imply the occurrence of meanders or high-sinuosity turbidite channels, but they can be generated by other causes, such as sediment-gravity-flow dynamics controlled by the morphology of tectonically confined mini-basins. This work discusses laterally accreted deposits composed of sharp-based, normally graded beds in a very small tectonically controlled mini-basin. These beds, characterized by a well-defined asymmetrical cross-current facies tract, form well-developed lateral-accretion surfaces dipping in directions ranging between W and SW, and perpendicular to the paleocurrents directed towards the N. For this reason, these deposits have always been interpreted as point bars related to meandering channels. A new detailed stratigraphic framework and facies analysis have led to an alternative interpretation, namely that these deposits record lateral deflections of small volume, longitudinally segregated turbidite dense flows against a structurally controlled morphological high. This interpretation is also supported by a comparison to other tectonically controlled turbidite systems that are characterized by higher degrees of efficiency but show similar laterally accreted deposits and cross-current facies tracts.

scholarly journals Modification of Xanthan Gum for a High-Temperature and High-Salinity Reservoir

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4212
Author(s):  
Mohamed Said ◽  
Bashirul Haq ◽  
Dhafer Al Shehri ◽  
Mohammad Mizanur Rahman ◽  
Nasiru Salahu Muhammed ◽  
...  
Keyword(s):  
High Temperature ◽  
Oil Recovery ◽  
Xanthan Gum ◽  
Elevated Temperatures ◽  
High Salinity ◽  
Residual Oil ◽  
Core Flooding ◽  
Nacl Solution ◽  
The Core ◽  
Tertiary Oil Recovery

Tertiary oil recovery, commonly known as enhanced oil recovery (EOR), is performed when secondary recovery is no longer economically viable. Polymer flooding is one of the EOR methods that improves the viscosity of injected water and boosts oil recovery. Xanthan gum is a relatively cheap biopolymer and is suitable for oil recovery at limited temperatures and salinities. This work aims to modify xanthan gum to improve its viscosity for high-temperature and high-salinity reservoirs. The xanthan gum was reacted with acrylic acid in the presence of a catalyst in order to form xanthan acrylate. The chemical structure of the xanthan acrylate was verified by FT-IR and NMR analysis. The discovery hybrid rheometer (DHR) confirmed that the viscosity of the modified xanthan gum was improved at elevated temperatures, which was reflected in the core flood experiment. Two core flooding experiments were conducted using six-inch sandstone core plugs and Arabian light crude oil. The first formulation—the xanthan gum with 3% NaCl solution—recovered 14% of the residual oil from the core. In contrast, the modified xanthan gum with 3% NaCl solution recovered about 19% of the residual oil, which was 5% higher than the original xanthan gum. The xanthan gum acrylate is therefore more effective at boosting tertiary oil recovery in the sandstone core.

scholarly journals Depositional facies model and reservoir characterization of USANI field 1, Niger delta basin, Nigeria

2017 ◽  
Vol 5 (2) ◽  
pp. 57 ◽  
Author(s):  
Godwin Aigbadon ◽  
A.U Okoro ◽  
Chuku Una ◽  
Ocheli Azuka
Keyword(s):  
Tidal Flat ◽  
Water Saturation ◽  
Well Logs ◽  
Physical Analysis ◽  
Well Log ◽  
Delta Front ◽  
Depositional Facies ◽  
Facies Model ◽  
Core Data ◽  
The Core

The 3-D depositional environment was built using seismic data. The depositional facies was used to locate channels with highly theif zones and distribution of various sedimentary facies. The integration core data and the gamma ray log trend from the wells within the studied interval with right boxcar/right bow-shape indicate muddy tidal flat to mixed tidal flat environments. The bell–shaped from the well logs with the core data indicate delta front with mouth bar, the blocky box- car trend from the well logs with the core data indicate tidal point bar with tidal channel fill. The integration of seismic to well log tie display a good tie in the wells across the field. The attribute map from velocity analysis revealed the presence of hydrocarbons in the identified sands (A, B, C, D1, D2, D4, D5). The major faults F1, F2, F3 and F4 with good sealing capacity are responsible for hydrocarbon accumulation in the field. Detailed petro physical analysis of well log data showed that the studied interval are characterized by sand-shale inter-beds. Eight reservoirs were mapped at depth intervals of 2886m to 3533m with their thicknesses ranging from 12m to 407m. Also the Analysis of the petrophysical results showed that porosity of the reservoirs range from 14% to 28 %; permeability range from 245.70 md to 454.7md; water saturation values from 21.65% to 54.50% and hydrocarbon saturation values from 45.50% to 78.50 %. The by-passed hydrocarbons were identified and estimated in low resistivity pay sands D1, D2 at depth of 2884m – 2940m, sand D5 at depth of 3114m – 3126m respectively. The model serve as a basis for establishing facies model in the field.

scholarly journals Application of Implicit Pressure-Explicit Saturation Method to Predict Filtrated Mud Saturation Impact on the Hydrocarbon Reservoirs Formation Damage

Mathematics ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 1057 ◽  
Author(s):  
Mingxuan Zhu ◽  
Li Yu ◽  
Xiong Zhang ◽  
Afshin Davarpanah
Keyword(s):  
Porous Media ◽  
Water Saturation ◽  
Drilling Fluid ◽  
Formation Damage ◽  
Drilling Mud ◽  
Oil Viscosity ◽  
The Core ◽  
Oil Flow ◽  
Lower Porosity ◽  
Saturation Method

Hydrocarbon reservoirs’ formation damage is one of the essential issues in petroleum industries that is caused by drilling and production operations and completion procedures. Ineffective implementation of drilling fluid during the drilling operations led to large volumes of filtrated mud penetrating into the reservoir formation. Therefore, pore throats and spaces would be filled, and hydrocarbon mobilization reduced due to the porosity and permeability reduction. In this paper, a developed model was proposed to predict the filtrated mud saturation impact on the formation damage. First, the physics of the fluids were examined, and the governing equations were defined by the combination of general mass transfer equations. The drilling mud penetration in the core on the one direction and the removal of oil from the core, in the other direction, requires the simultaneous dissolution of water and oil flow. As both fluids enter and exit from the same core, it is necessary to derive the equations of drilling mud and oil flow in a one-dimensional process. Finally, due to the complexity of mass balance and fluid flow equations in porous media, the implicit pressure-explicit saturation method was used to solve the equations simultaneously. Four crucial parameters of oil viscosity, water saturation, permeability, and porosity were sensitivity-analyzed in this model to predict the filtrated mud saturation. According to the results of the sensitivity analysis for the crucial parameters, at a lower porosity (porosity = 0.2), permeability (permeability = 2 mD), and water saturation (saturation = 0.1), the filtrated mud saturation had decreased. This resulted in the lower capillary forces, which were induced to penetrate the drilling fluid to the formation. Therefore, formation damage reduced at lower porosity, permeability and water saturation. Furthermore, at higher oil viscosities, due to the increased mobilization of oil through the porous media, filtrated mud saturation penetration through the core length would be increased slightly. Consequently, at the oil viscosity of 3 cP, the decrease rate of filtrated mud saturation is slower than other oil viscosities which indicated increased invasion of filtrated mud into the formation.

FORMATION EVALUATION BY INSPECTION WITH THE BOREHOLE TELEVIEWER

Geophysics ◽  
1970 ◽  
Vol 35 (2) ◽  
pp. 254-269 ◽  
Author(s):  
Joe Zemanek ◽  
E. E. Glenn ◽  
L. J. Norton ◽  
R. L. Caldwell
Keyword(s):  
Well Log ◽  
Well Bore ◽  
Natural Fractures ◽  
Drilling Mud ◽  
Regional Tectonic ◽  
Oil Water ◽  
Orientation Information ◽  
Induced Fractures ◽  
Borehole Televiewer ◽  
Magnetic North

The televiewer takes an oriented acoustic picture of the inside of the well bore in the form of a continuous well log. The resulting log is a representation of the well bore wall as if it were split vertically along magnetic north and laid out flat. Both induced and natural fractures are defined in remarkable detail. Well bores can be filled with any homogeneous liquid such as lease crude oil, water, or drilling mud. Resolution of the tool is sufficient to locate fractures 1/32 inch wide. Examples of natural fractures in extremely fractured formations, in shales, and also drilling‐induced fractures are discussed. Fracture orientation information useful for local and regional tectonic studies is presented.

The Toll Free Expressway Policy for Part of Vehicles on Major Holidays Choice of Compensation Basis

2013 ◽  
Vol 409-410 ◽  
pp. 1325-1329
Author(s):  
Shu Li Shen ◽  
Guo Jie Zhao
Keyword(s):  
Listed Companies ◽  
Annual Reports ◽  
Proper Solution ◽  
Compensation Mechanism ◽  
The Core ◽  
Dea Models ◽  
Core Issue ◽  
Low Efficiency ◽  
Corporate Social ◽  
First Time

In 2012, for the first time China implemented the toll free expressway policy for part of vehicles on major holidays. However, there is no universal compensation mechanism thereafter. How to choose the compensation basis is the core issue of establishing such a mechanism. A proper solution is to choose suitable data of listed expressway companies as the basis. Factors including corporate social responsibility and compensation theory being taken into account, listed companies with an over 95% ratio of toll operations are sifted out, and part of companies with low efficiency are wiped out by DEA Models. 5 listed companies stand out from data sieving on Annual Reports 2012. Data can serve as the compensation basis of the year.

Relative Translucency of IPS E.max LT Core Materials after Veneering and Glazing

2011 ◽  
Vol 492 ◽  
pp. 358-361 ◽  
Author(s):  
Ting Sun ◽  
Long Quan Shao ◽  
Jun Ai ◽  
Bin Deng ◽  
Ning Wen
Keyword(s):  
Contrast Ratio ◽  
White Background ◽  
Ceramic System ◽  
The Core ◽  
Significant Difference ◽  
All Ceramic ◽  
Before And After ◽  
Different Thickness ◽  
Core Materials

This study compared the translucency of IPS e.max all-ceramic system of A and D color series veneered and glazed at clinically appropriate thicknesses. Core specimens (n = 5) of IPS e.max were produced and veneered with IPS e.max veneering porcelain to final dimensions (13 mm in diameter, 0.6 mm in thickness for core specimens with a thickness of 0.3 and 1.0 mm for core specimens with a thickness of 0.5 mm). Luminous reflectance was measured three times each specimen with a calibrated spectrophotometer after veneering and again after glazing cycle. Contrast ratios (CR=Yb/Yw) were measured from the luminous reflectance (Y)of the tested specimens with a black (Yb) and a white background (Yw). There was no significant difference in contrast ratios of specimens within the same color series before and after glazing (P > 0.05). Significant difference was found in the contrast ratios of specimens of the same color but different thickness before and after glazing (P < 0.05). The specimens with a thickness of 1.0mm presents significantly higher contrast ratios than specimens of the same color with a thickness of 0.6mm before and after glazing. The contrast ratios of glazed specimens were significantly lower than nonglazed ones. The Contrast ratio increases as the thickness of the core veneer materials increase, while luminosity and chroma are not related to relative translucency. The glazing cycle results in decreased opacity for core veneer materials.

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