scholarly journals New Reservoir Grading Method for Tight Gas Reservoir – One Case Study in Kekeya Block, Tuha Basin, China

2015 ◽  
Vol 8 (1) ◽  
pp. 167-171
Author(s):  
Fangfang Wu ◽  
Jinchuan Zhang ◽  
Liuzhong Li ◽  
Jinlong Wu
Keyword(s):  
Flow Unit ◽  
Reservoir Evaluation ◽  
Flow Units ◽  
Core Dataset ◽  
Tight Gas Reservoir ◽  
Set Up ◽  
Productivity Prediction ◽  
Hydraulic Flow Units ◽  
New Reservoir

Tight sand reservoir is usually characterized by high heterogeneity and complex pore structure, which makes the permeability calculation a big challenge and leads to difficulties in reservoir classification and productivity evaluation. First, five different Hydraulic Flow Units and respective Porosity-permeability relations were built based on core dataset from Kekeya block, Tuha Basin; and then with BP Neutron Network method, flow unit was classified for un-cored intervals using normalized logging data, and permeability was calculated accordingly. This improved the accuracy of permeability calculation and helped a lot on un-cored reservoir evaluation. In addition, based on porosity, permeability and flow unit type, a new reservoir grading chart was set up by incorporating the testing or production data, which provides important guidance for productivity prediction and reservoir development.

Integrating XRD and Well Logging Data to Establish Electro-Facies and Permeability Models for an Unconventional Heterogeneous Tight Gas Reservoir, Obaiyed Giant Gas Field

2021 ◽  
Author(s):  
Ibrahim Mabrouk
Keyword(s):  
Development Strategy ◽  
Flow Unit ◽  
Petrographic Analysis ◽  
Production Forecast ◽  
Gas Field ◽  
Hydraulic Flow ◽  
Heterogeneous Reservoirs ◽  
Flow Units ◽  
Tight Gas Reservoir ◽  
Hydraulic Flow Units

Abstract Formation evaluation in heterogeneous reservoirs can be very challenging especially in fields that extend over several kilometers in area where the permeability varies from 0.1 mD up to 1000 D within the same porosity. The porosity, hydrocarbon saturation and net sand thickness in most of Obaiyed field wells are consistent; hence, the productivity of these wells is enormously dependent on the reservoir permeability. Since the permeability is highly heterogeneous, initial production rate of the wells varies between few MMSCFD to almost one hundred MMSCFD. The huge permeability variation led to a tremendous uncertainty in the dynamic modeling, which resulted in an inaccurate production forecast affecting the field economics estimation. Understanding permeability distribution and heterogeneity in Obaiyed field is the key factor for establishing a realistic permeability model, which will lead to a successful field development strategy. Extensive work was performed to understand key factors that govern the permeability in Obaiyed using the data of 1-kilometer length of cores acquired in more than 50 wells covering different reservoir properties in the field. Core data were used to separate the reservoir into different Hydraulic Flow Units (HFU) according to Amaefule's work performed on the Kozeny-Carmen model. Afterwards, a correlation between the HFU and well logs was established using IPSOM Electro-Facies module in order to define the flow units in un-cored wells. The result of this correlation was used to calibrate a Porosity-Permeability relationship for each flow unit. The next step was examining the clay-type distribution and diagenesis in each flow unit using the petrographic analysis (XRD) results from the core xdata. All factors controlling the permeability can now be represented in hydraulic flow units which are considered as a method of measurement of the reservoir quality. Consequently, property maps were constructed showing the location and continuity of each of the flow units, leading to a more deterministic approach in the well placement process. Based on this new work methodology, a production cut-off criteria relating the reservoir productivity to both clay minerals presence and percentages was established for multiple wells scenarios. As a result, the development strategy of the field changed from only vertical wells to include horizontal wells as well which proved to be the only economic approach to produce the Illite dominated zones. This paper presents a workflow to provide a representative estimation of permeability in extremely heterogeneous reservoirs especially the ones dominated by complex clay distribution.

scholarly journals Hydraulic flow unit classification from core data: case study of the Z gas reservoir, Poland

2021 ◽  
Vol 62 (3) ◽  
pp. 29-36
Author(s):  
Keyword(s):  
Flow Unit ◽  
Reservoir Rock ◽  
Hydrocarbon Production ◽  
Reservoir Rocks ◽  
Hydraulic Flow ◽  
Flow Units ◽  
Porosity And Permeability ◽  
Homogeneous Section ◽  
Hydraulic Flow Units

Permeability and porosity are essential parameters for estimating hydrocarbon production from reservoir rocks. They are combined in an additional factor, the Flow Zone Index (FZI), which is the basis for defining the hydraulic flow unit (HFU). Each HFU is a homogeneous section of a reservoir rock with stable parameters that allow for media flow. Hydraulic flow units are determined from the porosity and permeability of core or well logs. The simple statistical methods are applied for HFU classification and then improve permeability prediction. This paper also shows how to quickly apply the global hydraulic elements (GHE) method for HFU classification. The methodology is tested on the Miocene formation of a deltaic facies from the Carpathian Foredeep in South-Eastern Poland.

scholarly journals Application of Seismic Attribute Technique to estimate the 3D model of Hydraulic Flow Units: A case study of a gas field in Iran

2018 ◽  
Vol 27 (2) ◽  
pp. 145-157 ◽  
Author(s):  
Mohamad Iravani ◽  
Mahdi Rastegarnia ◽  
Dariush Javani ◽  
Ali Sanati ◽  
Seyed Hasan Hajiabadi
Keyword(s):  
3D Model ◽  
Seismic Attribute ◽  
Gas Field ◽  
Hydraulic Flow ◽  
Flow Units ◽  
Hydraulic Flow Units

scholarly journals Investigation of Hydrokinetic Properties of Hydrogeologic Units of Sandy Lithofacies: A Case Study of Parts of Enugu State, Southeastern Nigeria

2020 ◽  
Author(s):  
Johnson Cletus Ibuot ◽  
Emmanuel T. Omeje ◽  
Daniel Nnemeka Obiora
Keyword(s):  
Mean Value ◽  
Northwestern Part ◽  
Southeastern Nigeria ◽  
Contour Maps ◽  
Flow Units ◽  
Electrical Sounding ◽  
Enugu State ◽  
Hydraulic Flow Units ◽  
Very High

Abstract Vertical electrical sounding employing schlumberger electrode configuration was carried out in thirty locations across some parts of Enugu state, to investigate the hydrokinetic properties of hydrogeologic units of the study area. The result shows that resistivity and thickness of aquifer ranges from 27.3 to 59569.0 Ωm and 23.3 to 242.1 m respectively. Permeability and fractional porosity values range from 4531.254 to 74006.76 mD and 0.026 to 0.159. AQI having a mean value of 13.5451 µm range from 6.809 to 52.976 µm. FZI and HFU values range from 37.582 to 1962.074 µm and 18 to 26 respectively. Contour maps were generated from the results to visualize the variations of the hydrokinetic properties across the study area. From the contour maps, southern part of the study area was identified to be characterized with high AQI, FZI and HFU with northwestern part and a small proportion along the southwestern part identified as areas with low AQI, FZI and HFU. HFU along the study area was observed to be fractionated into nine distinct properties (HFU 18, HFU 19, HFU 20, HFU 21, HFU 22, HFU 23, HFU 24, HFU 25, and HFU 26) with HFU 19 and HFU 20 dominating the area. The results from the nine hydraulic flow units based on flow zone indicator cut off values (Log FZI ˃ 0.25) shows that the reservoir quality is very high.

scholarly journals Rock typing based on hydraulic and electric flow units for reservoir characterization of Nubia Sandstone, southwest Sinai, Egypt

2021 ◽  
Author(s):  
Abdel Moktader A. El-Sayed ◽  
Nahla A. El Sayed ◽  
Hadeer A. Ali ◽  
Mohamed A. Kassab ◽  
Salah M. Abdel-Wahab ◽  
...  
Keyword(s):  
Iron Oxides ◽  
Reservoir Characterization ◽  
Flow Unit ◽  
Reservoir Quality ◽  
Thin Sections ◽  
Hydraulic Flow ◽  
Rock Types ◽  
Flow Units ◽  
Reservoir Quality Index ◽  
Hydraulic Flow Units

AbstractThe present work describes and evaluates the reservoir quality of the sandstone of the Nubia Formation at the Gebel Abu Hasswa outcrop in southwest Sinai, Egypt. Hydraulic flow unit (HFU) and electrical flow unit (EFU) concepts are implied to achieve this purpose. The Paleozoic section made up of four formations has been studied. The oldest is Araba Formation followed by Naqus formations (Nubia C and D) overlay by Abu Durba, Ahemir and Qiseib formations (Nubia B), where the Lower Cretaceous (Nubia A) is represented by the Malha Formation. The studied samples have been collected from Araba, Abu Durba, Ahemir and the Malha formations. The hydraulic flow unit (HFU) discrimination was carried out based on permeability and porosity relationship, whereas the electrical flow unit (EFU) differentiation was carried out based on the relationship between formation resistivity factor and porosity. Petrographic investigation of the studied thin sections illustrates that the studied samples are mainly quartz arenite. Important roles to enhance or reduce the pore size and/or pore throats controlling the reservoir petrophysical behavior are due to the diagenetic processes. The present study used the reservoir quality index (RQI) and Winland R35 as additional parameters applied to discriminate the HFUs. The study samples have five hydraulic flow units of different rock types, where the detected electrical flow units are only three. The differences between them are may be due to the cementation process with iron oxides that might act as pore filling, lining and pore bridging, sometimes bridges helping to decrease permeability without serious reduction in porosity. The reduction between the number of EFUs and HFUs comes from the effect of diagenesis processes which is responsible for a precipitation of different cement types such as different clay minerals and iron oxides.

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