Marginal Field with Low Resistivity Pay Zone in Central Sumatra Basin: What We Can Learn

2020 ◽  
Author(s):  
A. Arief
Keyword(s):  
Oil Field ◽  
Oil Fields ◽  
High Resistivity ◽  
Core Analysis ◽  
3D Seismic ◽  
Unique Challenge ◽  
Low Resistivity ◽  
Central Sumatra ◽  
Marginal Field ◽  
Special Core Analysis

The XY field is a marginal oil field in the western part of the Central Sumatra Basin (CSB) and is covered by 3D seismic. The XY field started production in 2012. The oil originates from the Lower Sihapas sandstone reservoir, similar to other oil fields in the CSB. The Lower Sihapas sandstone as the primary reservoir in the XY field has overall gross thickness reaching up to 58 ft. Routine Core Analysis (RCAL) and Special Core Analysis (SCAL) are available from reservoir core interval in one of the wells. The reservoir consists of very fine to fine, well sorted sandstone, some pyrite, glauconitic and calcareous with thin layer of claystone and siltstone. The low and relatively high resistivity characteristics of the oil and water bearing zone respectively in the XY field becomes a unique challenge that partly causes an overestimation of the reserves. Prudent and detailed analyses for petrophysics and modeling in the XY field has been undertaken to re-evaluate and minimize errors. This paper will address some of the issues and causes related to low resistivity found in the main pay zone in the XY field as input for a strategic concept of finding and evaluating other exploration candidates surrounding the area.

scholarly journals High Resistivity Reservoirs (Causes And Effects): Sahara Field, Murzuq Basin, Libya

Warta Geologi ◽  
2020 ◽  
Vol 46 (3) ◽  
pp. 230-234
Author(s):  
Abubaker Alansari ◽  
◽  
Ahmed Salim ◽  
Abdul Hadi Abd Rahman ◽  
Nuri Fello ◽  
...  
Keyword(s):  
Capillary Pressure ◽  
Water Saturation ◽  
Oil Field ◽  
High Resistivity ◽  
Geological Time ◽  
Water Contact ◽  
Data Set ◽  
Low Resistivity ◽  
Resistant Medium ◽  
Oil Water

High and low resistivity values is an alarming phenomenon that is usually associated with a very complicated reservoir history and worth looking into. Ordovician sandstone reservoirs are the primary oil producers in the Murzuq basin oil fields that is characterized with an average porosity of 14%, permeability range 410-10,760 md and clean quartz aranite composition. More than fifty wells were drilled in Sahara oil field, but only four of them were announced to have high resistivity values more than 100k ohm-m and ten others to be considered as low resistivity wells (below 50 ohm-m). Therefore, average deep resistivity was mapped in both water and oil legs using all available data set, and the top reservoir was employed as a trend map. They showed distinctive trends for low resistivity readings in oil-leg and confirmed the extreme deep resistivity nature for the wells (W7, W8, W9, and W10). Height above oil water contact and capillary pressure was also calculated for all the wells and revealed a high pressure (400 psi) at the location of the high resistivity wells. As a result, of higher capillary pressure in thicker reservoir area oil might have been able to displace water through geological time by benefitting of more considerable height above oil-water contact, higher connate pressure, and buoyancy forces support, which resulted in occupying all the larger pores and pushed the water into minor scattered pores leading to gradual alteration of reservoir wettability from water to oil-wet. Hence, the brine fluids will no longer be connected to each other inside the pore system. Therefore, they will lose their contribution to resistivity readings, and the resistivity tool will encounter a more resistant medium, which in turn will lead to underestimation of water saturation.

Rekonstruksi dan Validasi Data Permeabilitas Relatif Untuk Proses History Matching Dalam Simulasi Reservoir Pengembangan Lapangan X

2015 ◽  
Vol 4 (2) ◽  
pp. 44-52
Author(s):  
Novia Rita ◽  
Tomi Erfando
Keyword(s):  
History Matching ◽  
Core Analysis ◽  
Black Oil ◽  
Special Core Analysis

Sebelum suatu model reservoir digunakan, terlebih dahulu dilakukan history matching atau menyesuaikan kondisi model dengan dengan kondisi reservoir. Salah satu parameter yang perlu disesuaikan adalah permeabilitas relatif. Untuk melakukan rekonstruksi nilai permeabilitas relatifnya dibutuhkan data SCAL (Special Core Analysis) dari sampel core. Langkah awal rekonstruksi adalah dengan melakukan normalisasi data permeabilitas relatif (kr) dan saturasi air (Sw) dari data SCAL yang berasal dari tiga sampel core. Setelah dilakukan nomalisasi, dilakukan denormalisasi data permeabilitas relatif yang akan dikelompokkan berdasarkan jenis batuannya. Setelah dilakukan history matching menggunakan black oil simulator, data denormalisasi tersebut belum sesuai dengan kondisi aktual. Selanjutnya digunakan persamaan Corey untuk rekonstruksi kurva permeabilitas relatifnya. Hasil dari persamaan tersebut didapat bahwa nilai kro dan krw jenis batuan 1 sebesar 0,25 dan 0,09 kemudian nilai kro dan krw untuk jenis batuan 2 sebesar 0,4 dan 0,2. Nilai permeabilitas dari persamaan Corey digunakan untuk melakukan history matching, hasilnya didapat kecocokan (matching) dengan keadaan aktual. Berdasarkan hasil simulasi, nilai produksi minyak aktualnya adalah 1.465.650 bbl sedangkan produksi dari simulasi adalah 1.499.000 bbl. Artinya persentase perbandingan aktual dan simulasinya adalah 1,14% yang dapat dikatakan cocok karena persentase perbedaannya di bawah 5%.

scholarly journals A new framework for selection of representative samples for special core analysis

2020 ◽  
Vol 5 (3) ◽  
pp. 210-226 ◽  
Author(s):  
Abouzar Mirzaei-Paiaman ◽  
Seyed Reza Asadolahpour ◽  
Hadi Saboorian-Jooybari ◽  
Zhangxin Chen ◽  
Mehdi Ostadhassan
Keyword(s):  
Core Analysis ◽  
Representative Samples ◽  
Special Core Analysis ◽  
New Framework ◽  
Selection Of

scholarly journals Studying the Depth Structure of the Kyrgyz Tien Shan by Using the Seismic Tomography and Magnetotelluric Sounding Methods

Geosciences ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 122
Author(s):  
Irina Medved ◽  
Elena Bataleva ◽  
Michael Buslov
Keyword(s):  
Seismic Tomography ◽  
High Velocity ◽  
Fault Zones ◽  
Magnetotelluric Sounding ◽  
Tien Shan ◽  
High Resistivity ◽  
Low Velocity ◽  
Low Resistivity ◽  
Velocity Models ◽  
Fluid Saturation

This paper presents new results of detailed seismic tomography (ST) on the deep structure beneath the Middle Tien Shan to a depth of 60 km. For a better understanding of the detected heterogeneities, the obtained velocity models were compared with the results of magnetotelluric sounding (MTS) along the Kekemeren and Naryn profiles, running parallel to the 74 and 76 meridians, respectively. We found that in the study region the velocity characteristics and geoelectric properties correlate with each other. The high-velocity high-resistivity anomalies correspond to the parts of the Tarim and Kazakhstan-Junggar plates submerged under the Tien Shan. We revealed that the structure of the Middle Tien Shan crust is conditioned by the presence of the Central Tien Shan microcontinent. It manifests itself as two anomalies lying one below the other: the lower low-velocity low-resistivity anomaly, and the upper high-velocity high-resistivity anomaly. The fault zones, limiting the Central Tien Shan microcontinent, appear as low-velocity low-resistivity anomalies. The obtained features indicate the fluid saturation of the fault zones. According to the revealed features of the Central Tien Shan geological structure, it is assumed that the lower-crustal low-velocity layer can play a significant role in the delamination of the mantle part of the submerged plates.

Integration of 3D Seismic and Reservoir Simulation for Remaining Oil Exploitation in a Heavy-Oil Field: A Case Study

2010 ◽  
Author(s):  
Yun Ling ◽  
Xuri Huang ◽  
Xiangyu Guo ◽  
Yingtao Cai
Keyword(s):  
Reservoir Simulation ◽  
Heavy Oil ◽  
Oil Field ◽  
3D Seismic ◽  
Oil Exploitation ◽  
Remaining Oil

Flow Assurance in Buzios Field: Key Challenges and Implemented Solutions

2021 ◽  
Author(s):  
Ivan Noville ◽  
Milena da Silva Maciel ◽  
Anna Luiza de Moraes y blanco de Mattos ◽  
João Gabriel Carvalho de Siqueira
Keyword(s):  
Liquid Flow Rate ◽  
Hydrate Formation ◽  
Oil Field ◽  
Oil Fields ◽  
Injection System ◽  
Flow Assurance ◽  
Water Alternating Gas ◽  
Early Design Stages ◽  
Scale Deposition ◽  
Full Operation

Abstract This article's goal is to present some of the main flow assurance challenges faced by PETROBRAS in the Buzios oil field, from its early design stages to full operation, up to this day. These challenges include: hydrate formation in WAG (Water Alternating Gas) operations; reliability of the chemical injection system to prevent scale deposition; increasing GLR (Gas Liquid Ratio) management and operations with extremely high flowrates. Flow assurance experience amassed in Buzios and in other pre-salt oil fields, regarding all these presented issues, is particularly relevant for the development of future projects with similar characteristics, such as high liquid flow rate, high CO2 content and high scaling potential.

Numerical Simulation of Gas Lift Optimization Using Artificial Intelligence for a Middle Eastern Oil Field

2021 ◽  
Author(s):  
Mohammed Ahmed Al-Janabi ◽  
Omar F. Al-Fatlawi ◽  
Dhifaf J. Sadiq ◽  
Haider Abdulmuhsin Mahmood ◽  
Mustafa Alaulddin Al-Juboori
Keyword(s):  
Genetic Algorithm ◽  
Sensitivity Analysis ◽  
Middle Eastern ◽  
Optimization Technique ◽  
Injection Rate ◽  
Oil Field ◽  
Oil Fields ◽  
Reservoir Pressure ◽  
Artificial Lift ◽  
Gas Lift

Abstract Artificial lift techniques are a highly effective solution to aid the deterioration of the production especially for mature oil fields, gas lift is one of the oldest and most applied artificial lift methods especially for large oil fields, the gas that is required for injection is quite scarce and expensive resource, optimally allocating the injection rate in each well is a high importance task and not easily applicable. Conventional methods faced some major problems in solving this problem in a network with large number of wells, multi-constrains, multi-objectives, and limited amount of gas. This paper focuses on utilizing the Genetic Algorithm (GA) as a gas lift optimization algorithm to tackle the challenging task of optimally allocating the gas lift injection rate through numerical modeling and simulation studies to maximize the oil production of a Middle Eastern oil field with 20 production wells with limited amount of gas to be injected. The key objective of this study is to assess the performance of the wells of the field after applying gas lift as an artificial lift method and applying the genetic algorithm as an optimization algorithm while comparing the results of the network to the case of artificially lifted wells by utilizing ESP pumps to the network and to have a more accurate view on the practicability of applying the gas lift optimization technique. The comparison is based on different measures and sensitivity studies, reservoir pressure, and water cut sensitivity analysis are applied to allow the assessment of the performance of the wells in the network throughout the life of the field. To have a full and insight view an economic study and comparison was applied in this study to estimate the benefits of applying the gas lift method and the GA optimization technique while comparing the results to the case of the ESP pumps and the case of naturally flowing wells. The gas lift technique proved to have the ability to enhance the production of the oil field and the optimization process showed quite an enhancement in the task of maximizing the oil production rate while using the same amount of gas to be injected in the each well, the sensitivity analysis showed that the gas lift method is comparable to the other artificial lift method and it have an upper hand in handling the reservoir pressure reduction, and economically CAPEX of the gas lift were calculated to be able to assess the time to reach a profitable income by comparing the results of OPEX of gas lift the technique showed a profitable income higher than the cases of naturally flowing wells and the ESP pumps lifted wells. Additionally, the paper illustrated the genetic algorithm (GA) optimization model in a way that allowed it to be followed as a guide for the task of optimizing the gas injection rate for a network with a large number of wells and limited amount of gas to be injected.

scholarly journals The use of the method of controlling the electrochemical parameters of aqueous solutions to combat complications in the operation of oil field pipelines

2021 ◽  
Vol 225 ◽  
pp. 01008
Author(s):  
Oleg Latypov ◽  
Sergey Cherepashkin ◽  
Dina Latypova
Keyword(s):  
Aqueous Solutions ◽  
Oil And Gas ◽  
High Efficiency ◽  
Oil Field ◽  
Oil Fields ◽  
Control Methods ◽  
Test Results ◽  
Chemical Reagents ◽  
Electrochemical Parameters ◽  
Very High

Corrosion of equipment in the oil and gas complex is a global problem, as it contributes to huge material costs and global disasters that violate the environment. Corrosion control methods used to protect equipment do not always ensure the absolute safety of the operation of oil and gas facilities. Moreover, they are quite expensive. The developed method for controlling the electrochemical parameters of aqueous solutions to combat complications during the operation of oil-field pipelines provides the necessary protection against corrosion. The method is economical and environmentally friendly, since it does not require the use of chemical reagents. The test results have shown a very high efficiency in dealing with complications in oil fields.

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