Low Resistivity Reservoir Pay Evaluation, New Opportunity for Further Development, Case Study On Gumai Formation Of B Field, Jambi Sub Basin, South Sumatera Basin

2021 ◽  
Keyword(s):  
Oil And Gas ◽  
Water Saturation ◽  
Neutron Density ◽  
Gas Field ◽  
Data Set ◽  
Volume Calculation ◽  
Low Resistivity ◽  
Shale Volume ◽  
Fluid Saturation ◽  
Further Development

The understanding of low resistivity reservoir zone is one of the most challenging cases for further development in order to optimize the remaining oil and gas field productions. In the Intra-Gumai Formation “B” Field where marine clastic reservoirs are deposited, a low resistivity reservoir is being developed as a new perforation and workover target. This study discusses how to identify the cause of low resistivity case and evaluate the proper petrophysical parameters to unlock the potential reservoir pay zones. The data set consists of petrographic, X-Ray Diffraction (XRD), Cation Exchange Capacity (CEC), routine core, Drill Stem Test ((DST) and wireline logs data. Petrographic, XRD, CEC and routine analysis were performed to recognize the low resistivity causes characterized by the presence of framework grain (quartz, K-feldspar and glaucony, calcite and kaolinite) observed in intergranular pore and also quartz overgrowth developed prior to kaolinite precipitation. Petrophysical analysis defines the reservoir property parameters by comparing some equations also validated with routine core and DST result. Based on the quantitative analysis carried out, namely the evaluation of the distribution of shale volume, calculation of porosity, and determination of water saturation, it is recommended to use the Stieber method for the distribution of shale volume in the reservoir and its properties, the neutron density porosity method to calculate porosity model, and the Waxman Smits method to determine the final fluid saturation model. Finally, by using the hydrocarbon saturation results in the current study, this interval was improved as pay zone. This method will be applied to other wells and other structures that have a similar depositional environment to increase hydrocarbon reserves in the same field.

scholarly journals WELL LOGS ANALYSIS TO ESTIMATE THE PARAMETERS OF SAWAN-2 AND SAWAN-3 GAS FIELD

2020 ◽  
Vol 5 (2) ◽  
pp. 69-75
Author(s):  
Raja Asim Zeb ◽  
Muhammad Haziq Khan ◽  
Intikhab Alam ◽  
Ahtisham Khalid ◽  
Muhammad Faisal Younas
Keyword(s):  
Physical Properties ◽  
Oil And Gas ◽  
Water Saturation ◽  
Total Porosity ◽  
Effective Porosity ◽  
Indus Basin ◽  
Log Analysis ◽  
Neutron Density ◽  
Gas Field ◽  
Lower Goru Formation

The lower Indus basin is leading hydrocarbon carriage sedimentary basin in Pakistan. Evaluation of two sorts out wells namely Sawan-2 and Sawan-3 has been assumed in this work for estimation and dispensation of petro physical framework using well log data. The systematic formation assessment by using petro physical studies and neutron density cross plots reveal that lithofacies mainly composed of sandstone. The hydrocarbon capability of the formation zone have been mark through several isometric maps such as water saturation, picket plots, cross plots, log analysis Phie vs depth and composite log analysis. The estimated petro physical properties shows that reservoir have volume of shale 6.1% and 14.0%, total porosity is observed between 14.6% and 18.2%, effective porosity ranges 12.5-16.5%, water saturation exhibits between 14.05% and 31.58%, hydrocarbon saturation ranges 68.42% -86.9%, The lithology of lower goru formation is dominated by very fine to fine and silty sandstone. The study method can be use within the vicinity of central Indus basin and similar basin elsewhere in the globe to quantify petro physical properties of oil and gas wells and comprehend the reservoir potential.

scholarly journals Simultaneous Seismic Inversion for Reservoir Characterization at Poseidon Field, Browse Basin, Australia

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Suleman Mauritz Sihotang ◽  
Ida Herawati
Keyword(s):  
Oil And Gas ◽  
Reservoir Characterization ◽  
Research Area ◽  
Seismic Inversion ◽  
Inversion Method ◽  
Well Log ◽  
Gas Field ◽  
Simultaneous Inversion ◽  
Fluid Saturation ◽  
Oil And Gas Field

Seismic inversion method has been widely used to obtain reservoir property in an oil and gas field. In this research, one of inversion methods known as simultaneous inversion is used to analyze reservoir characterization at Poseidon Field, Browse Basin. Simultaneous inversion is applied to partial angle stack data and result in volume of Acoustic Impedance (AI), Shear Impedance (SI) and Lame parameter (LMR). The objective of this study is to determine distribution of sandstone lithology with gas saturated in Plover reservoir formation. Sensitivity analysis is done by cross-plotting elastic and Lame parameter from five well log data and analyzing lithology type and fluid saturation. Based on those cross-plots, lithological type can be identified from AI, λρ, µρ and λ/µ parameters. Meanwhile, the presence of gas can be discriminated using SI, λρ, and λ/µ parameters. Gas-saturated sandstone presence is characterized by Lambda-Rho value less than 50 GPa g cc-1 and Lambda over Mu value less than 0.8 GPa g cc-1. Maps of each parameter are generated at reservoir interval. Based on those maps, it can be concluded that gas sand spread out in the eastern and western areas of research area.

Geological and Field Feasibility Study of Field Development Management Using Marker-Based Production Profiling Surveillance in Horizontal Wells: The Case Study of the Yuzhno-Vyintoiskoye Field

2021 ◽  
Author(s):  
Marat Rafailevich Dulkarnaev ◽  
Yuri Alexeyevich Kotenev ◽  
Shamil Khanifovich Sultanov ◽  
Alexander Viacheslavovich Chibisov ◽  
Daria Yurievna Chudinova ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Oil And Gas ◽  
Water Saturation ◽  
Clay Content ◽  
Horizontal Wells ◽  
Integrated Approach ◽  
Geological Structure ◽  
Gas Field ◽  
Field Development ◽  
Reservoir Rocks

In pursuit of efficient oil and gas field development, including hard-to-recover reserves, the key objective is to develop and provide the rationale for oil recovery improvement recommendations. This paper presents the results of the use of the workflow process for optimized field development at two field clusters of the Yuzhno-Vyintoiskoye field using geological and reservoir modelling and dynamic marker-based flow production surveillance in producing horizontal wells. The target reservoir of the Yuzhno-Vyntoiskoye deposit is represented by a series of wedge-shaped Neocomian sandstones. Sand bodies typically have a complex geological structure, lateral continuity and a complex distribution of reservoir rocks. Reservoir beds are characterised by low thickness and permeability. The pay zone of the section is a highly heterogeneous formation, which is manifested through vertical variability of the lithological type of reservoir rocks, lithological substitutions, and the high clay content of reservoirs. The target reservoir of the Yuzhno-Vyintoiskoye field is marked by an extensive water-oil zone with highly variable water saturation. According to paleogeographic data, the reservoir was formed in shallow marine settings. Sand deposits are represented by regressive cyclites that are typical for the progressing coastal shallow water (Dulkarnaev et al., 2020). Currently, the reservoir is in production increase cycle. That is why an integrated approach is used in this work to provide a further rationale and creation of the starting points of the reservoir pressure maintenance system impact at new drilling fields to improve oil recovery and secure sustainable oil production and the reserve development rate under high uncertainty.

Shallow Gas Identification using LWD Monopole Sonic: A-non Radioactive for Safe and Effective Logs Acquisition in Tunu Field, Mahakam Delta

2020 ◽  
Author(s):  
A.T. Santoso
Keyword(s):  
Oil And Gas ◽  
Neutron Density ◽  
Shallow Gas ◽  
Gas Field ◽  
Safety Issues ◽  
East Kalimantan ◽  
Main Challenge ◽  
Gas Identification ◽  
Fluid Interpretation ◽  
Mahakam Delta

The Tunu field is a swamp giant gas field located in the Mahakam Delta, East Kalimantan. Stratigraphically, this field has an anticline structure with three main intervals; Tunu Shallow Zone (TSZ), Fresh Water Zone (FWZ), and Tunu Main Zone (TMZ). Shallow gas reservoirs of TSZ have been produced since 2008, following the production of TMZ in the 1990s. Drilling targets in the shallow gas reservoir decreased significantly due to limited reservoir targets, high inclination wells and a low oil price environment. The utilization of radioactive source logging (density and neutron) on Logging While Drilling (LWD) tools is not recommended to be performed in open hole mode for operational and safety issues (e.g: tool stuck). Thus, LWD Monopole sonic is chosen as a replacement of LWD Neutron-Density logs and helps to differentiate between shallow gas potential and coal lithology which is the main challenge in TSZ at interval depth above 1200 mSS. The methodology utilized sonic semblance (STRA) and compressional slowness (DTc) data at real-time and memory data logs, so early decision can be made in drilling mode. In a gas-bearing reservoir, both semblance and slowness are missing, while in coal it produced strong semblance. In order to differentiate carbonate lithology, additional data, such as cutting, calcimetry, drilling Rate of Penetration and Gas While Drilling are utilized. During 2018-2020, 5 wells have been drilled using LWD Monopole sonic together with LWD GR-Resistivity-Neutron-Density (Triple Combo) to calibrate the fluid interpretation and 3 trial wells with only GR-Resistivity-Monopole Sonic. As a result, LWD Monopole sonic is able to differentiate between Gas and Coal based on semblance and slowness with a success ratio up to 80%. This LWD Monopole Sonic provides a non-radioactive solution for safe and effective logs acquisition for shallow gas identification that could be applied in oil and gas fields outside Mahakam.

Petrofacies classification using machine learning algorithms

Geophysics ◽  
2020 ◽  
Vol 85 (4) ◽  
pp. WA101-WA113 ◽  
Author(s):  
Adrielle A. Silva ◽  
Mônica W. Tavares ◽  
Abel Carrasquilla ◽  
Roseane Misságia ◽  
Marco Ceia
Keyword(s):  
Machine Learning ◽  
Oil And Gas ◽  
Water Saturation ◽  
Carbonate Reservoir ◽  
Machine Learning Algorithms ◽  
Carbonate Reservoirs ◽  
Training Data ◽  
Southeastern Brazil ◽  
Gradient Boosting ◽  
Data Set

Carbonate reservoirs represent a large portion of the world’s oil and gas reserves, exhibiting specific characteristics that pose complex challenges to the reservoirs’ characterization, production, and management. Therefore, the evaluation of the relationships between the key parameters, such as porosity, permeability, water saturation, and pore size distribution, is a complex task considering only well-log data, due to the geologic heterogeneity. Hence, the petrophysical parameters are the key to assess the original composition and postsedimentological aspects of the carbonate reservoirs. The concept of reservoir petrofacies was proposed as a tool for the characterization and prediction of the reservoir quality as it combines primary textural analysis with laboratory measurements of porosity, permeability, capillary pressure, photomicrograph descriptions, and other techniques, which contributes to understanding the postdiagenetic events. We have adopted a workflow to petrofacies classification of a carbonate reservoir from the Campos Basin in southeastern Brazil, using the following machine learning methods: decision tree, random forest, gradient boosting, K-nearest neighbors, and naïve Bayes. The data set comprised 1477 wireline data from two wells (A3 and A10) that had petrofacies classes already assigned based on core descriptions. It was divided into two subsets, one for training and one for testing the capability of the trained models to assign petrofacies. The supervised-learning models have used labeled training data to learn the relationships between the input measurements and the petrofacies to be assigned. Additionally, we have developed a comparison of the models’ performance using the testing set according to accuracy, precision, recall, and F1-score evaluation metrics. Our approach has proved to be a valuable ally in petrofacies classification, especially for analyzing a well-logging database with no prior petrophysical information.

scholarly journals Shale volume and porosity delineation of coast swamp depobelt in Niger delta region, Nigeria, using well log

2019 ◽  
Vol 7 (2) ◽  
pp. 142
Author(s):  
Ubong Essien
Keyword(s):  
Niger Delta ◽  
Gamma Ray ◽  
Water Saturation ◽  
Effective Porosity ◽  
Neutron Density ◽  
Well Log ◽  
Shale Formations ◽  
Log Data ◽  
Shale Volume ◽  
Niger Delta Region

Well log data from two wells were evaluated for shale volume, total and effective porosity. Well log data were obtained from gamma ray, neutron-density log, resistivity, sonic and caliper log respectively. This study aimed at evaluating the effect of shale volume, total and effective porosity form two well log data. The results of the analysis depict the presence of sand, sand-shale and shale formations. Hydrocarbon accumulation were found to be high in sand, fair in sand-shale and low in shale, since existence of shale reduces total and effective porosity and water saturation of the reservoir. The thickness of the reservoir ranged from 66 – 248.5ft. The average values of volume of shale, total and effective porosity values ranged from 0.004 – 0.299dec, 0.178 – 0.207dec and 0.154 – 0.194dec. Similarly, the water saturation and permeability ranged from 0.277 – 0.447dec and 36.637 - 7808.519md respectively. These values of total and effective porosity are high in sand, fair in sand-shale and low in shale formations. The results for this study demonstrate: accuracy, applicability of these approaches and enhance the proper evaluation of petrophysical parameters from well log data.    

scholarly journals Sandstone reservoir characteristics of Rio Del Rey basin, Cameroon, using well-logging analysis

2021 ◽  
Author(s):  
Janvier Domra Kana ◽  
Ahmad Diab Ahmad ◽  
Daniel Hervé Gouet ◽  
Xavier Djimhoudouel ◽  
Serge Parfait Koah Na Lebogo
Keyword(s):  
Oil And Gas ◽  
Gamma Ray ◽  
Water Saturation ◽  
Effective Porosity ◽  
High Resistivity ◽  
Neutron Density ◽  
Oil And Gas Exploration ◽  
Hydrocarbon Reservoir ◽  
Offshore Oil And Gas ◽  
Cloud Of Points

AbstractThe present work deals with an interpretation of well log data (gamma ray (GR), resistivity, density, and neutron) from four wells, namely P-1, P-2, P-3 and P-4 in the study area of the Rio Del Rey basin. The well logs analysis indicates five potential sandstone reservoirs at the P-1, two at the P-2, four at the P-3 and six at the P-4. The neutron–density-GR logs highlight the sandstone gas reservoir characterized by high resistivity and crossover between neutron density. The neutron–density-GR cross-plot confirms the presence of sandstone containing hydrocarbons by a displacement of the cloud of points, from low to medium GR values, from the sandstone line to the left. Petrophysical parameters exhibit the value 12–41% for a volume of shale, 15–34% for effective porosity, 29–278 mD for permeability and 3–63% for water saturation. The three potential hydrocarbon reservoir saturation ranges from 22 to 45%. The study will contribute to future offshore oil and gas exploration and development in the Rio Del Rey basin, based on the geological and geophysical characteristics of the reservoirs delineated.

scholarly journals Petrophysical Properties of Khasib Formation in East Baghdad Oil Field Southern Area

2020 ◽  
Vol 21 (4) ◽  
pp. 41-48
Author(s):  
Layth Abdulmalik Jameel ◽  
Fadhil S. Kadhim ◽  
Hussein Al-Sudani
Keyword(s):  
Water Saturation ◽  
High Water ◽  
Oil Field ◽  
Neutron Density ◽  
Well Log ◽  
Petrophysical Properties ◽  
Shale Volume ◽  
Southern Area ◽  
Volume Porosity ◽  
Well Log Analysis

Petrophysical properties evaluation from well log analysis has always been crucial for the identification and assessment of hydrocarbon bearing zones. East Baghdad field is located 10 km east of Baghdad city, where the southern area includes the two southern portions of the field, Khasib formation is the main reservoir of East Baghdad oil field. In this paper, well log data of nine wells have been environmentally corrected, where the corrected data used to determine lithology, shale volume, porosity, and water saturation. Lithology identified by two methods; neutron-density and M-N matrix plots, while the shale volume estimated by single shale indicator and dual shale indicator, The porosity is calculated from the three common porosity logs; density log, neutron log, and sonic log, the water saturation is calculated by Indonesian model and Archie equation, and the results of the two methods were compared with the available core data to check the validity of the calculation. The results show that the main lithology in the reservoir is limestone, shale volume ranged between 0.152 to 0.249, porosity between 0.147 to 0.220, and water saturation from 0.627 to 0.966, the high-water saturation indicate that the water quantity is the determining factor of the reservoir units.

scholarly journals ANALISIS PETROFISIKA DAN PENYEBAB LOW RESISTIVITY RESERVOIR ZONE BERDASARKAN DATA LOG, SEM, XRD DAN PETROGRAFI PADA LAPANGAN X SUMATERA SELATAN

2020 ◽  
Vol 4 (2) ◽  
pp. 31-46
Author(s):  
Rita Aprilia ◽  
Ordas Dewanto ◽  
Karyanto Karyanto ◽  
Aldis Ramadhan
Keyword(s):  
Oil And Gas ◽  
Water Saturation ◽  
Water Reservoir ◽  
Water Layer ◽  
Research Area ◽  
Low Resistivity ◽  
Hydrocarbon Reservoir ◽  
Gas Layer ◽  
Data Log ◽  
Resistivity Log

Hydrocarbon reservoir zone located on Low Resistivity is a typical and hidden oil and gas layer which always wrong in assessing as a water layer due to the complex geological origin and resistivity log limitation in identifying hydrocarbon. Presence of shale in a reservoir will decreasing resistivity value and increasing saturation value, so it can cause the results of the analysis to be pessimistic in the identification of hydrocarbons. In that case need to do analysis to core data on research area in order to know the cause of Low Resistivity on reservoir zone that having a probability of hydrocarbon content. Reservoir zone that has low resistivity value is at depth 1572-1577 mD. In this zone, it has a low resistivity value around 2.7- 4.4 ohm-m, with water saturation value around 47%-74% which causes on Low Resistivity reservoir zone to be between hydrocarbons and water reservoir zone. Then, on this research, Low Resistivity is also caused by Lamination Clay of shale type presence which consists of several types of Clay which can cause reservoir zone is at low resistivity value. This Clay type consist of Kaolite 20%, Illite 4%, and Chlorite 4% minerals as well as the presence of other minerals as proponent of low resistivity that is Quartz 60%, Plagioclase 9% and Calcite 3% as conductive minerals.

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