Numerical modeling of self-potential in heterogeneous reservoirs

Geophysics ◽  
2022 ◽  
pp. 1-79
Author(s):  
Mutlaq Alarouj ◽  
Matthew David Jackson
Keyword(s):  
Numerical Modeling ◽  
Water Movement ◽  
New Technology ◽  
Water Injection ◽  
Heterogeneous Reservoirs ◽  
Reservoir Models ◽  
Water Breakthrough ◽  
Production Wells ◽  
Downhole Measurements ◽  
Self Potential

Monitoring water movement toward production wells through downhole measurements of self-potential (SP) was a promising new technology. However, there were uncertainties about its applicability in heterogeneous, multilayered reservoirs. Using numerical modeling, we investigated the likely magnitude and behavior of SP during oil production supported by water injection in two different models of such reservoirs. We found that the magnitude of the SP signal that would be measured along a production well increased as water approached the well, exceeding an assumed noise level of 0.1 mV before water breakthrough. We also found that, in the reservoir models tested, the maximum value of SP at the well skewed toward the fastest waterfront before water breakthrough. The trend of SP increasing at the well with time, together with the shape of the SP profile, were the prime indicators used to investigate water movement. In the reservoir models tested, before water breakthrough the fastest approaching waterfront could be detected approximately 20 m away from the well. However, subsequent waterfronts approaching the well in other layers could not be detected before breakthrough. The effect of these later waterfronts on the SP profile at the well was only detectable at breakthrough. We attributed this to the fact that the SP generated in these layers is masked by the high SP created by the fastest waterfront. Our findings emphasized the importance of an enhanced understanding of reservoir geology and rock electrical properties for better prediction and interpretation of SP.

Downhole Heating Technology – New Solution for Paraffinic Wells

2021 ◽  
Author(s):  
Mihaela Vlaicu ◽  
Vasile Marius Nae ◽  
Patrick Christian Buerssner ◽  
Stefan Liviu Firu ◽  
Natalya Logashova
Keyword(s):  
Technology Implementation ◽  
Online Monitoring ◽  
New Technology ◽  
Internal Diameter ◽  
Technology Application ◽  
Production Wells ◽  
The Difference ◽  
Wax Crystallization ◽  
Heating Technology ◽  
Production Losses

Abstract Paraffin represents one of the main case of failures and production losses which facing the entire oil industry. Prevention of paraffin deposition on the subsurface/surface equipment can be achieved by keeping the paraffin dissolved in crude oil or minimizing the adhesion or aggregation process of wax crystals. The paraffin problems which occur, conduct to gradual reduction of the tubular and pipelines internal diameter, restriction or valves blockages, and reduce the equipment capacity until the production is stop. Problems due to paraffin deposition varies and is different according with each commercial field, sometime the difference is from a well to well which producing from the same reservoir with different consistency. How we shall proceed? Before or after paraffin is field on the equipment? How could be avoid the future paraffin deposition? How long the selected method is proper for well ? The decision represents a combination based on oil's chemical & physical characteristics, well's behavior, method selected for prevention or elimination and combined with economic analysis and field experience. The paraffin inhibition applying is a common practice in OMV Petrom, which cover majority of the production wells. For the special wells, which the paraffin inhibition didn't provided satisfying results (multiple intervention due to paraffin deposition) was selected the Down Hole Heating technology (DHH) which was successfully tested in our company since 2014 thanks according with the yearly New Technology Program. The operating principle consists in heating the fluid volume from tubing using the heating cable which can be installed inside tubing, for NF and ESP wells or outside tubing for SRP or PCP wells. The cable is designed and located at the interval of wax crystallization appearance and heats the fluid to the temperature higher than the wax crystallization point (WAT). Since then, the DHH technology had an upward course, proven by high run life (highest value 2500 days / average 813 days) of the technology at the total 47 wells equipped, until this moment. Based on the successful results, recorded of 64% of old production wells equipped, it was decided to apply the technology at first completion of the new wells (36%), thus ensuring the protection of the new equipment. The paper offers an overview of DHH technology implementation, achievements, benefits and online monitoring of technology implementation starting with 2014 until today. The total impact shown a decreasing of no.of failures with 73,8%, the cost of intervention with 76,5%. The production losses decreased only with 5%, which certifies the fact that the technology helping production maintaining during the exploitation in comparison with production losses due paraffin issues recorded at wells without equipped with DHH technology. During 6 years of down hole heating technology application were developed candidate selection decision tree, monitoring the electrical efficiency, using the adaptability capacity of the technology from one well to another and integrate the temperature parameters in online monitoring system as part of digitalization concept of OMV Petrom, aspects which will be present in this article.

Development of efficiency increase methods for water injection

2020 ◽  
pp. 57-60
Author(s):  
K.I. Mustafaev ◽  
◽  
◽  
Keyword(s):  
Water Injection ◽  
Cost Effective ◽  
Current Interest ◽  
Residual Oil ◽  
Production Well ◽  
Field Development ◽  
Oil Reserves ◽  
Production Wells ◽  
Efficiency Increase

The production of residual oil reserves in the fields being in a long-term exploitation is of current interest. The extraction of residual oil in such fields was cost-effective and simple technological process and is always hot topic for researchers. Oil wells become flooded in the course of time. The appearance of water shows in production wells in the field development and operation is basically negative occurrence and requires severe control. Namely for this reason, the studies were oriented, foremost, to the prevention of water shows in production well and the elimination of its complications as well. The paper discusses the ways of reflux efficiency increase during long-term exploitation and at the final stages of development to prevent the irrigation and water use in production wells.

Identification of Micro Fractures in Cretaceous Bioclastic Limestone in Iraq and Its Influence on Development of Reservoirs

2021 ◽  
Author(s):  
Genjiu Wang ◽  
Dandan Hu ◽  
Qianyao Li
Keyword(s):  
Water Movement ◽  
Rock Fracture ◽  
Water Injection ◽  
Three Dimensional ◽  
Carbonate Reservoir ◽  
Distribution Data ◽  
Fracture Development ◽  
Reservoir Conditions ◽  
Data Volume ◽  
Southern Iraq

Abstract It is generally believed that Cretaceous bioclastic limestone in Mesopotamia basin in central and southern Iraq is a typical porous reservoir with weak fracture development. Therefore, previous studies on the fracture of this kind of reservoir are rare. As a common seepage channel in carbonate rock, fracture has an important influence on single well productivity and waterflooding development of carbonate reservoir. Based on seismic, core and production data, this study analyzes the development characteristics of fractures from various aspects, and discusses the influence of fractures on water injection development of reservoirs. Through special processing of seismic data, it is found that there are a lot of micro fractures in Cretaceous bioclastic limestone reservoir. Most of these micro fractures are filled fractures without conductivity under the original reservoir conditions. However, with the further development of the reservoir, the reservoir pressure, oil-water movement, water injection and other conditions have changed, resulting in the original reservoir conditions of micro fractures with conductivity. The water cut of many production wells in the high part of reservoir rises sharply. In order to describe the three-dimensional spatial distribution of fractures, the core data is used to verify the seismic fracture distribution data volume. After the verification effect is satisfied, the three-dimensional fracture data volume is transformed into the geological model to establish the permeability field including fracture characteristics. The results of numerical simulation show that water mainly flows into the reservoir through high angle micro fractures. Fractures are identified by seismic and fracture model is established to effectively recognize the influence of micro fractures on water injection development in reservoir development process, which provides important guidance for oilfield development of Cretaceous bioclastic limestone reservoir in the central and southern Iraq fields.

scholarly journals Studying of changes in the interaction of well during the water injection process

2019 ◽  
pp. 81-85
Author(s):  
Damir K. Sagitov
Keyword(s):  
Correlation Coefficient ◽  
Pair Correlation ◽  
Water Injection ◽  
Reservoir Pressure ◽  
Maintenance System ◽  
Displacement Front ◽  
Injection Process ◽  
Production Wells

The study of the causes of changes in the effectiveness of the reservoir pressure maintenance system in terms of the interaction of injection and production wells is an important and insufficiently studied problem, especially in terms of the causes of the attenuation of stable connections between the interacting wells. Based on the results of the calculation of the Spearman pair correlation coefficient, the reasons for the change in the interaction of wells during the flooding process at various stages were estimated. Of particular interest are identified four characteristic interactions, which are determined by the periods of formation of the displacement front.

scholarly journals Comparison Between Homogenous and Heterogeneous Reservoirs: A Parametric Study of Water Coning Phenomena

2021 ◽  
Vol 5 (1) ◽  
pp. 119-131
Author(s):  
Frzan F. Ali ◽  
Maha R. Hamoudi ◽  
Akram H. Abdul Wahab
Keyword(s):  
Production Rate ◽  
Oil Production ◽  
Water Production ◽  
Effective Parameters ◽  
Radial Cross Section ◽  
Heterogeneous Reservoirs ◽  
Water Breakthrough ◽  
Water Coning ◽  
Water Cut ◽  
Reservoir Simulator

Water coning is the biggest production problem mechanism in Middle East oil fields, especially in the Kurdistan Region of Iraq. When water production starts to increase, the costs of operations increase. Water production from the coning phenomena results in a reduction in recovery factor from the reservoir. Understanding the key factors impacting this problem can lead to the implementation of efficient methods to prevent and mitigate water coning. The rate of success of any method relies mainly on the ability to identify the mechanism causing the water coning. This is because several reservoir parameters can affect water coning in both homogenous and heterogeneous reservoirs. The objective of this research is to identify the parameters contributing to water coning in both homogenous and heterogeneous reservoirs. A simulation model was created to demonstrate water coning in a single- vertical well in a radial cross-section model in a commercial reservoir simulator. The sensitivity analysis was conducted on a variety of properties separately for both homogenous and heterogeneous reservoirs. The results were categorized by time to water breakthrough, oil production rate and water oil ratio. The results of the simulation work led to a number of conclusions. Firstly, production rate, perforation interval thickness and perforation depth are the most effective parameters on water coning. Secondly, time of water breakthrough is not an adequate indicator on the economic performance of the well, as the water cut is also important. Thirdly, natural fractures have significant contribution on water coning, which leads to less oil production at the end of production time when compared to a conventional reservoir with similar properties.

scholarly journals Application of the CL-systems technology for water injection wells at an oil and gas field

2021 ◽  
Vol 19 (3) ◽  
pp. 848-853
Author(s):  
Liliya Saychenko ◽  
Radharkrishnan Karantharath
Keyword(s):  
Oil And Gas ◽  
Water Injection ◽  
Oil And Gas Industry ◽  
Field Studies ◽  
High Water ◽  
Injection Wells ◽  
Gas Field ◽  
Water Breakthrough ◽  
Oil And Gas Field ◽  
High Water Cut

To date, the development of the oil and gas industry can be characterized by a decline in the efficiency of the development of hydrocarbon deposits. High water cut-off is often caused by water breaking through a highly permeable reservoir interval, which often leads to the shutdown of wells due to the unprofitability of their further operation. In this paper, the application of straightening the profile log technology for injection wells of the Muravlenkovsky oil and gas field is justified. In the course of this work, the results of field studies are systematized. The reasons for water breakthrough were determined, and the main ways of filtration of the injected water were identified using tracer surveys. The use of CL-systems technology based on polyacrylamide and chromium acetate is recommended. The forecast of the estimated additional oil produced was made.

Innovations of Gas Lift in Prolific, Long-perforations, and Multilayered Wells, Case Study in Sudan

2016 ◽  
Author(s):  
Xueqing Tang ◽  
Lirong Dou ◽  
Ruifeng Wang ◽  
Jie Wang ◽  
Shengbao Wang ◽  
...  
Keyword(s):  
High Water ◽  
Water Breakthrough ◽  
Start Up ◽  
Production Wells ◽  
Decline Curves ◽  
High Water Cut ◽  
Water Cut ◽  
Gas Lift

ABSTRACT Jake field, discovered in July, 2006, contains 10 oil-producing and 12 condensate gas-producing zones. The wells have high flow capacities, producing from long-perforation interval of 3,911 ft (from 4,531 to 8,442 ft). Production mechanisms include gas injection in downdip wells and traditional gas lift in updip, zonal production wells since the start-up of field in July, 2010. Following pressure depletion of oil and condensate-gas zones and water breakthrough, traditional gas-lift wells became inefficient and dead. Based on nodal analysis of entire pay zones, successful innovations in gas lift have been made since March, 2013. This paper highlights them in the following aspects: Extend end of tubing to the bottom of perforations for commingled production of oil and condensate gas zones, in order to utilize condensate gas producing from the lower zones for in-situ gas lift.Produce well stream from the casing annulus while injecting natural gas into the tubing.High-pressure nitrogen generated in-situ was used to kick off the dead wells, instead of installation of gas lift valves for unloading. After unloading process, the gas from compressors was injected down the tubing and back up the casing annulus.For previous high water-cut producers, prior to continuous gas lift, approximately 3.6 MMcf of nitrogen can be injected and soaked a couple of days for anti-water-coning.Two additional 10-in. flow lines were constructed to minimize the back pressure of surface facilities on wellhead. As a consequence, innovative gas-lift brought dead wells back on production, yielding average sustained liquid rate of 7,500 bbl/d per well. Also, the production decline curves flattened out than before.

Data-driven technique for analyzing the injector efficiency in a waterflooding operation

SIMULATION ◽  
2020 ◽  
Vol 96 (8) ◽  
pp. 701-710
Author(s):  
Ali Shabani ◽  
Mahdiyeh Sadat Moosavi ◽  
Davood Zivar ◽  
Hamid Reza Jahangiri
Keyword(s):  
Early Time ◽  
Oil Reservoirs ◽  
Data Driven ◽  
Production Data ◽  
Production Rates ◽  
Flow Paths ◽  
Water Breakthrough ◽  
Economical Evaluation ◽  
Production Wells ◽  
Underground Flow

Waterflooding is considered as one of the most common methods for improving the ultimate recovery of oil reservoirs. The efficiency of a waterflooding operation strongly depends on the determination and quantification of the relative connections between the injection and production wells. Injection and production rates are the most accessible data and they can provide useful information about the interwell connections. Recently, several data-driven approaches, such as the capacitance resistance model (CRM), have been presented based on available reservoir data. The CRM is a valuable analytical model for estimating the production rates and interwell connections through optimization of the production data. In this study, a CRM is used in order to estimate the production rate and evaluate the underground flow paths for both synthetic and real cases. A new concept called Value of Injection (VoI) is developed for the injectors to analyze their performance in the early time of the waterflooding prior to the significant water breakthrough. The calculated VoI is directly used for economical evaluation of the injectors. The results of this study show that a strong underground connection between an injector–producer pair does not always result in higher efficiency of the injector.

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