Pulling the Production: A New Way of Looking into Brown Field Reservoirs

2021 ◽  
Author(s):  
A.. Ghosh ◽  
J.. Zacharia ◽  
V.. Kumar ◽  
R.. S. Chauhan ◽  
R.. Santhosh Kumar ◽  
...  
Keyword(s):  
Promising Result ◽  
Water Injection ◽  
Qualitative Evaluation ◽  
Oil Production ◽  
Integrated Approach ◽  
Carbonate Reservoir ◽  
Added Value ◽  
High Permeability ◽  
Horizontal Drain ◽  
Water Cut

Abstract One of the major brownfields in offshore India was producing for three decades from main carbonate reservoirs of the Eocene and Oligocene age. Average production of this brownfield is approximately 11,000 barrels of oil per day (BOPD). To maintain the declining reservoir pressure, the field has been under active water injection for more than two decades. However, being a complex carbonate reservoir with high textural heterogeneity, the water-front movement is not very well understood and monitored. To increase the oil production, the operator started drilling horizontal drain-holes from the platforms and has adopted a conventional perforated and blind tubing combination as a completion strategy. However, it was found that wells were performing poorly with very high water cut. An integrated and comprehensive petrophysical workflow was applied that used data analysis and the added value of advanced 3D acoustic data in combination with nuclear magnetic resonance (NMR) data to provide a rapid realistic solution to avoid such high watercut through optimizing the completion strategy. This led to a production gain in this offshore field, which was underperforming as per earlier predictions and expectations. Conventional well-log based qualitative evaluation for horizontal segmentation strategy was rejected in favor of an integrated approach for lateral reservoir facies delineation. Lateral petrophysical property characterization was carried out through quick integration of NMR pore-size driven facies analysis, advanced acoustic radial profiling, anisotropy, and Stoneley analysis. Permeability profiling along the horizontal drain-hole section using NMR and acoustics provided critical insight. Those were integrated to avoid potential high permeability conduits of thief zones for water breakthrough. A rock-quality index was derived to optimize the completion strategy soon after the logging, even preceding the rig-down of the acquisition runs and lowering of the completion. Zones with higher skin, deeper formation damage, and lower rock-mechanical properties were avoided for efficient swell-packer placements. The well started producing and continued production with only 10% water cut along with 450 barrels of oil compared to an average 90% watercut and 100 barrels of oil from the other wells of the same platform, which used the older nonoptimized completion strategy. Based on the promising result for the first well, the same workflow was used for two similar wells of other two different platforms inthe same field, which also resulted in similar production with enhanced oil production and reduced water cut. The study using the rapid integrated evaluation workflow established efficient zonal isolation of high permeability thief zones with accuracy for timely optimization of horizontal well segmentation, which assisted in pulling higher production in this brownfield by reducing unwanted water production.

Pilot Project Evaluating WAG Efficiency for Carbonate Reservoir in Eastern Siberia

2021 ◽  
Author(s):  
Valentina Zharko ◽  
Dmitriy Burdakov
Keyword(s):  
Oil Recovery ◽  
Gas Injection ◽  
Oil Production ◽  
Pilot Project ◽  
Carbonate Reservoir ◽  
Recovery Factor ◽  
Eastern Siberia ◽  
Water Cut ◽  
Wag Injection ◽  
Injection Rates

Abstract The paper presents the results of a pilot project implementing WAG injection at the oilfield with carbonate reservoir, characterized by low efficiency of traditional waterflooding. The objective of the pilot project was to evaluate the efficiency of this enhanced oil recovery method for conditions of the specific oil field. For the initial introduction of WAG, an area of the reservoir with minimal potential risks has been identified. During the test injections of water and gas, production parameters were monitored, including the oil production rates of the reacting wells and the water and gas injection rates of injection wells, the change in the density and composition of the produced fluids. With first positive results, the pilot area of the reservoir was expanded. In accordance with the responses of the producing wells to the injection of displacing agents, the injection rates were adjusted, and the production intensified, with the aim of maximizing the effect of WAG. The results obtained in practice were reproduced in the simulation model sector in order to obtain a project curve characterizing an increase in oil recovery due to water-alternating gas injection. Practical results obtained during pilot testing of the technology show that the injection of gas and water alternately can reduce the water cut of the reacting wells and increase overall oil production, providing more efficient displacement compared to traditional waterflooding. The use of WAG after the waterflooding provides an increase in oil recovery and a decrease in residual oil saturation. The water cut of the produced liquid decreased from 98% to 80%, an increase in oil production rate of 100 tons/day was obtained. The increase in the oil recovery factor is estimated at approximately 7.5% at gas injection of 1.5 hydrocarbon pore volumes. Based on the received results, the displacement characteristic was constructed. Methods for monitoring the effectiveness of WAG have been determined, and studies are planned to be carried out when designing a full-scale WAG project at the field. This project is the first pilot project in Russia implementing WAG injection in a field with a carbonate reservoir. During the pilot project, the technical feasibility of implementing this EOR method was confirmed, as well as its efficiency in terms of increasing the oil recovery factor for the conditions of the carbonate reservoir of Eastern Siberia, characterized by high water cut and low values of oil displacement coefficients during waterflooding.

Review of Practical Experience by Polymer Flooding at Daqing

2009 ◽  
Vol 12 (03) ◽  
pp. 470-476 ◽  
Author(s):  
Dongmei Wang ◽  
Huanzhong Dong ◽  
Changsen Lv ◽  
Xiaofei Fu ◽  
Jun Nie
Keyword(s):  
Oil Production ◽  
Polymer Flooding ◽  
Oil Field ◽  
High Permeability ◽  
Sweep Efficiency ◽  
Molecular Weights ◽  
Well Spacing ◽  
Polymer Flood ◽  
Daqing Oil Field ◽  
Water Cut

Summary This paper describes successful practices applied during polymer flooding at Daqing that will be of considerable value to future chemical floods, both in China and elsewhere. On the basis of laboratory findings, new concepts have been developed that expand conventional ideas concerning favorable conditions for mobility improvement by polymer flooding. Particular advances integrate reservoir-engineering approaches and technology that is basic for successful application of polymer flooding. These include the following:Proper consideration must be given to the permeability contrast among the oil zones and to interwell continuity, involving the optimum combination of oil strata during flooding and well-pattern design, respectively;Higher polymer molecular weights, a broader range of polymer molecular weights, and higher polymer concentrations are desirable in the injected slugs;The entire polymer-flooding process should be characterized in five stages--with its dynamic behavior distinguished by water-cut changes; -Additional techniques should be considered, such as dynamic monitoring using well logging, well testing, and tracers; effective techniques are also needed for surface mixing, injection facilities, oil production, and produced-water treatment; andContinuous innovation must be a priority during polymer flooding. Introduction China's Daqing oil field entered its ultrahigh-water-cut period after 30 years of exploitation. Just before large-scale polymer-flooding application, the average water-cut was more than 90%. The Daqing oil-field is a large river-delta/lacustrine facies, multilayered with complex geologic conditions and heterogeneous sandstone in an inland basin. After 30 years of waterflooding, many channels and high-permeability streaks were identified in this oil field (Wang and Qian 2002). Laboratory research began in the 1960s, investigating the potential of enhanced-oil-recovery (EOR) processes in the Daqing oil field. After a single-injector polymer flood with a small well spacing of 75 m in 1972, polymer flooding was set on pilot test. During the late 1980s, a pilot project in central Daqing was expanded to a multiwell pattern with larger well spacing. Favorable results from these tests--along with extensive research and engineering from the mid-1980s through the 1990s--confirmed that polymer flooding was the preferred method to improve areal- and vertical-sweep efficiency at Daqing and to provide mobility control (Wang et al. 2002, Wang and Liu 2004). Consequently, the world's largest polymer flood was implemented at Daqing, beginning in 1996. By 2007, 22.3% of total production from the Daqing oil field was attributed to polymer flooding. Polymer flooding boosted the ultimate recovery for the field to more than 50% of original oil in place (OOIP)--10 to 12% OOIP more than from waterflooding. At the end of 2007, oil production from polymer flooding at the Daqing oil field was more than 10 million tons (73 million bbl) per year (sustained for 6 years). The focus of this paper is on polymer flooding, in which sweep efficiency is improved by reducing the water/oil mobility ratio in the reservoir. This paper is not concerned with the use of chemical gel treatments, which attempt to block water flow through fractures and high-permeability strata. Applications of chemical gel treatments in China have been covered elsewhere (Liu et al. 2006).

Polymer Injection to Unlock Bypassed Oil in a Giant Carbonate Reservoir: Bridging the Gap Between Laboratory and Large Scale Polymer Project

2021 ◽  
Author(s):  
Clement Fabbri ◽  
Haitham Ali Al Saadi ◽  
Ke Wang ◽  
Flavien Maire ◽  
Carolina Romero ◽  
...  
Keyword(s):  
High Salinity ◽  
Water Injection ◽  
Cross Flow ◽  
Carbonate Reservoir ◽  
Carbonate Reservoirs ◽  
Laboratory Work ◽  
High Permeability ◽  
Polymer Injection ◽  
Single Well ◽  
Pilot Design

Abstract Polymer flooding has long been proposed to improve sweep efficiency in heterogeneous reservoirs where polymer enhances cross flow between layers and forces water into the low permeability layers, leading to more homogeneous saturation profile. Although this approach could unlock large volumes of by-passed oil in layered carbonate reservoirs, compatibility of polymer solutions with high salinity - high temperature carbonate reservoirs has been hindering polymer injection projects in such harsh conditions. The aim of this paper is to present the laboratory work, polymer injection field test results and pilot design aimed to unlock target tertiary oil recovery in a highly heterogeneous mixed to oil-wet giant carbonate reservoir. This paper focuses on a highly layered limestone reservoir with various levels of cyclicity in properties. This reservoir may be divided in two main bodies, i.e., an Upper zone and a Lower zone with permeability contrast of up to two orders of magnitude. The main part of the reservoir is currently under peripheral and mid-flank water injection. Field observations show that injected water tends to channel quickly through the Upper zone along the high permeability layers and bypass the oil in the Lower zone. Past studies have indicated that this water override phenomenon is caused by a combination of high permeability contrast and capillary forces which counteract gravity forces. In this setting, adequate polymer injection strategy to enhance cross-flow between these zones is investigated, building on laboratory and polymer injection test field results. A key prerequisite for defining such EOR development scenario is to have representative static and dynamic models that captures the geological heterogeneity of this kind of reservoirs. This is achieved by an improved and integrated reservoir characterization, modelling and water injection history matching procedure. The history matched model was used to investigate different polymer injection schemes and resulted in an optimum pilot design. The injection scheme is defined based on dynamic simulations to maximize value, building on results from single-well polymer injection test, laboratory work and on previous published work, which have demonstrated the potential of polymer flooding for this reservoir. Our study evidences the positive impact of polymer propagation at field scale, improving the water-front stability, which is a function of pressure gradient near producer wells. Sensitivities to the position and number of polymer injectors have been performed to identify the best injection configuration, depending on the existing water injection scheme and the operating constraints. The pilot design proposed builds on laboratory work and field monitoring data gathered during single-well polymer injection field test. Together, these elements represent building blocks to enable tertiary polymer recovery in giant heterogeneous carbonate reservoirs with high temperature - high salinity conditions.

scholarly journals New Waterflooding Characteristic Curves Based on Cumulative Water Injection

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Zhiwang Yuan ◽  
Zhiping Li ◽  
Li Yang ◽  
Yingchun Zhang
Keyword(s):  
Characteristic Curve ◽  
Water Injection ◽  
Material Balance ◽  
Oil Production ◽  
High Water ◽  
Difficult Problem ◽  
Prediction Errors ◽  
High Water Cut Stage ◽  
High Water Cut ◽  
Water Cut

When a conventional waterflooding characteristic curve (WFCC) is used to predict cumulative oil production at a certain stage, the curve depends on the predicted water cut at the predicted cutoff point, but forecasting the water cut is very difficult. For the reservoirs whose pressure is maintained by water injection, based on the water-oil phase seepage theory and the principle of material balance, the equations relating the cumulative oil production and cumulative water injection at the moderately high water cut stage and the ultrahigh water cut stage are derived and termed the Yuan-A and Yuan-B curves, respectively. And then, we theoretically analyze the causes of the prediction errors of cumulative oil production by the Yuan-A curve and give suggestions. In addition, at the ultrahigh water cut stage, the Yuan-B water cut prediction formula is established, which can predict the water cut according to the cumulative water injection and solve the difficult problem of water cut prediction. The application results show Yuan-A and Yuan-B curves are applied to forecast oil production based on cumulative water injection data obtained by the balance of injection and production, avoiding reliance on the water cut forecast and solving the problems of predicting the cumulative oil production of producers or reservoirs that have not yet shown the decline rule. Furthermore, the formulas are simple and convenient, providing certain guiding significance for the prediction of cumulative oil production and water cut for the same reservoir types.

Polymer-Flooding-Pilot Learning Curve: Five-Plus Years' Experience To Reduce Cost per Incremental Barrel of Oil

2014 ◽  
Vol 18 (01) ◽  
pp. 11-19 ◽  
Author(s):  
J.. Buciak ◽  
G.. Fondevila Sancet ◽  
L.. Del Pozo
Keyword(s):  
Learning Curve ◽  
Produced Water ◽  
Water Injection ◽  
Oil Production ◽  
Polymer Flooding ◽  
Oil Field ◽  
High Porosity ◽  
Polymer Injection ◽  
Injection Pump ◽  
Water Cut

Summary This paper deals with the learning curve of a five-plus-year polymer-flooding pilot conducted in a mature waterflood that includes, for example, several works related to injector and producer wells and reservoir management. The scope of this paper is to describe the learning curve during the last 5 years rather than the reservoir response of the polymer-flooding technique; focus is on the aspects related to reduce cost per incremental barrel of oil for a possible extension to other waterflooded areas of the field. Diadema oil field is in the San Jorge Gulf basin in the southern portion of Argentina. The field is operated by CAPSA, an Argentinean oil-producer company; it has 480 producer and 270 injector wells (interwell spacing is 250 m on average). The company has developed waterflooding over more than 18 years (today, this technique represents 82% of oil production in the field) and produces approximately 1600 m3/d of oil and 40 000 m3/d of gross production (96% water cut) with 38 400 m3/d of water injection. The reservoir that is polymer-flooded is characterized by high permeability (average of 500 md), high heterogeneity (10 to 5,000 md), high porosity (30%), very stratified sandstone layers (4 to 12 m of net thickness) with poor lateral continuity (fluvial origin), and 20 °API oil (100 cp at reservoir conditions). Diadema's polymer-flooding pilot started in October 2007 on five water injectors (it includes 13 injectors today) with an injected rate of 1000 m3/d (today, 2000 m3/d). Polymer solution is made with produced water (15,000 ppm brine) and 1,500 ppm of hydrolyzed polyacrylamide polymer reaching 15- to 20-cp fluid-injection viscosity. Oil-production rate from the original “central” producers (wells that are aided with 100% of polymer injection) has increased 100% at the same time as average reduction in water cut is approximately 15%. The main aspects presented in this work are depth profile modification with crosslinked gel injected along with polymer, use of “curlers” to regulate injection in multiple wells with one injection pump without shearing the polymer, and an improved technology on producer wells with progressing-cavity pumps to decrease shut-in time and number of pump failures. The plan for the future is to extend this project to other areas with the acquired knowledge and to improve different aspects, such as water quality and optimization of polymer plant operation. These improvements will allow the company to reduce operating costs per incremental barrel of oil.

Approach to Hydrodynamic Modeling of In-Situ Combustion in Carbonate Reservoir Based on the Results of Laboratory Studies and Preliminary Works for Pilot Test

2021 ◽  
Author(s):  
Kirill Igorevich Maksakov ◽  
Natalia Valerievna Lesina ◽  
Konstantin Aleksandrovich Schekoldin
Keyword(s):  
Dynamic Modeling ◽  
Cold Water ◽  
Oil Production ◽  
Integrated Approach ◽  
Carbonate Reservoir ◽  
Injection Well ◽  
Laboratory Studies ◽  
Technological Parameters ◽  
In Situ Combustion

Summary For the purpose of this work, the authors used an integrated approach to the modeling of in-situ combustion (ISC) including the results of laboratory studies and preliminary works, which significantly affect the choice of the method for implementing ISC and the results obtained in the process of modeling. The laboratory studies provided the data on the temperature range of the beginning of high-temperature oil oxidation, which is to be achieved during the modelling of the bottomhole zone heating. Based on the resulting injectivity profile, the reservoir distribution within the injection well zone in the geological model was updated. A high-permeability channel between the injection well and one of the production wells revealed during cold water injection explains the main oil production increment resulting from ISC and demonstrated by the reservoir simulation model. Based on the results of model runs for a more uniform distribution of the effect between producing wells, the best start-up time for the most reactive well was determined. Using dynamic modeling of in-situ combustion in a carbonate reservoir, the parameters of this technology implementation were found, and incremental oil production was estimated. For the first time, the ISC technology is planned for implementation in a carbonate reservoir with high-viscosity oil in Samara region. The developed integrated approach to the dynamic modeling of in-situ combustion, which considers both the laboratory studies and preparatory work data, enables the most accurately determination of the best ISC technological parameters and this technology contribution.

Cyclic Water Injection Improves Oil Production in Carbonate Reservoir

2008 ◽  
Author(s):  
Leonid M. Surguchev ◽  
Nils Harald Giske ◽  
Lars Kollbotn ◽  
Anton Shchipanov
Keyword(s):  
Water Injection ◽  
Oil Production ◽  
Carbonate Reservoir

A Method to Determine the Optimal Water Injection Intensity Based on Oil Production Rate and Water Cut

2012 ◽  
Vol 594-597 ◽  
pp. 2442-2445 ◽  
Author(s):  
Ji Cheng Zhang ◽  
Ying Jia ◽  
Xiao Na Cui
Keyword(s):  
Production Rate ◽  
Water Injection ◽  
Oil Production ◽  
Water Flooding ◽  
Water Intensity ◽  
Water Cut ◽  
Relationship Of ◽  
The Relationship ◽  
Oilfield Development ◽  
Zone Water

Water injection is one of the important ways to maintain reservoir pressure and improving the oilfield development effect. And separate zone water injection is the main technology in water flooding oilfield. The optimal water intensity which has been allocated plays an important role in all kinds of reservoir. This paper proposed a method to optimize the water injection intensity based on oil production rate and water cut. Conceptual model was constructed on the basis of real reservoir. By numerical simulation, a chart board was derived which describes the relationship of water injection intensity versus oil production rate and water cut. Using this chart, we can determine the optimal water injection intensity on different oil production rate and water cut.

Adaptability Study on Plugging Thief Zones with Asphalt Particle in Polymer Flooding Offshore Field

2014 ◽  
Author(s):  
K.. Xiao ◽  
H.. Jiang ◽  
Q.. Wang ◽  
H.. Wang ◽  
D.. Zhao
Keyword(s):  
Numerical Model ◽  
Numerical Simulations ◽  
Oil Recovery ◽  
Negative Impact ◽  
Oil Production ◽  
Polymer Flooding ◽  
High Permeability ◽  
Sweep Efficiency ◽  
Water Cut ◽  
Offshore Field

Abstract Polymer flooding has been proved to be an effective method for improving oil recovery in offshore field of Bohai area, but thief zones with high permeability could make the effect of polymer on oil production worse. To try to minimize the negative impact brought by thief zones, we apply asphalt particle to plug the high permeability regions to compel subsequent displacement fluid change flowing direction to enhance sweep efficiency. Its adaptability is studied by a series of parallel cores flooding. Besides, numerical simulations are carried out to optimize pattern of asphalt particle injection and evaluate the performances of asphalt flooding in a typical well group in Bohai area in a numerical model. In addition to performances of water cut and oil recovery for the parallel core flooding, we present dynamic features of remaining oil from micro views detected by nuclear magnetic resonance. By plugging thief zone by asphalt flooding, oil production is improved. Production in small and medium pores is increased by asphalt flowing into big pores to exert strong resistance on them. Also, with numerical simulations, optimal way of injecting asphalt has been selected to lead the operation in field. Through observation of a typical well group under asphalt injection in numerical model based on real reservoir, the water-cut and oil production are decrease 9.7% and increase 29.1m3/d respectively. We conclude that asphalt particle has good capacity to plug thief zones to improve sweep efficiency of subsequent displacement fluid in polymer flooding field. In-depth understanding such mechanisms for asphalt particle behavior may be pivotal for enhancing oil recovery in polymer flooding reservoir containing thief zones.

60 Years Field Performance Data-Driven Analytics to Generate Updated Waterflood Field Development Plan in a North Kuwait Giant Carbonate Reservoir

2021 ◽  
Author(s):  
Basel AL-Otaibi ◽  
Issa Abu Shiekah ◽  
Manish Kumar Jha ◽  
Gerbert de Bruijn ◽  
Peter Male ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Water Injection ◽  
Oil Production ◽  
Horizontal Wells ◽  
Carbonate Reservoir ◽  
Development Plan ◽  
Data Driven ◽  
Water Flooding ◽  
Field Development ◽  
The Impact

Abstract After 40 years of depletion drive, a mature, giant and multi-layer carbonate reservoir is developed through waterflooding. Oil production, sustained through infill drilling and new development patterns, is often associated with increasingly higher water production compared to earlier development phases. A field re-development plan has been established to alleviate the impact of reservoir heterogeneities on oil recovery, driven by the analysis of the historical performance of production and injection of a range of well types. The field is developed through historical opportunistic development concepts utilizing evolving technology trends. Therefore, the field has initially wide spacing vertical waterflooding patterns followed by horizontal wells, subjected to seawater or produced water injection, applying a range of wells placement or completion technologies and different water injection operating strategies. Systematic categorization, grouping and analyzing of a rich data set of wells performance have been complemented and integrated with insights from coarse full field and conceptual sector dynamic modeling activities. This workflow efficiently paved the way to optimize the field development aiming for increased oil recovery and cost saving opportunities. Integrated analysis of evolving historical development decisions revealed and ranked the primary subsurface and operational drivers behind the limited sweep efficiency and increased watercut. This helped mapping the impact of fundamental subsurface attributes from well placement, completion, or water injection strategies. Excellent vertical wells performance during the primary depletion and the early stage of water flooding was slowly outperformed by a more sustainable horizontal well production and injection strategy. This is consistent with a conceptual model in which the reservoir is dominated by extensive high conductive features that contributed in the early life of the field to good oil production before becoming the primary source of premature water breakthrough after a limited fraction of pore volume water was injected. The next level of analysis provided actual field evidence to support informed decisions to optimize the front runner horizontal wells development concept to cover wells length, orientation, vertical placement in the stratigraphy, spacing, pattern strategy and completion design. The findings enabled delivering updated field development plan covering the field life cycle to sustain and increase field oil production through adding ~ 200 additional wells and introducing more structured water flooding patterns in addition to establishing improved wells reservoir management practices. This integrated study manifests the power, efficiency and value from data driven analysis to capture lessons learned from evolving wells and development concepts applied in a complex brown field over six decades. The workflow enabled the delivery of an updated field development plan and production forecasts within a year through utilizing data analytics to compensate for the recognized limitations of subsurface models in addition to providing input to steer the more time-consuming modeling activities.

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