bluuebunny/crossref_metadata_2025_split huggingface dataset:
Successful Application of Engineered High Temperature Resistant Cement in a steam flood injection project in Bahrain
Authors: Pohl Jonathan , Jain Bipin , Al-Hawaj Husain , Shehab Ali , Sultan Hussain , Al-Tarif Nazar , Sayed AlGhani 
Published: February 2017

Abstract
Depletion of conventional hydrocarbons reservoirs have led oil and gas operators to extend the boundaries and pursue production from reservoirs with high viscosity hydrocarbons that in the past were impossible to be produced and allow the hydrocarbons in place to flow to the surface with conventional production methods. With the introduction of enhance oil recovery techniques (EOR) operators has been able to economically produce from these reservoirs. The steam flood is an EOR technique that allows heavy oil hydrocarbons to be produced and increase the recovery of original oil in place (OOIP). This technique requires high temperature steam to be injected into the reservoir in order to allow hydrocarbons production, introducing challenges in order to maintain well integrity and long term life of the well. Suitable surface facilities, equipment and materials that withstand these challenging conditions are required in order to guarantee the success of the project. In a heavy oil shallow reservoir in Bahrain, a steam flood pilot project has been executed, injecting steam up to 650ºF into the injectors wells in order to enhance the hydrocarbons production in the adjacent production wells. Conventional cement systems will fail when exposed to the given conditions as the mechanical properties of such cements are not sufficient to withstand the stresses created in this extreme temperature environment. This will consequently threaten the well integrity and success of the project. In order to provide a reliable and durable zonal isolation, an engineered cement system has been introduced. This cement system possesses sufficient flexibility (low Young's modulus), and a high coefficient of thermal expansion to withstand the metal casing expansion during the heating step of the process, without failure. This cement system exhibits stable mechanical properties for a long duration during the whole process of the heavy oil production and can be mixed and pumped with conventional cementing equipment. It is placed at low (110-140°F) temperature, acquires sufficient compressive and tensile strength to withstand the heating cycles. Over 50 wells have been cemented using this technology in Bahrain. Cement bond longs and temperature logs demonstrate well integrity has been achieved, allowing the steam to be injected into the target reservoir. Furthermore, no issues have been seen related to steam break through to surface. The project has been implemented for over 4 years with no sign of wellbore integrity failure. This study covers several aspects of the design, execution and evaluation of the cement system.
Experimental Research On Gravity Water-Drainage Assisted Steam Flooding in Extra and Super Heavy Oil Development
Authors: Wu Xiaoming , Sun Shouguo , Zhang Hongjun , Sun Zhenyu , Yang Baochun , Wang Ying , Jiang Hua , Wang Lei 
Published: February 2017

Abstract
With the increase of CSS cycles and decline of production, some reservoirs cannot be converted to steam flooding or SAGD production due to their characteristics, limiting the development effect of this kind of reservoirs. Therefore, steam flooding has been combined with SAGD on a trial basis, forming the gravity water-drainage assisted steam flooding technique, which has successfully solved the problem of how to produce this kind of reservoirs at their later production stage. The technique uses the combination of vertical wells plus horizontal wells. A paired horizontal wells are configured in the same way as those in SAGD and a corresponding number of vertical wells are distributed around the horizontal wells. The upper horizontal well is used for steam injection and the lower one is used for water production and the surrounding vertical wells are used for oil production. During steam drive, low steam quality at the bottomhole due to high bottomhole pressure can lead to serious water production, which can be eliminated with this technique. The technique was tested in one well group in Block Wa59 which is a mid-deep extra and super heavy oil reservoir. The vertical gap between the paired horizontal wells is 20m, 50m between vertical wells and horizontal wells and 70m between the vertical wells. Some matching technological measures were provided, such as dual pipe steam injection pipestring for solving the uneven steam injection problem, deep pumping and high temperature large displacement lifting for eliminating pressure drop during fluid lifting, which ensured the results of gravity water drainage assisted steam flooding test. The test has resulted in obvious incremental oil production and water reduction with fluid production increased from 179t/d to 526t/d, oil production increased from 31.0t/d to 96.5t/d and watercut dropped from 91.1% to 84.69%. The technique has provided a new way for reservoirs not suitable for converting to steam flooding or SAGD development. It will be used widely in Liaohe Oilfield and other crude oil fields.
Learnings from the Grand Rapids Field Trial of Tubing Deployed Inflow Control Devices for SAGD Application
Authors: Dragani J. M. , Drover K. T. , Zhang X. C. 
Published: February 2017

Abstract
Field trials of tubing deployed Inflow Control Devices (ICDs) were conducted at the Grand Rapids SAGD Pilot from 2014 to 2016. The objective of the trials were to evaluate the flow performance of ICDs in a tubing deployed completion and assess improvements to thermal conformance. Key performance metrics were established to monitor changes in well performance, including production rates, thermal conformance, steam production and Steam to Oil Ratio (SOR). A comprehensive study was undertaken after the trials concluded. Multiple approachs were taken including analytical representations and simulations. The purpose of the study was to improve understanding of the underlying physics that govern flow and thermodynamic behavior of ICDs. The study specifically addressed restriction effects for various inflow conditions, steam flashing effects through the devices and heat exchange effects associated with the completion design. The results of the study identify some design principles that may be used for future application of ICDs in SAGD wells.
Well Pairs 1 and 2 at the Grand Rapids Pilot project were used to test different ICD completions in a SAGD well pair. The Well Pair 1 field trial began first and lasted seven months. Learnings from the Well Pair 1 trial were extended to the Well Pair 2 trial which lasted 18 months. Flowing and shut-in temperature profiles were collected to understand near wellbore conditions and 4D seismic was used to ascertain changes to thermal conformance in the reservoir. Analytical and numerical models were developed to match field observations from the trial. Results from the field trial provided unique learnings with respect to the benefits that tubing deployed ICD systems may provide for SAGD wells. Changes in conformance and temperature distribution in the lateral sections were noted with little to no uplifts in oil rates or SOR.
Once the trials were complete, all ICDs were removed from both well pairs and subject to visual inspections. Thereafter, a sample population of devices underwent a series of tests to evaluate mechanical integrity. The tests also characterized any changes to ICD flow relationships before and after the trial. Inspections of the devices post-operation provided crucial learnings on the mechanical integrity of such systems.
Selection of New Generation Chemicals as Steam Additive for Cost Effective Heavy-Oil Recovery Applications
Authors: Wei You , Babadagli Tayfun 
Published: February 2017

Abstract
One of the ways to improve the efficiency of steam injection is to use chemicals as an additive to alter interfacial properties. Historically, this has been tested using surfactants, which are expensive and thermally unstable. Therefore, commercial applications have been highly limited in that area over the past three decades. In conjunction with recent efforts using new generation materials as EOR agents, we performed a screening study to identify the potential chemicals/materials for heavy-oil recovery and to investigate the applicability of selected new generation chemicals as interfacial properties modifiers at steam temperature.
Different experimental methods, including capillary imbibition tests, i.e. contact angle and interfacial tension measurements, were combined to understand the mechanism of alteration surface interplay (wettability and interfacial tension) using different chemical agents. Capillary imbibition tests were conducted to study the potential of these chemicals to alter wettability and rock/chemical interactions on limestone and aged sandstone cores at high temperature. Pendant drop interfacial tension (IFT) and contact angle measurements were performed using a high pressure and high temperature cell under the same -steam- conditions.
Seven different chemical agents including a high pH solution (sodium metaborate), an ionic liquid, a cationic and an anionic surfactant, and nanofluids (aluminum and zirconium oxides) were tested in this study. Indiana limestone samples were saturated and aged in heavy oil with a viscosity of 6,000 cp. Capillary imbibition tests were conducted under high temperature (between 90°C and 180°C) and high pressure (185 psi) conditions using a newly-manufactured visual cell. The production rate and ultimate recovery were used to evaluate the capability of different chemicals changing the interfacial properties and their thermal stability at steam temperature. Contact angles between heavy oil and calcite plates were measured under the same conditions. Finally, the stability of the chemicals was measured through settlement tests at steam temperature conditions as well as TGA (thermal gravimetric analysis). The combination of all these results helped identify the applicability of the selected chemicals under steam conditions for carbonates. Technical and economic limitations for each chemical as well as the way the chemical contributes to recovery (wettability alteration or IFT reduction) were identified.
Investigation of interfacial properties alteration induced by new generation chemicals at high temperature is helpful in the selection and application of efficient and economical chemicals in steam based heavy-oil recovery methods.
Application of Multiazimuth Vertical Planes MAVP to In-Situ Extraction of Heavy Oil from Shallow and Stranded Oil Sands
Authors: Jamali Ali , Soliman Mohamed Y. , Shahri Mehdi , Cavender Travis 
Published: February 2017

Abstract
Throughout the past five decades, the heavy oil industry has developed various in-situ techniques for oil recovery from the vast global heavy oil reserves. The diversity of these techniques goes hand in hand with the diversity of the world reserves in terms of viscosity, burial depth, and reservoir complexity. Reservoirs exist, however, wherein the currently available commercial methods might not be technically and economically feasible. In particular, reservoir quality and caprock integrity can impose significant limitations on the feasibility of conventional methods, such as steam assisted gravity drainage (SAGD). This paper summarizes the results of a series of field trials in weakly cemented formations based on the creation of highly conductive multiazimuth vertical planes (MAVP) in soft formations. These planes are mechanically initiated and hydraulically propagated and have typical dimensions of 0.03×5×30 m and can be used in a new steam injection design. The potential application of this technique to enhanced oil recovery is investigated using a thermal reservoir simulator.
Reservoir simulations show promising results in terms of cumulative steam oil ratio (CSOR) and oil production rate. Stabilized production was observed immediately after the startup and CSOR dropped to under 3.0 m3/m3 in less than two years. The overall performance is nearly comparable to that of conventional SAGD, while it outperforms SAGD in certain conditions, including low vertical permeability and in the presence of low permeable shale streaks. Simulation results show that the performance of MAVP is nearly unimpaired when planes’ projection is discontinuous in either vertical or horizontal directions. The results also showed that the presence of a confined top water zone does not have a detrimental impact on the performance of MAVP; however, penetration into the top water zone must be avoided to achieve the best results in terms of CSOR. While surface mining and variations of SAGD are respectively used for very shallow and relatively deep reservoirs, the new methodology is applicable to reservoirs in the depth range of 70 to 600 m, where weak caprock integrity can impose a significant challenge. In addition, complex reservoir features, such as the presence of low permeable shale layers or low vertical permeability, have minimal effect on the performance of this technique.
Characterizing Unconsolidated Heavy Oil Sands Using Cryogenic MicroCT - A Pilot Study from Kuwait
Authors: Ahmed K. , Ferdous H. , Jain A. K. , Ahmad F. , Golab A. , Deakin L. , Young B. , Mascini A. 
Published: February 2017

Abstract
Conventional analysis on core plugs from unconsolidated heavy oil sands is challenging to perform. Sometimes doubts exist about whether the results are representative of the in-situ rock fabric. A digital rock pilot study was designed to provide unique data to understand the rock and allow independent verification of laboratory data, such as calculated petrophysical properties, characterization of damage associated with coring and preservation, direct imaging of oil distribution and pore-wall wettability, and characterization of pore types, clays, grains and grain contacts.
The pilot study presents successful cryogenic helical X-ray micro-computed tomography (microCT) of preserved plugs maintained in the frozen state throughout the imaging process. Those 3D images were processed to calculate porosity and absolute permeability. Direct imaging of oil distribution by 3D microCT, with X-ray contrasting agents to highlight the oil with complementary characterization of pore-wall wettability by secondary electron Field Emission Scanning Electron Microscopy (FESEM) is presented to confirm observations from the 3D microCT imaging. Finally, Back scattered SEM (BSEM) imaging and automated, quantified mineral mapping are presented.
The 3D tomograms from cryogenic microCT imaging were analysed based on morphological characteristics to identify damaged zones, representing &gt;30% of the volume. The calculated absolute permeability of those 3D tomograms ranged from 8.50D to 24.8D across the plug. The undamaged region had distinctly lower kabs (average = 9.71D) than the most damaged region (average = 21.6D), compared to measurements by a traditional laboratory on adjacent screened and cleaned plugs reported as &gt;20D. The oil saturation from direct microCT imaging was 76.3%, compared to conventional core analysis of oil saturation on a sister plug (62.1%). The 3D images show oil filling most of the open pores and the pore-filling and porous minerals. Furthermore, the oil appears to be in direct contact with the mineral grains, indicating that oil is the wetting phase. Wettability imaging by FESEM confirmed that the majority of the mineral surfaces are oil-wet but the layers of asphaltenes are thin. The mineral composition is dominated by quartz (81%) and feldspar (16%) with some minor clay (1.7%) and carbonate (0.3%). The mineralogy indicates that the sample is likely to be unreactive to steam and/or chemical stimulants.
Experimental Investigation of Metal-to-Metal Seal Behavior in Premium Casing Connections for Thermal Wells
Authors: Xie Jueren , Matthews Cam 
Published: February 2017

Abstract
Thermal well service conditions have presented a significant challenge to the sealability of casing connections. Over the years, industry has established various standards, protocols and guidelines for assessing the sealability performance of casing connections to be used in thermal well applications. The use of Finite Element Analysis (FEA) has been increasingly incorporated into the connection performance evaluation process. FEA evaluation requires the use of an appropriate criterion that relates the connection seepage rates to the applied internal pressure differential, contact stress profile on the radial seal surface, surface roughness, thread compounds and various other factors such as environmental impacts.
This paper presents experimental work that has been undertaken to investigate the metal-to-metal seal behavior in premium casing connections. The physical tests simulated a series of metal-to-metal seals under various levels of gas pressure and seal contact stress. The impacts of seal length, tubular diameter, surface roughness, thread compound and corrosive medium were investigated. The experimental results were used to validate the sealability criterion which is proposed for use in evaluating thermal well casing connections.
A Fractional Flow Theory for Unstable Immiscible Floods
Authors: Luo Haishan , Delshad Mojdeh , Zhao Bochao , Mohanty Kishore K. 
Published: February 2017

Abstract
Conventional fractional flow theories such as the Buckley-Leverett analysis have benefited reservoir engineers greatly for many decades. Although being simple, these analyses provide prompt and decent estimations of water breakthrough and oil bank height/duration in the experiments and the fields. However, their intrinsic inaccuracy in estimating unstable immiscible floods due to the existence of viscous fingering has long been ignored. With increasing non-thermal immiscible floods developed for heavy oil reservoirs, an essential improvement for such a theory is desirable.
The intrinsic residual oil saturation can never be achieved for strong unstable immiscible floods within a finite time. The fraction of the bypassed oil at a time is highly dependent on the viscosity ratio, flow velocity, interfacial tension, wettability, permeability and the geometry of the rock. Extensive experimental data and numerical studies have indicated that the strength and growth rate of viscous fingering are correlated to a dimensionless number, i.e., the viscous finger number, which is an integration of those factors aforementioned. Such a discovery enables a quantitative establishment of two-phase pseudo relative permeabilities, which are functions of fluid saturations and the viscous finger number. The fractional flow for unstable floods can hence be obtained by use of such pseudo relative permeabilities.
The new fractional flow theory extended from the Buckley-Leverett analysis was applied to several groups of heavy-oil water coreflood experiments under various conditions. The new fractional flow analysis was able to predict very well the breakthrough time and oil recovery of these experiments. We further applied the new fractional flow analysis to a slab experiment of viscous oil with a waterflood followed by a polymer flood, and achieved a very good agreement with the oil recovery data. The analysis reproduced that the water cut increased very rapidly and the remaining oil saturation was much larger than the intrinsic residual oil saturation after several pore volumes of waterflood. The subsequent polymer flood altered the pseudo relative permeability curves due to the change of viscosity ratio and brought in a considerable amount of mobile oil to be displaced. This process happens to be similar to the fractional flow of low-tension immiscible flow. Such a scenario is different from what the conventional fractional flow analysis suggests, which neglects the fact that the subsequent polymer flood is able to greatly improve the oil cut by mitigating the viscous fingers originally created by waterflood.
The new theory has extended the original fractional flow theories to unstable immiscible floods, a major progress. It can also serve as a critical guideline to estimate and predict the water/polymer breakthrough and the oil production in viscous-oil benchscale experiments and field projects.
An Experimental Evaluation of Pore Plugging and Permeability Reduction Near SAGD Sand Control Liners
Authors: Mahmoudi Mahdi , Fattahpour Vahidoddin , Nouri Alireza , Leitch Michael 
Published: February 2017

Abstract
This paper presents the results of an experimental investigation to determine the mechanisms of pore plugging and permeability reduction near SAGD screen liners. The aim is to arrive at a liner design that maximizes wellbore productivity without compromising the sand control function of the liner.
We set up a large-scale Sand Retention Testing (SRT) facility that accommodates a multi-slot liner coupon at the base of a sand-pack with representative grain shape and particle size distribution (PSD) of typical oil sands. Brine is injected at different flow rates and pressure differences across the coupon and the sand-pack as well as the mass and PSD of the produced sand and fines are measured during the test. Further, the PSD and concentration of migrated fines (&lt;44 microns) along the sand-pack are determined in a post-mortem analysis. The testing results are used to assess the effect of slot size and slot density on the sand control performance as well as pore-plugging and permeability alterations near the sand-control liner.
We observed that the slot size, slot density and flow rate highly affect the concentration and PSD of produced fines as well as accumulated fines (pore clogging) above the screen. For the same flow rates and total injected pore volume, wider screen aperture and higher slot density result in lower fines accumulation above the screen but more sanding. Further, the variation of slot density alters the flow convergence behind the slots, hence, the size and concentration of mobilized fines. Results indicate that higher fines concentration near the screen reduces the retained permeability, hence, lowers the wellbore productivity.
This paper provides a new insight into pore plugging and fines migration adjacent the sand control liner. It also introduces a new testing method to optimize the design of sand control liners for minimum productivity impairment in SAGD projects.