bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimization of CO2 WAG Processes in a Selected Carbonate Reservoir-An Experimental Approach
Authors: Amin Mohamed E. , Zekri Abdulrazag Y. , Almehaideb Reyadh , Al-Attar Hazim 
Published: November 2012

Abstract
Miscible gas flooding using carbon dioxide is currently being investigated as a possible EOR process for a number of United Arab Emirates (UAE) reservoirs. It has high potential to improve oil recovery in addition to possibly utilizing most of the carbon dioxide emissions from industrial sources. The major factors affecting implementation of CO2 floods are the availability of CO2 at economic prices (generally within 2-3 $/MSCF) and the net utilization ratio of CO2 per barrel of additional oil recovered. Typical net utilization of CO2 for well-designed floods vary from field to field but on average has been estimated at 5.5 MSCF CO2 per additional barrel of oil in a US EOR overview study by Broome et al.1 and between 4-6 MSCF/barrel by a more recent study by Jeschke et al.2. At other fields it might be as high as 15 MSCF/barrel or more. Minimizing net utilization requires controlling the high mobility ratio for miscible gas injection which causes lower sweep due to gas channeling and by-passing of the oil in the reservoir. To control the mobility ratio, the Water-Alternating CO2-Gas (WAG) technique is proposed by injecting alternately small solvent [CO2] and water slugs. The slug of water reduces the speed of the solvent and solvent fingering thus improving the mobility ratio of the injected fluids to fluids in place.
The objective of this work is to experimentally assess the recovery of oil with CO2 injection in a selected UAE carbonate reservoir. Two types of CO2-flooding experiments were conducted, continuous miscible CO2 injection and CO2-WAG injection using a specialized experimental rig. The effects of changing the CO2-Water ratio and WAG timing on the overall performance of the flood were investigated. All laboratory tests were conducted under controlled conditions of pressure and temperature corresponding to field conditions. Results of this laboratory investigation reveal a general trend of improved oil recovery with increased volume of CO2 inside core samples during the flood process. The observed ultimate oil recoveries range from 52 percent with continuous water injection to 72 percent of the original oil in place with continuous CO2 injection over the full period of the experiment with recoveries of the CO2-WAG floods falling in between. The optimum CO2-WAG ratio was found to occur at 1:2.
The outcomes of this work should contribute to our understanding of WAG CO2 floods for the UAE reservoirs and supports the ongoing R&D efforts made by the operating oil companies in the UAE towards application of CO2-WAG floods
Workplace monitoring in ADGAS - A step towards employee wellbeing
Authors: Sarkar Prabir , Al-Ali Asiyah , Roy Soumen , Zamzam Mohamed 
Published: November 2012

Abstract
ADGAS has undertaken a quantitative evaluation of the priority chemical hazards identified in its Occupational Health risk assessment study. The major hazards identified included; BTEX (Benzene, Toluene, Ethyl Benzene & Xylene), Hydrogen Sulphide, Welding fumes & paints containing di-isocyanates. In the Product Quality Department, exposure to BTEX and its metabolites & hydrogen sulphide were monitored for Product Analysts. Exposure to welding fume contaminants & particulates were monitored for welders and fabricators. Estimation of di-isocyanates exposure while performing painting operations was also carried out in the General Technical Services Department.
The quantification of occupational hazards was used to determine health risks from exposure to potentially hazardous substances. The data also served in the preparation of a structured occupational hygiene monitoring plan, as a follow-up to the recommendations of the Occupational Health Risk Assessment. Level of exposure to all the hazardous components were found to be well within the prescribed ACGIH threshold limit values, thus suggesting negligible levels of risk for the employees involved in the concerned operations.
Despite the low exposure levels, the workplace monitoring has led to a thorough evaluation and implementation of better work practices (E.g. mandatory use of Self Containing Breathing Apparatus for Product analysts, while sampling H2S) & conditions (E.g. balancing of fume hoods for improved capture of contaminants in the Product Quality Department) leading to a further minimization of health risks.
In the first place, the monitoring programme has enabled ADGAS to adhere to the ADNOC Code of Practice requirements. Secondly, this has been a step forward in ensuring the wellbeing of exposed working group and remaining in tune with the management commitment for the pursuit of higher HSE standards and ensuring higher productivity and employee satisfaction.
Integration of Drilling, Completion, and Stimulation Technology Boosts Saudi Arabian Gas Well Performance
Authors: Rahim Zillur , Al-Kanaan Adnan , Al-Anazi Hamoud , Al-Harbi Abdulaziz , Ginest Noel , Halim Abdul , Wilson Stuart , Johnston Bryan 
Published: November 2012

Abstract
Multistage stimulation of horizontal wells in tight gas carbonate formations in Saudi Arabia has been conducted since 2007. The production results from early completions showed significant improvements over conventional completion methods. As more wells were completed and more analyses conducted, it was observed that, although good fracture signatures were seen on the first fracturing stage, subsequent stages often showed no fracture signatures. Stage-by-stage testing confirmed that the greatest production came from the first stage and subsequent stages only added marginal contribution.
Initially, all of the horizontal wellbores in the RES formation carbonate reservoirs in which multistage fracturing (MSF) assemblies were deployed were drilled parallel to the direction of maximum or principal in-situ stress (σmax). This strategy was modified to drill wells parallel to the direction of minimum horizontal in-situ stress (σmin) to try to generate multiple transverse fractures. Since then, many wells drilled parallel to the σmin direction have been completed with MSF systems and fracturing treatments have been performed.
Drilling parallel to σmin is more challenging and requires careful consideration of mud weights to minimize formation breakout or breakdown. Likewise, deploying MSF systems in these wells is challenging since there are often fewer locations in which to place openhole packers due to potential borehole instability.
Presented in this paper are analyses of actual data from wells completed with MSF and hydraulically fractured. Unique fracture signatures confirmed that each stage was fractured, and subsequent production rates confirmed improved results. This paper will focus on the process of determining why it was necessary to change the drilling direction and how this strategy was implemented.
Maintenance Activity While the Wellhead Tower under Live Condition
Authors: Al Jabri A. 
Published: November 2012

Abstract
In response to the "Call for Proposal" for ADIPEC -2012, I'm pleased to submit a paper proposal for Managing Risk in Simultaneous Operations (SIMOPS) under Maintenance/Integrity/HSE/Operations Technical Categories for your consideration. Simultaneous Operation is defined as parallel operation of two or more activities e.g. drilling and production at the same time. Occurrence of this kind of operation exposes the parties to variety risks which due to their interaction. As a result parties before executing the activities meets and studies the mitigation factors taking into account ADMA-OPCO levels of safety.Considering a high production tower we utilize the full measures of SIMOPS. Nevertheless, this type of operation is not the case always for drilling. Maintenance campaigns were jobs under live conditions are executed, for that reason the oil tower needs to be shutdown and SIMOPS concept indeed essential to re-commission the tower.
Planning SIMOPS is time consuming due the measures needed to start such operation; the arrangements should contain F&G systems, Deluge system, production crew, panic bottoms on rig floor and the company representative beside other items. Finalizing the HSE audit takes more time. This measures delay the tower commission for a while accordingly losses in production occurs. Managing risks was excellent approach in making the SIMOPS operation much more efficient for our operation is profitable for the company I work for. The results were unprecedented indeed. We managed to shorten time of SIMOPS preparation, comply with the HSEQA regulation, reduce shutdown period of WHT accordingly gain more production, apply maintenance activities and reduce the time of the maintenance barge on-site. This technical paper will introduce our SIMOPS concept of managing risk during maintenance activities and present a case study of a similar case handled previously.
Feasibility Study of Miscible Gas Injection in a Carbonate Oil Reservoir; A Systematic Experimental and Simulation Approach
Authors: Kallehbasti Mehdi Alipour , Paroodbari Javad Rostami , Alizadeh Nasser , Ravari Reza Rostami , Amani Mahmood 
Published: November 2012

Abstract
Gas injection is a common practice in many carbonate oil fields; however, there is a lot of debate around the viability of economical enhanced oil recovery by miscible gas injection. For a correct simulation of miscible gas injection and monitoring the progress of the miscible front in the reservoir, a compositional reservoir simulation is needed. Fluid characterization is one of the most important parts of this simulation.
In this paper, fluid characterization for such a mechanism is discussed and a systematic approach is presented which could be used in any other similar study. The dynamic reservoir simulation is also brought at the end for comparison. The carbonate reservoir of the field of interest, contains 900 million barrels of under-saturated, 34 API degrees oil, with initial reservoir pressure of 8200 psi. After building a PVT model and adjusting the Equation of State (EOS), the Minimum Miscibility Pressure (MMP) of four different injection gases (N2, CO2, associated gas and sales gas) were calculated with different methods. Swelling test and slim tube test were also conducted which were used to cross check the EOS tuning. Although, MMPs in all cases were much lower than initial reservoir pressure, their effects on recovery factor were different. A compositional reservoir model was built based on the tuned EOS and the effects of all injection gases in different scenarios were examined. The procedures as well as the main results are explained in this paper.
LWD Resistivity Tool Application to Horizontal Geosteering in Thinly Bedded Carbonate Reservoir Layers
Authors: Obara Tomohiro , Yin Hezhu , Boyd Douglas , Yamamoto Kazuyuki 
Published: November 2012

Abstract
Logging While Drilling (LWD) propagation and azimuthal laterolog resistivity tools are utilized to accurately place long horizontal wells within a reservoir unit located near the base of a thick carbonate reservoir. The reservoir unit is comprised of a thin dolostone layer, sandwiched between two, moderately thicker limestone layers. The dolostone has higher resistivity than the two limestone layers. The degree of resistivity elevation varies laterally throughout the field depending on the degree of dolomitization, saturation and porosity levels. When adequate resistivity contrast between the limestones and dolostone exists, geosteering geologists utilize this contrast to direct the well in close proximity to or within the dolostone. This is the preferred method of geosteering in ZADCO for extended reach horizontals with its current drilling rig fleet, which are near their drilling reach capacity. This reduces the use of nuclear source porosity tools and the potential for long fishing operations should a stuck tool in hole incident occur. The history of the field development (e.g. water injection), simulation predictions of water front movement, geological characteristics, surveillance data and petrophysical data in the area of interest are checked to determine the suitability of resistivity tools (only) to geosteering.
Moving to New Technologies in Design Drafting and "As Building"
Authors: Krishnan Unni 
Published: November 2012

Abstract
Drawing is said to be the language of Engineers. In a simple drawing, we could depict what would require a thousand words to describe. No wonder why the technocrats always love to present their case with the aid of sketches and drawings.
In the olden days, technical concepts and ideas were transformed into paper using pencils and erasers and the media was tracing paper. It had the inherent disadvantage that pencil writings were getting smudged or erased with the passage of time and the tracing paper was getting torn or damaged. Gradually, the pencil leads gave way to ink; so also, the tracing paper was replaced with tracing films. Stencils with suitable size pens and drawing instruments like set squares, protractor, compass. French curve & dividers gradually became the order of the day. Drawing boards with fancy Tee squares started decorating the drafting offices. Quality improvements came to the fore, not just in presentation; but in productivity and storage of drawings.
During the Industrial Revolution, draftsmanship gradually became a specialized trade and drawing tables were considered an integral part of a Design or Engineering office. In those days, they were made of fine wood and brass; but slowly became more utilitarian and were built of steel and plastic.
Smart Well Technology in Daqing Oil Field
Authors: Xu Dekui , Zhong Fuwei , Wang Fengshan , Wang Jinyou , Li Yan , Xiaoyu Xu , Jiankun Zhou , Pan Weiguo , Xin Liu , Lin Zhongchao , Gan Lina 
Published: November 2012

Abstract
Daqing oilfield has entered the late period of extra high water production. With the development of horizontal well technology, coning of injected water is one of the most important production problems in the Daqing oilfield. The water cut of many wells in old depleted areas is more than 80%, and still rising. With the use of horizontal well technology in depleted areas, the problem will continue. An adjustable water system or smart well (intelligent completion) technology is urgently needed to solve the practical production problems in this oilfield.
This article first identifies the smart well (intelligent completion) technology, and the major companies using it. Secondly, the paper shows the development of smart well technology in China, the reason why we use smart well technology in the Daqing oilfield, the adjustable water cut system in the Daqing oilfield, and the application of smart well technology in the Daqing oilfield. Finally, a smart well is introduced, and some of advanced downhole devices and the prospects for their application in the Daqing oilfield are detailed.
Evaluation of Nonreactive Aqueous Spacer Fluids for Oil-based Mud Displacement in Open Hole Horizontal Wells
Authors: Osode Peter , Otaibi Msalli , Moqbil Khalid Bin , Kilani Khaled , Azizi Eddy 
Published: November 2012

Abstract
Reactive mud cake breaker fluids in long open hole horizontal wells located across high permeability sandstone reservoirs has had limited success because they often induce massive fluid losses. The fluid losses are controlled with special pills, polymers and brine or water, causing well impairment that is difficult to remove when oil-based mud (OBM) drill-in fluids (DIFs) are used. This situation has resulted in the drive for an alternative cleanup fluid system that is focused on preventing excessive fluid leak off, maximizing the OBM displacement efficiency and allowing partial dispersion of the mud cake for ease of its removal during initial well production. The two-stage spacer application is composed of a nonreactive fluid system, which includes a viscous pill with nonionic surfactants, gel pill, completion brine and a solvent.
Extensive laboratory evaluation was conducted at simulated reservoir conditions to evaluate the effectiveness of the OBM displacement fluid system. The study included dynamic high-pressure/high temperature (HP/HT) filter press tests and coreflood tests in addition to wettability alteration, interfacial tension and fluid compatibility tests.
The spacer fluid parameters were optimized based on wellbore fluid hydraulic simulation and laboratory test results, which indicated minimal fluid leak off and a low risk of emulsion formation damage. Three well trials were conducted in a major offshore field sandstone reservoir drilled with OBM. All three trial wells (one single and two dual laterals), which were treated, have demonstrated improvement in production performance. This paper will discuss in detail the spacer fluids optimization process, laboratory work conducted and the successful field treatments performed.
Innovative Process to Ensure Efficient Multiple Stage Fracturing Treatments
Authors: Hakami Ibrahim M. , Gomez Francisco A. , Asiri Khalid , Kharrat Wassim , Baez Fernando , Vejarano Eduardo , Ahmed Danish 
Published: November 2012

Abstract
Multiple-Stage-Fracturing (MSF) is a common practice today as it allows controlling the stimulation of long intervals, and improves the ultimate recovery of hydrocarbons. Multi-Stage-Frac-Completions (MSFC), designed with Open-Hole-Packers (OHP) and Frac-Ports (FP), are currently implemented by Saudi Aramco to perform such operations in gas wells. The integrity of the OHP and the functionality of the FP are vital for an effective fracturing treatment.
During a MSF treatment, the bottom FP is opened first by pressurizing the MSFC to a predetermined pressure. After pumping the first fracturing stage, a ball is dropped to isolate the lower zone, open the second FP with pressure, and enable the second fracturing stage. This step is repeated till all FP are opened and corresponding zones are fracced one after the other. In every step of pressurizing the MSFC, a drop in pressure is automatically interpreted by the assumption that the adequate FP is open and that the MSFC is ready for another fracturing stage. The OHP are also assumed to be holding without performing any downhole checks. Opening the wrong or multiple FP at the same time, having a leaking OHP will certainly lead to undesired results and possible expensive remedial rig interventions. Therefore downhole monitoring is needed to confirm that the MSFC is ready before every fracturing stage.
The Fiber-Optic-Enabled-Coiled-Tubing (FOECT) can be used as monitoring system by measuring the Distributed-Temperature-Survey (DTS), which is interpreted realtime to confirm which FP is open, and if OHP are sealing.
This paper demonstrates through two case studies how DTS was used to assess the readiness of the MSFC to proppant fracturing treatment. An innovative profiling process in MSFC is proposed to replace assumptions by measured facts, to give client confidence on when to start the fracturing treatment, and to eliminate unnecessary operation by detecting MSFC hardware malfunction.
An Advanced Special Core Analysis Study for a Middle Eastern Carbonate Field
Authors: Lun Lisa , Guice Kyle , Kralik Jim , Meissner Jon , Kenawy Maher , Kalam Zubair , al-Dayyni Taha 
Published: November 2012

Abstract
A novel special core analysis (SCAL) study was conducted utilizing samples from a Middle Eastern Carbonate Reservoir in order to gain insights into flow behavior across stylolitic intervals. This study included relative permeability and capillary pressure measurements performed on individual core plug and core plug composite samples, as well as a unique waterflood experiment on a four-inch diameter whole core composite. All laboratory flow measurements were performed at reservoir conditions of temperature, pressure, and net confining stress. As part of this study, it was demonstrated that wettability restoration remains a significant challenge for carbonate core samples, with implications for coring and core analysis program design and interpretation of historic SCAL data. Core-scale simulation using measured relative permeability and capillary pressure data along with whole core rock properties provides an opportunity to validate laboratory results across laboratory scales and can also serve as an intermediate to mechanistic modeling studies at larger scales. In this paper, the novel technical approach and significant findings for the special core analysis study are presented, with implications for modeling of displacement processes across stylolitic intervals in complex carbonate reservoirs. General recommendations for the design of special core analysis programs are also presented.
A New Method to Predict Performance of Gas Condensate Reservoirs
Authors: Al-Shawaf Ali , Kelkar Mohan , Sharifi Mohammed 
Published: November 2012

Abstract
Gas condensate reservoirs differ from dry gas reservoirs. Understanding of phase and fluid flow behavior relationships is essential if we want to make accurate engineering computations for gas condensate systems. Condensate dropout occurs in the reservoir as the pressure falls below the dew point, as a result of which, gas phase production decreases significantly.
The goal of this study is to understand the multiphase flow behavior in gas condensate reservoirs and, in particular, focusing on estimating gas condensate well deliverability. Our new method analytically generates inflow performance relationship (IPR) curves of gas condensate wells by incorporating the effect of condensate banking as the pressure near the wellbore drops below the dew point. The only information needed to generate the IPR is the rock relative permeability data and Constant Composition Expansion (CCE) experiment.
We have developed a concept of critical oil saturation near the wellbore by simulating both lean and rich condensate reservoirs and observed that the loss in productivity due to condensate accumulation can be closely tied to critical saturation. We are able to reasonably estimate re-evaporation of liquid accumulation by knowing the CCE data.
We validated our new method by comparing our analytical results with fine scale radial simulation model results. We demonstrated that our analytical tool can predict the IPR curve as a function of reservoir pressure. We also developed a method for generating an IPR curve by using field data and demonstrated its application by using field data. The method is easy to use and can be implemented quickly.