bluuebunny/crossref_metadata_2025 huggingface dataset:
PEMBUATAN KONSENTRAT ZAT WARNA ALAMI UNTUK BAHAN MAKANAN DARI DAUN PANDAN DAN BIJI KESUMBA BESERTA PENERAPANNYA
Authors: Paryanto Paryanto , Mastuti Endang
Published: November 2016

Abstract: Pandanus leaf and Bixa orellana linn seed can be used as natural colourant. This colourant has a beautiful colour effect and hardly to be imitated by synthetic colourant. Based on other study, natural colourant concentrate from these seed was tested into soaked food and dried foodl in order to increase food quality. In this study, we used Pandanus leaf and Bixa orellana linn seed with water as solvent in extraction process. Colourant and solvent was then separated by distillation.  Absorbancy and pH of product were then analysized. Absorbency analysis was conducted using pectrophotometer. Extraction of 1 kg of raw material and 5 L of water at 100oC in stirred tank for 30 minutes operation produced a thin colourant substance. Distillation of this substance at 100oC produced 300 mL of concentrated substance. We found that 1 kg of Pandanus leaf generate 60.66 grams of colourant substance and 1 kg of Bixa orellana linn seed generate 119.14 grams. Absorbancy analysis of product at 520 nm length of wave and pH 5-6 showed that concentration of product from Bixa orellana linn  seed is higher than product from Pandanus leaf. Products of liquid colourant substance were then tested into soaked and dried food such as Bolu Kukus cake, Klepon and Rengginang. Liquid colourant substance from Pandanus leaf gives brown and dark green colour with fragrance, whereas Bixa orellana linn seed gives dark yellow and dark red colour with distinctive smell.

 Keywords: natural colour, pandanus and bixa orellana linn, consentrate.
UJI KINERJA PADA PROSES PRODUKSI ETANOL MELALUI KOMBINASI PROSES FERMENTASI DAN STRIPPING
Authors: Margono Margono
Published: November 2016

Abstract: Renewable energy necesity have promote research on ethanol production technology. Ethanol is the potential renewable energy substituting gasoline. However, the conventional problem is high price of the ethanol. The objective of this research was to test the performance of alternative process in producing ethanol, i.e. combination of fermentation process with ethanol stripping in trickle bed bioreactor. The experimental was using Saccharomyces cerevisiae FNCC 3012 and sugarcane bagass as bed particle. It was devided into 2 process steps of biofilm development and ethanol production. Biofilm development was done by circulating medium in bioreactor aerobically. Duration of the biofilm development was 24 hours and followed by ethanol production step which was combinating anaerobic fermentation and stripping process using nitrogen. Production process was conducted for 36 hours lifetime. This method resulted biofilm developing in fermentation medium, not on baggas surfaces. Consequently, ethanol production happened in circulated fermentation medium. The productivity of this method of ethanol production process was not better than the conventional process. Neverherless, the experimental showed that the product stripping and fermentation could be done simultaneously. The stripping process increased ethanol product concentration up to 25% higher than in the broth.

 Keywords: ethanol, Saccharomyces cerevisiae FNCC 3012, trickle bed bioreactor, stripping, biofilm
PEMBUATAN ETANOL FUEL GRADE DALAM KOLOM UNGGUN TETAP DENGAN ADSORBENT HYBRID ACTIVE GRANULATED ZEOLITE – SILIKA GEL
Authors: Dyartanti Endah Retno
Published: November 2016

Abstract : Petroleum reserves in the world are dwindling, leading  to efforts to obtain renewable energy sources. Prospects of development of bioethanol industry in Indonesia is quite interesting, because Indonesia has a variety of natural resources that can be processed into bioethanol. Drying technology is currently used to produce ethanol fuel such as membranes, Pressure Swing Adsorption and vapor phase adsorption. Adsorption is a method that is simple and relatively inexpensive. This research aims at studying the characteristics of ethanol adsorption capacity by a mixture of zeolite and silica gel to the acquisition of ethanol concentration. The process of vapor phase adsorption of ethanol occurs in fixed bed column using a feed with a concentration of 93-95% ethanol. Ethanol fermentation first purified using a distillation process in the column packing material to get the concentration. Ethanol liquid feed is vaporized in the tank. Ethanol vapor then flowed into the fixed bed column containing a mixture of active zeolite and silica. Water vapor adsorbed by the adsorbent in the column stack of this bed. Ethanol vapor that not adsorbed is then condensed. Liquid ethanol results of the condensation process is fuel grade ethanol. The variables studied were weight ratio of zeolite-silica gel (g) (75:25; 50:50, and 25:75) and type in a structured or random piles. Sampling for analysis of ethanol levels done every 5 minutes for 30 minutes at a temperature of 12 ° C. The analysis was done by measuring the density of the solution condensation of the output of the column adsorber. In this research, obtained the highest ethanol content for this type of pile structured weight ratio zeolite: silica gel (g) respectively 75:25; 50:50, and 25:75 is the 99.2313% 99.5816%, and 99, 9582%. In a random pile of ethanol content obtained by 99.6363%, 98.3215% and 99.881%. The maximum ethanol content obtained on zeolite-silica gel ratio 25:75 for both structured and random mix. This is because the ratio of  Si/Al-silica gel is greater than the zeolite thus more effective in the adsorption of ethanol. And derived ethanol content in the stack is more stable than the unstructured random.

 Keywords: Adsorption, Zeolite Silica, Ethanol fuel grade

 
PENGARUH VARIASI KECEPATAN PUTAR DAN RATIO BAHAN PADA HIDROLISA TEPUNG KULIT SINGKONG
Authors: Mastuti Endang
Published: November 2016

Abstract: Generally, people make use of cassava bark to feed livestocks. Very often, they just throw it away as waste or rubbish.  In order to increase the economical value of it, the cassava bark is attempted to be alternative substance to create glucose through hydrolysis. This research is meant to uncover the effect of rotation speed and substance ratio at cassava bark flour hydrolysis towards the reducing glucose being produced, and hydrolysis reaction constant of cassava bark with acid chloride catalyst. The constant variable of this research is the cooking volume of 250 ml and the cooking temperature of 950C (boiling temperature). The observed variable is the rotation speed (100 rpm, 150 rpm, 200 rpm, and 250 rpm) and substance ratio (20 gr, 25 gr, 30 gr, and 35 gr. The sample of glucose is analysed using Lane-Eynon Method. The analysis of the data reveals that the more the rotation speed and substance ratio, the more glucose degree is produced. Moreover, the longer the reaction period, the higher the glucose degree is  produced. Maximum glucose production is gained at the operation condition of the speed rotation at 250 rpm and the substance ratio is 35 gram. In this research, in regard with orde one reaction, the constant of reaction speed at 0,0202 – 0,0243/minute and substance ratio variable at 0.023 – 0.052/minute is gained.

 Keywords: cassava bark; starch; hydrochloric acid; glucose
Destabilization and Treatment of Produced Water-Oil Emulsions Using Anionic Polyacrylamide with Electrolyate of Aluminum Sulphate and Ferrous Sulphate
Authors: Ma He , Sultan Abdullah S. , Shawabkeh Reyad , Nasser Mustafa S.
Published: November 2016

Surfactant and polymer flooding technology can greatly enhance the oil recovery through the expansion of sweeping and displacing efficiency. The recovered oil from surfactant and polymer flooding emulsifies the residual chemical, which makes the separation of water from oil quite difficult, yet the impact of the enhanced oil recovery (EOR) chemicals on the produced water cycle is generally neglected in chemically-based EOR studies. This includes compatibility of EOR chemicals with the additives used to pre-treat the injected water or change reservoir wettability and result in producing oil/water emulsion after EOR breakthrough.

The largest waste produced in oil and gas industries is believed to be the produced water, as it contains different sort of organic and inorganic admixture. There are a number of treatment methods available for produced water. To separate water from oil in a much efficient manner and to reach the emission standard, a new class of water soluble polymer of polyacrylamides (PAMs) with the addition of aluminum and ferrous sulphate were used as destabilizing agents for water/oil emulsions, which have been stabilized by surfactant (Tallowamine Acetate).

The impact of polyacrylamides with the addition of sulphates in turbidity reduction, COD, viscosity of volume separated water, and zeta potential were explored in this study. The effects of electrolytes such as aluminum sulphates and ferrous sulphate on produced water degree of flocculation in the existence of anionic polyacrylamide were investigated in terms of turbidity reduction and volume of separated water after jar test. Different concentrations of both sulphates added into optimum concentration polyacrylamide selected from jar test were utilized, and at optimum dosage, anionic AN 934 PAM with aluminum sulphate at its optimum concentration was proved as the best way to reduce the residual turbidity compared with other additives mentioned in this research. The results showed that the volume of separated water increased more than 25% compared when only PAMs were used, and the turbidity, viscosity, and COD reduction of separated water improved significantly. Addition of electrolytes such as aluminum sulphate and ferrous sulphate into polyacrylamide are both enhance the destabilization of water in oil emulsion in general compare to when only polyacrylamide used.
Formation Pressure Evaluation for Producing Wells Without Shutting Down the Well, Using Triple Spectral Noise Logging TSNL
Authors: Sarsekov Arlen , Al Neaimi Ahmed , Abed Abdulla , Saber Mohamed , Akram Fazeel , Aslanyan Arthur , Aslanyan Irina , Galin Nail , Makhiyanov Ruslan , Farakhova Rushana
Published: November 2016

Most oil and gas fields in the UAE are mature multi-layer carbonate reservoirs with vertical heterogeneity that complicates their development. Because of this heterogeneity, hydrodynamically isolated reservoir units tend to develop different formation pressures during production, which results in wellbore and behind-casing cross-flows reducing production performance. The conventional sub-layer formation pressure measurement method employs wireline formation testers (MDT) in some wells before putting them into production. Once a well is completed and put on stream, determining the sub-layer formation pressure becomes problematic, and the wellbore pressure recorded during SGS or PTA, being the only measurable parameter related to the weighted average pressure for all layers, cannot help to determine the pressure of each individual layer.

This paper describes a new method for formation pressure evaluation – Triple-rate Spectral Noise Logging (TSNL) – and presents case studies from an offshore carbonate field in the UAE.

The physics of this method is based on the fact that formation flow noise depends on the pressure drawdown and therefore contains information on formation pressure in each layer.

Once a spectral noise log is recorded across all layers at three flow rates and filtered of non-formation noise, formation pressure in each layer can be estimated through numerical pressure-noise simulations using the PolyGon software.

The key feature of the method is that it allows the measurement of formation pressure by layer in producing wells without deferring production. As a result, wells can be operated without early free gas release or water breakthrough, which prolongs their life and facilitates the future development of the field.

The determined layer formation pressure has been compared with MDT measurements from a newly drilled infill well. TSNL-based predictions of formation pressure for all layers turned out to be only several psi different from the MDT measurements. The SNL tool has outer diameter of 1 11/16 and can go through the most tubings. It allows TSNL to assess formation pressure behind the multiple metallic barriers - for example through tubing and two casings.

TSNL can greatly facilitate gas and water production management in cases of uneven depletion of multi-layer formations. It enables timely actions to be taken to shut off gas or water, which reduces the cost of conventional pressure measurements and prevents production deferment occurring during shut-in periods of pressure stabilisation for the conventional SGS and PTA surveys.
Digital Rock Analysis - Providing SCAL Properties for the Matrix of Tight Carbonates of the Najmah-Sargelu Formation, Kuwait
Authors: Mukherjee P. , SinghaRay D. , Golab A. , Al-Kandari J. , Quttainah R. B. , Arena A. , Mock A. , Curtis A. A.
Published: November 2016

The Najmah and Upper Sargelu formations in Kuwait are tight and unconventional fractured carbonate reservoirs that contain varying amounts of clay minerals and organic matter. Experimental MICP analysis revealed that almost all throats are smaller than 1μm in diameter and most are smaller than 100nm. The pores are poorly connected and this presents challenges for laboratory SCAL experiments. In view of this limitation, the exploitation of the reservoir had been severely constrained for want of parameters critical to reservoir simulation. The contribution of the tight matrix in controlling effective system conductivity needs to be understood to properly simulate production performance (Acharya et al., 2012). An integrated digital imaging and rock physics workflow was applied leading to data relating to fluid-to-fluid and matrix-to-fluid interactions for the matrix of this challenging reservoir. Through multi-scale digital rock analysis, petrophysical and multiphase flow properties were successfully derived for two samples from each of the Najmah and Upper Sargelu formations. These provide valuable input data to characterise the matrix of these complex unconventional carbonates.
Leveraging Intellectual Property to Enhance Collaboration and Technology Deployment While Mitigating Risks in the Partitioned Zone
Authors: Al-Suwailem Majed , Al-Mady Nasser
Published: November 2016

Saudi Arabian Chevron, Inc. (SAC) established a robust, evergreen Intellectual Property Program to manage its intellectual property assets across the onshore portioned zone. The program applies Chevron's intellectual property asset management system and accounts for government regulations and specific intellectual property provisions for company operations in the region.

Building on Chevron's information risk management principles, SAC intellectual property program has been deployed progressively in both Mina Saud (SAC Base) and Wafra Joint Operations. The number of patent applications in addition to the number and quality of external technical publications have improved significantly as a result of the program implementation in 2012. Since it was initiated, an increased appreciation of intellectual property rights by employees and contractors was realized as a result of the intellectual property training and awareness programs.

The paper describes the intellectual property program and how it has been customized to meet SAC strategic business requirements while creating mutual value and consensus internally and with different stakeholders.

This paper is intended to serve as a reference for strategic business units and small energy enterprises that are in the process of initiating, planning, executing, or monitoring their own intellectual property management programs.
Leveraging the Use of Real-Time Downhole Pressure Data, Pressure and Rate Transient Analyses to Enhance Reservoir Characterization and Expedite History Matching with Numerical Simulation
Authors: Naime R. Kansao , Yrigoyen A. , Haris Z. M. , Saputelli L. A.
Published: November 2016

Fast evaluation of reservoir performance is one of the main concerns for decision making. Additionally, lack of reservoir data is a big issue in performing numerical simulations and obtaining reasonable history matching results in a short period of time. Asset management tends to question and avoid cost and downtime related to data acquisition. Pressure and rate transient analyses (P&RTA), along extended periods of production, allows the characterization of reservoir and near wellbore features, however, P&RTA alone does not provide pressure and fluid distribution prediction beyond the wellbore, it requires the integration with reservoir simulation.

This paper provides a practical application for integrating well performance models to derive sandface pressure and rate data, that would enable P&RTA and ultimately a full-field integrated reservoir model. P&RTA facilitates the identification of reservoir parameters leading to improve and expedite reservoir history matching, and to perform the evaluation of various production scenarios. Available real-time pressure and rate data is key to achieving these objectives. The applied workflow allows engineers to quickly identify uncertainties and opportunities to evaluate different field development strategies to maximize the ultimate oil recovery.

The methodology was successfully applied in a reservoir study in South America. To achieve the goals, it was necessary to characterize the reservoir in terms of original oil in place, reservoir rock properties, compartmentalization and well performance history by well in each producing reservoir. Unstructured refined grid principles (Voronoi Grid) were applied to build a relatively small and simple model that considers all the required physics of the problem. The estimated reservoir properties from petrophysical analysis were validated against P&RTA thus honoring the near wellbore effects. The resulting model permitted the generation of key field development strategies considering additional well placement and completion technologies and best production operational practices, as well as the characterization of major uncertainties related with the reservoir-well system.

As a result of this application, prediction forecasts in comparison with the base case scenario for all formations showed that optimal production and development strategy results in 16.47 % reduction of water produced, with a simultaneous 13.2 % increase in overall oil recovery and 10 % project profitability. A series of recommendations were also derived including: (i) a data acquisition plan to minimize the impact of uncertainties in the field development plan, (ii) guidelines for generating a more reliable and economically profitable field development plan and (iii) opportunities visualization to improve and enhance oil recovery by conducting by water, gas and polymer injection.
Candidate Selection and Operation of Commingled Production with a Dual ESP System in a Green Field Development
Authors: Hoy M. , Florian T. , Geier H.
Published: November 2016

This paper presents the first application of a Dual Electrical Submersible Pump (ESP) system in an onshore well in OMV. It describes the whole process starting with the selection of the technology and candidate wells to the installation of the equipment and the start-up phase. Challenges in the operations as well as the methods for production allocation are addressed.

Commingled production was seen as a key approach for production acceleration in the development of a field with multiple-stacked reservoirs.

To proof this idea, a number of candidate wells and technologies were screened and the concept of "Dual ESP" was finally selected for a pilot in the well Erdpress 6. The design process required simulations and preparative selective production tests. Production allocation was crucial to evaluate the performance of the pilot; therefore several techniques were used, like fingerprinting based on chromatography and chloride content.

The Dual ESP system was a completely new approach in producing multiple targets in one well. The selective production tests proved to be essential for an optimum design of the ESPs. Two different methods were used to allocate the production rates to the respective intervals. The most significant finding was that results of the nodal analysis could be verified by chemical fingerprints. This also proved that the investment in downhole sensors was valuable. Interferences between the two pumps could be determined with the information of the sensors resulting in adjustments in the ESP settings. The conclusions from that pilot are that the application of the Dual ESP system is fulfilling the expectations from a technical point of view and that the information gathered prior to the design was crucial. However it is obvious that the application of this expensive technology has to be evaluated and justified in every technical and economical aspect. In the case of this pilot, an unexpected steep water cut rise impaired the forecasted profitability.

The use of the Dual ESP system was an exceptional approach to tackle the concept of commingled production. This paper covers the whole process from design to operation and shares the experiences and lessons learned to support future applications.
Comparing the effects of Breakers on a Long-Tail Sulfobetaine Viscoelastic Surfactant Solution for Well Stimulation
Authors: Fogang Lionel Talley , Sultan Abdullah S. , Kamal Muhammad Shahzad
Published: November 2016

Viscoelastic surfactants (VES) are viable alternative to polymer-based stimulation fluids due to potential risks of formation damage associated with polymer-based acid diverters. Internal breakers clean up VES-stimulated wells by reducing viscosity of the gel with much ease compared to polymer-stimulated wells. The objective of this work was to compare the effects of different breakers on a long-tail amphoteric VES solution for well stimulation. Solutions of a VES system (3.96 wt %) with erucamidopropyl hydroxypropyl sulfobetaine as the main surfactant reagent were prepared with varying concentrations of breakers and a fixed concentration of CaCl2 (6.2 wt %). The breakers used were Uthmaniya crude oil, n-decane and extra virgin olive oil. The concentration range of the breakers was 0.1-3 wt %. Rheology was used to determine the effect of these breakers. The samples were equilibrated for a week at 30°C and 60°C before testing at these temperatures. The VES solution showed three regimes of viscosity changes at both temperatures after the addition of n-decane within the tested breaker concentrations. The regime changes were in the following order: (i) the high viscosity regime (ii) the transition regime (iii) the low viscosity regime. Crude oil and olive oil induced only the high viscosity regime at 30°C, and the high viscosity and transition regimes at 60°C within the tested breaker concentration range. There was no low viscosity regime at both test temperatures after the addition of crude oil and olive oil within the tested breaker concentration range. Thus, n-decane was the most efficient breaker than crude oil and olive oil at both test temperatures. The work enhances the fundamental understanding of breaking mechanism at different temperature and for different types of oils. Low molecular weight oils such as n-decane are efficient breakers compared to high molecular weight oils. High molecular weight oils such as olive oil and crude oil are more efficient at high temperatures.
Characteristics of Fault Zones in Layered Carbonate Sequences, Onshore Abu Dhabi, UAE
Authors: Hijleh Yasmin Abu , Al-Hosani Sabah , Noufal Abdelwahab
Published: November 2016

The mechanical and kinematic properties as well as the structural architecture of fault zones are of great importance in structural geology, geomechanical modeling, and fluid flow studies. This paper emphasizes the structural/tectonic properties of the fault zones in the ADCO concession area. In general, fault zone properties are variable and are very hard to predict over short distances. It is impossible to extrapolate predictions of the structure of fault zones using seismic data alone given the resolution constrains. Therefore, this study serves as an attempt to incorporate and synthesize other data sources such as core and outcrop data to better characterize the fault zones of Abu Dhabi fields. In this study, data from available logs, cores, BHI (Borehole Images) and outcrop analogues were interpreted and integrated. Fault zone thickness variability has been observed in samples obtained from different faults of the same sequence and in samples collected at different positions along the same fault trace. The non-linearity of the fault zone thickness indicates the heterogeneous character of the fault zones, which in turn demonstrates the heterogeneity of the carbonate sequences. Fault zone permeability is also suggested to be as heterogeneous as the fault zone thickness. Interpretation carried out using outcrop data collected from Gebel Hafit and Ras Al Khaimah (United Arab Emirates) fault zones show that surface features such as natural drainages, changes in rock types, topography and other characteristics observed at the earth's surface are confined to fault zones. In the outcrops, fault gouge was affiliated with isoclinally folded and transposed bedding, rotated porphyroclasts and small-scale injection features that are attributed to ductile flow. In addition, the fault gouge displayed major thickness variations, which are also interpreted to be the products of ductile flow that occurred as a result of the slippage along fault planes. Within the fault zone, various geomorphic features are found that have their origin related to the lateral and vertical shuffling of fault-bounded slices and due to their presence near the master shearing fault. These features include offset, linear benches, aligned notches and saddles on spurs, scarps, fault-controlled drainage, and folds and pressure ridges. Understanding the mechanism in which fault- or shear-zone linkages' strength and microstructure evolve over fault deformation zones will ultimately lead to the development of more geologically realistic models of deformation that incorporate displacements which are concentrated in fault zones.
Experimental Study on the Effect of Spiral Flow on Wax Deposition Volume
Authors: Theyab Muhammad Ali , Diaz Pedro Antonio
Published: November 2016

One of the main flow assurance challenges in the oil industry is wax deposition. It can result in the restriction of crude oil flow in the pipeline, creating pressure abnormalities and causing an artificial blockage leading to a reduction in the production. Wax can precipitate as a solid phase on the pipe wall when its temperature drops below the Wax Appearance Temperature. The objective of this study is using spiral flow to mitigate wax deposition.

An experimental flow loop system was built in the lab to study the variation of wax deposition thickness under the single phase transport. A series of experiments were carried out at different flow rates (2.7 and 4.8 L/min) to study wax deposition and measure the wax thickness. The effect of factors on wax formation such as spiral flow, inlet coolant temperature, pressure drop, temperature drop, flow rates, time and shear stress have been examined.

The spiral flow created inside the pipe by inserting a twisted metal along the pipe, which will create high shear stress affecting to wax deposition. The results show that the wax inhibition percentage WI % by using the spiral flow at flow rate 2.7 L/min, inlet coolant temperature14 °C, was 65%. At flow rate 4.8 L/min, inlet coolant temperature 14 °C the wax inhibition percentage was 73%. Experimentally, it was found the spiral flow more efficient than the chemical inhibitors. The WI % increased, by merging the effect of the spiral flow and the inhibitor at flow rate 2.7 L/min, to 75, 92.2 and 100 % at inlet coolant temperatures 14, 24 and 33 °C, respectively. The WI % was increased by combining the influence of the spiral flow and the inhibitor to 4.8 L/min, to 83.5% at inlet coolant temperature 14 °C, 94.3% at 24 °C and to 100% at temperature 33 °C.

This percentage of inhibition will increased rapidly by increasing the inlet coolant temperature and decreased by reducing the inlet coolant temperature.

This technique of creating spiral flow inside the test section of the pipe will provide a step forward in flow assurance technology to mitigate the deposition of wax.
Completion Planning and Execution of the World's Longest ICD Partially Cemented Production System in an Offshore Horizontal Well
Authors: Aljubran M. J. , Looni Q. D. , Ramadhan A. A. , Neacsu M. , Mora C. T. , Emam A. A. , Alomoush J. , Ali A. M.
Published: November 2016

Under the current downturn in the oil and gas industry, the smart design and implementation of state-of-art drilling and completion technologies are key factors toward optimum return on investment. This serves toward authority for expenditure savings, maximum productivity index (PI), and effective operational strategy with minimum risks involved. As part of these efforts, Saudi Aramco successfully deployed the world's longest 4-1/2 in., partially cemented off-bottom liner with a sandstone production equalizer system in an offshore field in Saudi Arabia.

This record was achieved through close monitoring of the wellbore condition and accurate torque and drag simulation prior to the job. The 7,389 ft. open hole was horizontally drilled in a 6-1/8 in. section and carefully geosteered through the reservoir to yield a 90% net gross ratio (NGR). As soon as the target depth was reached, a reservoir model was built using the acquired petrophysical and reservoir data, and was employed for design optimization. A hydraulically-set, off-bottom liner system was utilized to spot the ICD screen completion across the desired zones in a single run. The completion liner was designed to provide the appropriate centralization and stiffness, and ensure reaching the borehole bottom.

It was challenging to place the well trajectory across the target layer which was just below a gas cap. A reservoir mapping was utilized to better understand the well placement relative to the gas cap. The sandstone production equalizer system and openhole packers were designed to divide the wellbore into sections and balance influx from high and low permeability zones. Restricting flow across the desired sections through introducing higher pressure drops serves into preventing early gas breakthrough from the overlaying gas cap.

This achievement was a result of the extensive engineering planning and close operational alertness during sidetracking and deployment. This paper will provide further details on the design and operation phases of this project.
The Impact of CO2 Injection for EOR & its Breakthrough on Corrosion and Integrity of New and Existing Facilities
Authors: Luqman Abdulla , Moosavi Ali
Published: November 2016

Carbon Dioxide (CO2) Injections for Enhanced Oil Recovery (EOR) is used to increase the amount of crude oil that can be extracted from reservoirs. The CO2 injected becomes miscible with the reservoir oil. The resulting miscible fluid has the favorable properties of lower viscosity, enhanced mobility and lower interfacial tension as compared to an oil reservoir without CO2. However, the produced oil through this EOR contains greater amounts of CO2 and with the re-injection of produced CO2 this breakthrough will increase over time.

This paper is based on Abu Dhabi Company for Onshore Petroleum Operations' (ADCO) experience with regards to CO2 EOR studies on asset integrity, material selection and corrosion mitigation. It serves as a guide to the main factors effecting CO2 corrosion, an assessment on what to look for in major equipment and the recommended material of construction and corrosion mitigation / control methods.

Dry CO2 is not corrosive, however when dissolved in an aqueous phase it will produce carbonic acid (H2CO3) which starts the corrosion process. Under ideal conditions Iron Carbonate (FeCO3) scales will form which act as a protective layer preventing further corrosion. As the CO2 increases this will increase the corrosion rate as no protective scale will be present.

Factors effecting CO2 corrosion and the FeCO3 protective scale are discussed; Water Wetting, Partial Pressure, Temperature, pH, Flow Regime & Velocity and Effect of H2S. In addition, a corrosion assessment highlighting areas of importance, material selection and mitigation methods is made on new and existing facilities; CO2 Injection Systems, Downhole Equipment, New Oil Producers and Existing Facilities.

Lack of free water will prevent any CO2 corrosion from occurring. This is especially important in the injection systems for transporting CO2 as, in the absence of free water, Carbon Steel can be used. Based on ADCO's experience, downhole completion material of non-sour CO2 injector wells should be Super 13 Chromium and for Oil Producers Carbon Steel with Corrosion Inhibition with Nickel Alloy for the tubing section under the packer.

For Oil Producers, this is subject to a case by case study. The use of Corrosion Resistant Alloys (CRA) or going with Carbon Steel with Corrosion Inhibition is the main dilemma. This is dependent on the dominating form of corrosion, formation of protective scales and the ability to maintain a stringent corrosion mitigation and monitoring regime.

Finally, for existing equipment, evaluation of the current condition of the equipment is important. This will guide the mitigations required. Some prevention methods include corrosion inhibition, neutralizing acidity of service and material upgrade to CRA. Type of method used should be based on company preference and life cycle cost analysis.

This paper serves as a guide to ADCO's experience for knowledge sharing and further development of ideas and innovations.
Accelerated Learning Curve Through Industry Collaboration: Case Studies from Large Tight Gas Project Executed in an International Marketplace
Authors: Riyami Qassim Al , Briner Andreas , Nadezhdin Sergey , Plus Packers , Gurmen Nihat , Kelkar Shrihari
Published: November 2016

A large, strategically important tight gas project in the Sultanate of Oman progressed over 5 years on an accelerated path from exploration to the development stage. Collaboration between operator and service provider helped advance the deployment of technology that made this acceleration possible. Poor initial success in both hydraulic fracturing treatment placement and hydrocarbon productivity along with limited resources with ever-expanding work scope were the main challenges faced in the first 2 years of exploration. To address these challenges, an integrated approach to the project was taken. Technology trials and the selective deployment of technology along with improved operations gave flexibility to this new efficiency model. Close collaboration with the service provider allowed smoother and faster progress. Collaboration included joint technology mapping exercises, team visits to North American locations of the operator and the service provider with the goal of knowledge sharing, faster technology transfer, and the secondment of a senior engineer from the service provider as a full-time production technologist to the operators' subsurface team. The effective execution of strategy and implementation of various technologies resulted in an increase in the success rate of fracture placement and zonal evaluation from the initially low 50% to 100%. The integration of several disciplines was critical to achieving this goal. Technologies deployed in the project comprised of rock and core mechanical tests, such as reservoir coring, openhole stress testing, sonic measurements, continuous unconfined compressive strength measurements, abrasive perforating, various fracturing treatment designs, and several geomechanical studies targeting different aspects of fracture initiation. An additional focus was on the assessment of fracture geometry using radioactive tracers, advanced sonic logging, geomechanical evaluation coupled with geological mapping, microseismic monitoring, and cutting-edge fracture design methodology in both vertical and horizontal wells. The collaborative efforts led to evaluation of similarities and differences between North American and international unconventional projects and suggested techniques and best practices that can be applied in the tight gas project in the Sultanate of Oman. This project has been deemed one of the first commercially successful gas deliveries in the Middle East from a tight gas reservoir. Technologies, methods, and strategies developed for this large tight gas project and tested in the field will contribute to improving the success rate on similar projects around the world.
Investigation of The Reliability of Hollow Glass Spheres as a Density Reduction Agent for Drilling Fluids under Physical Impact Forces Simulating Drilling Conditions
Authors: AlBahrani Hussain I. , Al-Yami A. S. , Amanullah M.
Published: November 2016

The use of hollow glass spheres (HGS) is emerging as a leading solution for reducing the density of drilling fluids. With the continuous depletion of reservoirs, the presence of naturally fractured formations, and high permeability formations, the need for low-density drilling fluids is greater than ever. Gases are commonly used to bring the density of water-based drilling fluids below that of water. HGS is an incompressible alternative that has proven to be capable of eliminating deployment complications of gases while achieving satisfactory results. There is a need to examine the behavior of HGS drilling fluids overtime under downhole drilling conditions that include high temperature (HT), high pressure (HP), and, most importantly, physical impact forces associated with the attrition effect of downhole tools and equipment.

The purpose of this study is to monitor the degradation and behavior of HGS drilling fluids while being subjected to conditions simulating a downhole drilling environment. A major part of the downhole environment is the physical impact forces resulting from the interaction of the drilling fluid with the circulation system components. A specially designed experiment was employed to investigate the crushing effect of the downhole drilling components on the glass spheres. As there are different pressure ratings of HGS available, the results of the experiment provide a measure of the reliability of HGS for specific operations.

The experimental procedure was designed with a focus on the Wasia formation considering that its pore pressure falls in the range 51-58 lb/ft3. Therefore, the HGS fluids were subjected to HPHT degradation periods in a hot rolling oven with the addition of a destructive element to the dynamic aging cell. The degradation period duration is approximated to be similar to that typically required for drilling through Wasia. The results showed that certain ratings of HGS can degrade significantly enough for the drilling fluid to gain up to 14 lb/ft3 in density. The magnitude of this failure in HGS means that selecting the wrong rating has the potential to put the well under substantial risk. The potential drilling troubles due to this failure include significant loss of circulation, formation damage, reduction in rate of penetration (ROP), aquifer water contamination, and stuck pipe.
Comparison Between The Mixed-In-Place Technology and Driven Piles as Offshore Foundations
Authors: Spagnoli G. , Scheller P.
Published: November 2016

In certain ground conditions, open-end driven piles are not a suitable foundation option. In calcareous sand, driven piles may cause particle breakage which leads to high levels of contraction and very low pile shaft capacities. The traditional alternative to driven piles is to employ a drilled-and-grouted pile system (D&G), which is however time consuming and expensive. The MIDOS (MIxed Drilled Offshore Steel) pile is a novel pile that utilizes the mixed-in-place (MIP) technology as an alternative to D&G piles. One of the key environmental advantages relative to driven piles is the reduced noise levels during installation. The following paper summarizes the in situ tests performed in quartz sand (with interbedded clayey layers) and laboratory tests on calcareous sands. Preliminary calculations were undertaken to assess the length required to support the design loading at ultimate capacity for a driven steel tube pile and an equivalent MIDOS pile. The results show that the MIDOS pile can provide significant savings in pile length when compared to a driven, open-ended steel pile with the same loads and ground conditions in silica sands and even more in calcareous sands.
Optimizing LNG Cooling Water System Performance-Biofouling Control Through Pulse-Chlorination®
Authors: Al Din Sabry Houssam , Venhuis Lars P.
Published: November 2016

Abu Dhabi Gas Liquefaction Company Ltd (ADGAS) owns and operates three LNG trains at DAS island. Trains 1 and 2 have common utilities while train 3 has a separate utilities system. The three LNG trains have a once-through sea cooling water (SCW) system which includes a series of heat-exchangers. The integrity and operational availability of these heat-exchangers is is vital for LNG facilities, and they operate most efficiently at an optimised water flow conditions which are required to prevent internal fouling, scaling, erosion corrosion and/or microbially induced corrosion (MIC).

To maintain the flow of seawater cooling system at the optimum parameters and to prevent blockage and corrosion due to micro and macro fouling (bivalves (oysters, mussels) and other marine organisms) the procedure at ADGAS is continuous injection of hypochlorite at the seawater intake of the trains. During the previous years, marine growth was however observed together with an increased fouling rate within the SCW system. Hence ADGAS initiated a review of the chlorination system and its efficiency. Sweco Nederland BV (SWNL) was contracted to perform a scouting survey for the seawater species at DAS island and a review on the existing chlorination system. For optimal control of biofouling, it was concluded the Pulse-Chlorination® technology (Bruijs, 2015) was feasible and recommended. During the second phase of this work, SWNL mobilised a laboratory on site at DAS Island for an optimization study on site. During this study, procedures are followed to monitor the target species behavioural response to a variety of hypochlorite dosing settings. Through a period of 6 weeks of experimentation the optimal Pulse-Chlorination dosage procedure was assessed. This Pulse-Chlorination procedure is an optimized intermittent dosing method that enhances a repetitive mode (on /off) of hypochlorite dosing, typically varying between 10 – 20 minutes. This procedure forces bivalves to continuous switch between metabolic mode (aerobic vs. anaerobic), whereby a physiological exhaustion of the bivalve is reached, resulting in a highly effective biofouling control. Through application of the Pulse-Chlorination dosing procedure an environment is created inside the SCW system in which larvae of fouling species will not settle and thus will not develop large fouling communities. Hereby settlement and growth of biofouling is prevented. In general, the advantages of Pulse-Chlorination are numerous. For ADGAS, the optimised chlorine dosing results in increased production due to the improved cooling water hydraulics, reduced operational risks, less consumption / production of hypochlorite (hence less ECP operation and maintenance expenditures) and more importantly less chlorine levels in the outfall, which is the largest benefit from an environmental point of view.
High-Profile Rigless Well Interventions with Coiled Tubing Tower
Authors: Gaidanov Robert , Burov Anton , Zhumagaliyev Yerlan , Elkurd Hani
Published: November 2016

Many wellbore recompletion and recommissioning operations requires a post-drilling well interventions without a drilling rig because a rig is either unavailable or uneconomical. Rigless operations are very relevant for the well interventions performed in one of the most challenging offshore development projects in the northern Caspian basin. These complex jobs are heavily impacted by extreme climate conditions, confined offshore installations, and strict safety regulations.

To overcome these challenges and to minimize operational risks, a rigless well intervention approach was selected with a specially designed multipurpose coiled cubing (CT) support tower that can perform a wide range of service operations with a unified well rigup. All the services can be kept under a single operational umbrella with a smaller crew, and a common base pattern erected around the well can be transferred to the next service line without major modifications.

Several innovative ideas were implemented to fulfill the offshore and operational requirements: A special base section of the tower with telescopic legs fits on the narrow working pad around the well and keeps permanent structures and service manifolds around the wellhead area intact.A specially designed CT tower skid system with a three-axes moving jacking frame on top includes a rotary table to allow the injector head to revolve into the required position.

This paper describes the success story of complex rigless well interventions using a newly designed multipurpose CT tower. The provided solution is proved to be more cost effective for the same applications as a drilling rig, and effectively reduced the necessary crew size and equipment footprint. This solution is designed for effective and safe operation in diverse environments, and can be customized to accommodate new solutions that would be and technologies developed in the future.
A Methodology for Multilateral Wells Optimization - Field Case Study
Authors: Cetkovic Ivan , Shammari Majed , Sager Talal
Published: November 2016

During the recent decades, a significant number of multi-laterals wells with smart completions controlled by different flow control technologies has been installed worldwide. This case study is based on a reservoir developed completely with multi-lateral wells. Each well is completed with three to seven laterals with different flow control technologies.

The study covers an analytical methodology and a multiphase flow model to optimize production that has multi-lateral wells equipped with flow control devices. Optimizing the complexity of this system, and understanding the contribution of each lateral during commingled production, has become a challenging process and is the main objective of this study.

A multi-lateral well modelling process was developed to obtain a representative model, which can predict accurate results under different operational conditions. The paper also covers a well test procedure, which is essential to guarantee the good quality of the data and ensure representative results.

This methodology covers two main factors affecting multi-lateral productivity, which are a flow dependent gas-oil ratio (GOR) rate and interference between the laterals.

The multilateral production optimization process was developed successfully to represent the operational conditions and optimize the well for different scenarios based on their specific reservoir management strategy. This model was extended successfully from a single to a multi-well model, including their actual surface facility network. The model will be considered in future production strategy plans.