Oilfield Applications Research Articles

High-throughput corrosion quantification in varied microenvironments

Harsh conditions ranging from those of biomedical implants to industrial oilfield applications prompt rapid assessment of whether and to what extent corrosion will occur. Here, we describe and demonstrate a novel high-throughput approach to quantify corrosion susceptibility based upon electrical resistance and colorimetric outputs. We illustrate this capability by quantifying aerobic corrosion rates of steel alloys within hours, and by comparing anaerobic microbiologically influenced corrosion (MIC) conditions over several days. Such methods can be extended to rapidly assess conditions that will accelerate corrosion, to compare corrosion mitigation scenarios, and to explore biofilm formation and MIC mechanisms through robust replicate conditions.

Study on the Statics Analysis of Promoting the Drilling Efficiency of PDC Anchor Bit

PDC anchor bit has the very good rock fragmentation abilities with high penetration rate and long drilling time,which makes the drilling efficiency highly improved and the economic benefit remarkably increased.Now PDC anchor bit has been widely used in drilling field.But for the reason that it is sensitive to the formation characteristics and working conditions,it doesn’t achieve good performance in homogeneous formations such as conglomerate and interbeded sections.In order to reach the goal of enlarging the scope of PDC anchor bit application in oilfields,it is necessary to study the breakage mechanism in conglomerate formations and design the PDC anchor bit optimally.

Synthesis and performance of a polymeric scale inhibitor for oilfield application

A potential polymeric scale inhibitor used for oilfield was synthesized by solution polymerization. The static inhibition rate on calcium carbonate, calcium sulfate, barium sulfate, and strontium sulfate can reach up to more than 95 %. The inhibition performance of the polymer on calcium fluoride was also evaluated. Effects including test temperature, NaCl concentration, pH value, and evaluation time on the performance of the polymer were researched. Scanning electron microscopy and X-ray diffraction analyses were used to investigate the influence of the antiscalant on the scale crystal. The impact of carbon dioxide on the calcium carbonate crystal was also found. The inhibitor has a well-inhibition rate of more than 90 % in the actual oilfield water samples.

Surface Property Enhancement of UNS N07718 and G41400 by Ultrasonic Impact Treatment

Ultrasonic impact treatment is a relatively new surface modification process that may be potentially applied to impart compressive residual stresses onto oilfield parts experiencing wear, fatigue, and possibly environmentally-assisted cracking. Through severe plastic deformation, ultrasonic impact treatment is herein investigated to surface harden two oilfield alloys, UNS N07718, a premium alloy with satisfactory oilfield performance but occasionally lacking surface hardness and abrasive wear resistance, and UNS G41400, a comparatively low-cost alloy restricted by its corrosion fatigue limit in oilfield rotating equipment. For comparison purposes, the two studied alloys were ultrasonic impact treated under identical conditions and carefully selected to exhibit similar yield strengths (900 MPa). Results from microstructural examinations, micro-hardness indentations, and residual stress measurements all indicate that ultrasonically treated surfaces exhibit superior properties that create opportunities for implementing this new surface modification process in selected oilfield applications.

Experimental Study of Cucurbit[7]uril Derivatives Modified Acrylamide Polymer for Enhanced Oil Recovery

Acrylic acid cucurbit[7]uril ester (ACE) was prepared and utilized to react with acrylamide (AM) and hexadecyl dimethyl allyl ammonium chloride (C16DMAAC) to synthesize a novel AM copolymer (AM/ACE/C16DMAAC) through redox free-radical polymerization in aqueous solution. The chemical structure of AM/ACE/C16DMAAC was confirmed by Fourier transform IR and 1H NMR spectroscopies. Characterizations consisted of scanning electron microscopy, thermogravimetric analysis, and static light scattering, and the performance evaluations were conducted on several aspects such as intrinsic viscosity, stability, viscoelasticity, adsorption, and core-flooding experiments. Experiment results demonstrated the introduced ACE group could improve the salt tolerance and temperature resistance of polymer. Moreover, AM/ACE/C16DMAAC could significantly increase the oil recovery of 21.43%. The superior performances of AM/ACE/C16DMAAC revealed a potential application in high-temperature and high-mineralization oilfields for enhanced oil recovery.

Design of conductor soaking time in deepwater drilling

Abstract To decrease the risk in deep water drilling and shorten the drilling period, a conductor soaking time design method for deep-water jetting was provided and verified by oil field application. Based on the field simulation experiment of soil-pile interaction, the relationship between soaking time and bearing capacity was achieved, and a real-time bearing capacity calculation model of conductor was established. The mechanical properties of conductor in two conditions were analyzed, including Cam Activated Drilling Ahead (CADA) tool releasing stage and surface casing cementing stage, and the soaking time windows of the two stages were designed. Field application results show that: This method can ensure the safety in deep water drilling, optimize driving depth of conductor, and also improve the drilling efficiency. More than 12 hours per well on average in CADA tool releasing stage and 24 hours per well on average in surface casing cementing stage were saved.

Harsh environment sensors: Aircraft and oil field applications of electromagnetic and acoustic technologies

There is an old saying that what can be measured can be improved. However, measuring the key parameters in aircraft engines that drive efficiency and emissions is very difficult. This is even more the case in oil field applications, where extremely high pressures and temperatures are commonly encountered. But the benefits to society of reduced emissions (carbon, pollutants, and noise) and improved oil and gas recovery are tremendous. The task for instrument manufacturers is to develop sensors that are both reliable and cost effective. Recent advances in the application of electromagnetic and acoustic technologies are described for measuring temperature, pressure, flow, and composition in harsh environments. The sensors range from inductively and optically coupled ceramic and silicon devices to ultrasonic and SAW devices packaged with high temperature electronics to fiber optic systems. These sensors are now being deployed on new airframes, engines, deep water wells, horizontal tight shale formations, and high temperature/high pressure wells.

Weighing without Touching: Applying Electrical Capacitance Tomography to Mass Flowrate Measurement in Multiphase Flows

Electrical capacitance tomography has a well-established reputation as a research tool and has been used in a number of industrial applications including dry solids flows, gas–liquid flows, and wet gas flows. Electrical capacitance tomography can give detailed flow structure information that has been experimentally validated against other techniques. Here, we focus on its use for measuring the detailed flow structure and overall mass flowrate of dispersed dry solids in gravity-drop flows. Electrical capacitance tomography–based flowmeters capable of being mass-produced and deployed into the commercial industrial environment are being developed, and prototypes are available, but none are yet in full-scale manufacture. Sensors of this type are being designed for applications in milling, power generation, and pneumatic transport. The same sensor technology may also be applied to measurements of gas–liquid flows in oilfield applications.

The Preparation and Performances of Self-Dispersed Nanomicron Emulsified Wax Solid Lubricant Ewax for Drilling Fluids

An oil-in-water nanomicron wax emulsion with oil phase content 45 wt% was prepared by using the emulsifying method of surfactant-in-oil. The optimum prepared condition is 85°C, 20 min, and 5 wt% complex emulsifiers. Then the abovementioned nanomicron emulsifying wax was immersed into a special water-soluble polymer in a certain percentage by the semidry technology. At last, a solidified self-dispersed nanomicron emulsified wax named as Ewax, a kind of solid lubricant for water based drilling fluid, was obtained after dried in the special soluble polymer containing emulsifying wax in low temperature. It is shown that the adhesion coefficient reduced rate(ΔKf)is 73.5% and the extreme pressure (E-P) friction coefficient reduced rate(Δf)is 77.6% when the produced Ewax sample was added to fresh water based drilling fluid at dosage 1.0 wt%. In comparison with other normal similar liquid products, Ewax not only has better performances of lubrication, filtration loss control property, heat resistance, and tolerance to salt and is environmentally friendly, but also can solve the problems of freezing in the winter and poor storage stability of liquid wax emulsion in oilfield applications.

Preparation and Properties of Polymer/Vermiculite Hybrid Superabsorbent Reinforced by Fiber for Enhanced Oil Recovery

A series of polymer/clay hybrid superabsorbent composites (SACFs) comprising acrylamide, acrylic acid, sodium 2-acrylamido-tetradecyl sulfonate, fiber, and vermiculite byin situintercalation and exfoliated method was successfully synthesized. The structure of SACFs was characterized by IR, SXRD, and SEM measurements. Much notable absorbency for SACF-2 was observed compared to that for SACF-1 in the absence of hydrophobic group in the high cationic solution due to the alkyl carbon chain and sulfonic acid group of hydrophobic moistures protecting the cations from attacking the carboxylate groups. What is more, high temperature fiber which acts as bridge connection for the polymeric network structure enhanced both toughness and strength for SACF-4 in the harsh conditions. At the total dissolved substance of 212000 mg/L for Tarim Basin injected water and the temperature of 120°C, desired absorbency as well as water retaining property for SACF-4 was observed during the long period of thermal ageing. Core flooding experiments demonstrated that SACFs could migrate as amoeba in the porous medium and accumulated in the narrow channel to adjust injection profile, promoting the subsequent water diverting into the unswept zones. Finally, characteristic parameters for SACFs calculated from flooding experiment further confirmed these polymer/clay hybrid composites reinforced by fiber would have robust application in the mature oilfield for profile control.

Digital-Slickline Capability on Plug-and-Abandonment Conveyance Phases

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 23916, ’Impact of Digital-Slickline Capability on Slickline-Conveyance Phases of Plug-and-Abandonment Operations,’ by Stuart Murchie and Matthew Billingham, Schlumberger, and Douglas Guillot and Chuck Esponge, Production Wireline, prepared for the 2013 Offshore Technology Conference, Houston, 6-9 May. The paper has not been peer reviewed. Copyright 2013 Offshore Technology Conference. Reproduced by permission. Slicklines often play a vital role in offshore plug-and-abandonment (P&A) operations, either in those phases of the operation that require slickline conveyance or because logistical, footprint, operational, economical, environmental, or regulatory parameters of a P&A necessitate full reliance on this small, light, cost-effective conveyance offering. P&A activities using digital slickline increase equipment, logistic, and marine-support efficiency. Introduction Slickline-conveyance services have long been used in the exploration and production industry, with much of the slickline equipment, processes, and capabilities remaining relatively unchanged. Mechanical services have remained slickline’s mainstay. Evolutionary enhancements resulting from developments in metallurgical engineering are applied to the line itself and the mechanical tools deployed, along with improvements in pressure-control and winch technology used to deploy the tools and services safely in live wells. Oilfield application of battery-powered electronics in downhole tools began in the late 1970s, eventually including electronics-based devices such as gauges, firing heads, bottomhole-fluid samplers, and production-logging and caliper tools, as well as hydraulic tools. Slickline services were soon offered to both remedial services (pipe cutting, tubing punching, and perforating) and measurement services (production, pipe, and cement-bond-integrity logging). The demand for slickline services has remained steady over the years because of its many inherent advantages: minimal footprint; ease of logistics to, from, and on the wellsite; operational simplicity; and overall cost-effectiveness. The demand for hydrocarbons and the resulting effect on oil prices led to active developments in the subsea and deepwater arenas in past years, resulting in an increased complexity of well placements and associated well completions. This has led subsequently to new and innovative well-intervention capabilities being devised (and the associated equipment being engineered, developed, and deployed) as the need for intervention in these well types has grown. Cost management is also a key part of P&A operations, along with safe execution and quality outcomes. Enhancements to existing (and development of new) purpose-built vessels and equipment, coupled with an intervention workforce that is growing in relevant and multiskilled capabilities, are in high demand. Lightweight, low-footprint intervention systems can lower cost significantly if they can offer a broad range of services and can be deployed on lowercost vessels.

Salt- and temperature-stable quantum dot nanoparticles for porous media flow

The transport of colloidal nanoparticles (NPs) through porous media is a well-studied phenomenon at ambient temperature and in low-to-zero salinity water found in aquatic systems. Little is known at much higher temperatures and salinities such as conditions found in petroleum reservoirs, thus limiting the possible use of NPs in downhole oilfield applications. Using 3-nm CdSe quantum dots (QDs) as a model material, we report that NPs can be prepared with excellent colloidal stability at high ionic strengths and elevated temperatures. QDs with an outer coating of a nonionic ethoxylated alcohol surfactant showed little aggregation in synthetic seawater with ionic strength of 0.55M and 1M NaCl brine solution based on dynamic light scattering analysis. They showed colloidal stability up to 70°C, close to the cloud point temperature of the nonionic surfactant. They further showed nearly unimpeded flow behavior when carried in high-salinity water through a packed column of crushed calcite or sandstone mineral at room temperature. QDs were successfully passed through a medium-permeability Berea sandstone core (100mDa) at 17atm, 25°C, and 8mL/h. The preparation strategy for salt- and temperature-stable QDs is applicable to a wide range of particle sizes and compositions, toward the general handling and use of functional NPs in high-salinity environments.

Formation and characterization of thermal and electrical properties of CuO and ZnO nanofluids in xanthan gum

Nanotechnology provides promising possibilities for various oilfield applications in the upstream oil and gas industry. Nanofluids play a vital role in the development of newer technologies suitable for industrial applications and can be explored for use in the upstream petroleum industry. One of the commonly used biopolymers, xanthan gum (XG), is used in the upstream oil and gas industry as a rheological modifier, drilling fluid additive, emulsion stabilizer, and fluid loss controlling agent. Consequently, its use can be studied for the preparation of nanofluids, an application not reported in literature. In this study, zinc oxide (ZnO) and copper oxide (CuO) nanofluids, with varying concentrations of nanoparticles (0.1, 0.3, and 0.5wt.%), were prepared using the two-step method in a 0.4wt.% XG (as a dispersant) aqueous solution as a base. These CuO and ZnO nanofluids were characterized for stability and dispersion using a scanning electron microscope (SEM) and the dynamic light scattering (DLS) method, respectively. It is observed that the CuO nanofluid in XG aqueous solution is more stable than the ZnO nanofluid. XG was observed to form a jelly-like structure around the nanoparticles, keeping them suspended in the solution. This paper investigates and presents the thermal conductivity and electrical conductivity of these nanofluids. The results show that thermal and electrical conductivity are enhanced as the concentration of nanoparticles was increased. The thermal and electrical conductivity was observed to be enhanced by approximately 25 and 50% for ZnO and CuO nanofluid, respectively. This study is expected to form the basis for the development of nanofluid-based technologies with XG as the primary additive in the upstream oil and gas industry.

Synthesis of magnetic composite nanoparticles enveloped in copolymers specified for scale inhibition application

We report the synthesis of magnetic iron oxide nanoparticles encapsulated in maleic acid-2-acrylamido-2-methyl-1-propanesulfonate based polymer. This composite nanoparticle is specified for the high-pressure/high-temperature (HPHT) oilfield scale inhibition application. The process includes a facile-ultrasound-supported addition reaction to obtain iron oxide nanoparticles with surface coated by oleic acid. Then via inverse microemulsion polymerization with selected monomers, the specifically designed copolymers have been formatted in nanoscale. The structure and morphology of obtained materials were characterized by transmission electron microscopy (TEM), x-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and the thermal stability. The effectiveness of synthesized compounds as a carbonate scale inhibitor was investigated by testing method NACE standard TM 03-074-95 at aging temperature of 70, 90 and 120 °C. The magnetic nanocomposite particles can be easily collected and detected demonstrating their superior monitoring ability, which is absent in the case of conventional copolymer-based scale inhibitor.

Research into magnetic guidance technology for directional drilling in SAGD horizontal wells

SAGD horizontal wells are used to enhance oil recovery from heavy oil reservoirs. This technology requires precise separation between the production well and the injection well to ensure the efficient drainage of the reservoir. By studying the attitude of the downhole probe tube and the production well trajectory, an algorithm is proposed for eliminating ferromagnetic interference while drilling injection wells. A high accuracy filter circuit has been designed to correct the detected magnetic signals, which are ultra-weak, frequency-instable, and narrow-band. The directional drilling magnetic guidance system (DD-MGS) has been developed by integrating these advanced techniques. It contains a sub-system for the ranging calculation software, a magnetic source, a downhole probe tube and a sub-system for collecting & processing the detected signals. The DD-MGS has succeeded in oilfield applications. It can guide the directional drilling trajectory not only in the horizontal section but also in the build section of horizontal injection wells. This new technology has broad potential applications.

Q&A with Rod MacGregor, Chief Executive Officer and President, GlassPoint Solar

Q&A What is the main scope of the first thermal enhanced oil recovery (EOR) project in the Middle East and what are the technologies involved? Petroleum Development Oman (PDO), the largest producer of oil and gas in Oman, partnered with GlassPoint to build the Middle East’s first EOR project. GlassPoint’s Enclosed Trough technology was selected because of its protective glasshouse structure and streamlined oilfield integration. This technology takes proven concentrated solar power trough designs and pairs them with an agricultural glasshouse, making a system uniquely suited for desert oilfield applications. The 7 MW system is now in daily operation, generating an average of 50 tons of emissions-free steam per day that feeds directly into existing thermal EOR operations at PDO’s Amal West oil field. Was “cutting-edge technology” used in the development of the project? The Enclosed Trough architecture is an innovative approach to concentrated solar power. The system uses traditional agricultural glasshouses to protect solar collectors in a sealed environment, free of dust, dirt, sand, and humidity. By shielding the solar collectors from the elements, low-cost, lightweight materials can be used. The system generates steam by using ultra-lightweight curved mirrors. These aluminum mirrors move throughout the day, tracking the sun and focusing light on stationary receiver tubes. The high-intensity light heats the water in the receiver tubes to generate high-pressure steam for EOR. The maintenance of solar panels in the region is expensive because of the dust. How did you manage this problem? The technology’s architecture reduces maintenance cost by protecting the solar collectors from the harsh oilfield environment. We further reduce cost by using an automated robotic washing system, which eliminates the need for manual cleaning and minimizes water use, recapturing nearly 90% of the wash water. What are the major challenges you faced during the execution of the project? How did you manage them? Building anything in a remote desert location is a challenge. You must construct an entire work camp and bring all your materials in from a great distance. You cannot afford to forget a screwdriver, because it might cost you days of work. Extreme heat during the day means that workers are often building during twilight or dark conditions, when temperatures are less dangerous. We overcame these challenges by meticulously managing every detail of the building process. We designed our system to be easy to assemble, so it was a matter of being organized and making sure we had all the materials we needed on hand.

Optimal Antenna Configurations for Digital Oilfield Implementations

Antennas play a very pivotal role in the development and advancement of digital oil fields. They provide the last mile communication link to the field locations and thus must be properly sized to ensure the link availability and reliability. There are different types of antennas currently being deployed with each having different impacts on the communication link performance. This paper discusses typical antenna configurations for implementing last mile communications to the field in digital oilfield applications. It analyzes the characteristic of each configuration, the impact these different configurations have on data security, deployment speed and communication range and presents an optimal configuration that improves data security, deployment speed and communication range.

Feasibility Analysis of Fractured-Horizontal Well Development in HuaQing Ultra-Low Permeability Reservoir

Fractured-horizontal well can effectively reduce the percolation resistance near wellbore, improve the fluid mobility and enhance the production. However, in Chang 6 ultra-low permeability reservoir, BaiBao block, HuaQing oilfield, the efficiency of fractured-horizontal well is highly poor due to the production swiftly down and water cut sharply up. For studying the unsatisfying oil development by fractured-horizontal well in HuaQing oil field, the evaluation of reservoir properties and the option of stratum for fractured-horizontal well application have been performed based on the practical geological model of BaiBao block in HuaQing oil field. The numerical simulation is used to study the effect of reservoir permeability, Thickness and Aeolotropism on the production and to optimize the horizontal length, fracture spacing, half length and conductivity. The conclusion shows that Chang 63 stratum is qualified for fractured-horizontal well application. Through the practical geological model, the optimizations of horizontal length range, fracture spacing, half length and conductivity are 800m to 1200m, 77m, 150m, and 15μm2cm, respectively. The results can be conducted for fractured-horizontal well application in HuaQing oil field.

Stainless Steel Processing to Meet Advanced Applications

Stainless steel bar and wire products that cater to the high technology application in defence, nuclear, aerospace, oil field and chemical engineering is an area poised for rapid growth in India. The advancing capabilities of alloy steel plants in India have enabled mastering of techniques to make a wide variety of stainless steels. However, there are increasing challenges to meet the advanced property requirements, which call for a basic understanding on the structure property relationship that are influenced by appropriate alloy design and down-stream processing. The special steel industry cater to a wide variety of stainless steels namely ferritic, martensitic, austenitic and precipitation hardenable categories for meeting requirements of high technology. One of the process for making the primary stainless steels is Vacuum Oxygen Decarburisation process. For advanced applications, the primary melted steel is again secondary refined using electroslagremelting for the management of solidification structures and control of inclusions. In the austenitic grades, the hot forged and hot rolled heat treated steels, careful choice of chemistry controls the delta ferrite content and ensures uniformity of the grain size in the product during deformation processing and heat treatment. In the martensitic stainless steel grades, focus is given to delta ferrite, grain size control and appropriate tempering treatment. In the precipitation hardenable steels grades the aging reactions and hot deformation range have to be optimised for deriving specified mechanical properties. Special grades are produced using non ESR and ESR routes to meet high temperature applications such as turbine blades and bolting. In these grades control of delta ferrite content, carbides, carbo-nitrides in the matrix has a deep influence on the mechanical and sub zero fracture properties. In the ferritic stainless steel grade grain size control is critical. The presentation would bring forth the correlation between the alloy design, processing and properties that were achieved in the products mentioned above to meet some of the challenging requirements.

Multiphase flow pattern recognition in pipeline–riser system by statistical feature clustering of pressure fluctuations

In the offshore petroleum industry, it is important to recognize the severe slugging in multiphase flow patterns in oil and gas transportation through a pipeline–riser system. After analyzing the inadaptability of the existing methods, we proposed a simple and practical method of measuring the multiphase flow patterns based on pressure fluctuations. Our recognition was carried out in three steps. First, the outlet pressure signals were selected and processed because of their accessibility to practical applications in oil fields. Second, statistical and principal component analysis were performed on the sampled signals to obtain the clear interrelations between the signals and flow patterns and to extract useful features for forming flow pattern clusters for classification in the feature space. Finally, machine learning was applied to the clusters for constructing classifiers to predict the flow patterns automatically. The experimental results from a small-scale flow loop and an offshore petroleum field show that the proposed method is feasible and effective for recognizing the multiphase flow patterns in the pipeline–riser system.