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Splash and immersion zones on offshore installations are areas that are exposed to extremely aggressive environments due to the effects of sea water, tides, wind, waves, and/or ultraviolet radiation. Various certifications such as NORSOK(1) exist to help guide customers select a coating based on its corrosion resistance performance. Despite the necessity of these standards, it is helpful to understand that other properties such as substrate surface and cure conditions can greatly effect performance of the coatings. In this paper, we will compare adhesion of two coatings to different substrate surface conditions while both coatings will be cured in two different environments. Our goal is to investigate the effect of curing environment of coatings on adhesion to the substrate.
Various challenging environments exist where structures are exposed to continuous or periodic water immersion. This is often found in the offshore industries. Over the years, coatings have been developed to protect structures like pylons, walkways, and pipework that make up larger offshore structures including oil drill rigs and platforms.4 The coating must provide superior protection against corrosion and reduce the need for maintenance while addressing complex applications and providing minimal environmental impact.
Specifically considering the coating application, applicators are often subject to short timeframes and non-ideal environmental conditions. Coatings will often need to be applied on damp and wet substrates or submerged shortly after the coating is applied.4 Over the years, new coatings are being developed to meet these challenging requirements, providing better surface tolerance and underwater curing while maintaining protective and aesthetic properties. Coatings are typically made up of binder resin, pigment, filler, solvent (or water), and various additives for specific and unique coating properties. Historically, the coatings used to protect splash and tidal zones as well as immersion zones are comprised of epoxy amine resin. Once the coating is applied, the epoxy can form polar bonds with the substrate, allowing it to adhere to the substrate and cure underwater. Special attention should be given to the selection of the epoxy and amine resin for coatings cured under water that are subject to cathodic protection systems or other generated electrical currents. These electrical fields can disrupt coating adhesion when hydroxides are subsequently produced and can participate in electrophilic attack of the epoxide groups during cure.5 The choice of curing agent is also important. Amines are hygroscopic and may leach from the coating (amine blooming) or react with water and carbon dioxide to form a waxy or oily film mainly due to ammonium bicarbonate salts (amine blushing).6 Additionally, the polyamide/amine could separate and cause discoloration of the coating.7 Once the coating is cured, there is still potential for degradation due to water absorption into the coating from attraction to the polar groups on the epoxy resin, breaking hydrogen bonds, and swelling the polymer. Additionally, water could possibly degrade the resin by hydrolyzing epoxy ether linkages.8 Both the epoxy resin and amine curing agent should be carefully chosen to maintain durability and chemical and corrosion resistance while avoiding unwanted side reactions.
Willhite, J. (Applied Graphene Materials UK Ltd.) | Sharp, M. (Applied Graphene Materials UK Ltd.) | Chikosha, L. (Applied Graphene Materials UK Ltd.) | Weaver, W. (Applied Graphene Materials UK Ltd.)
Applied Graphene Materials UK Ltd. produces a number of graphene nanoplatelet (GNP) dispersions, enabling enhanced electrical/thermal conductivity, improved mechanical properties, and reduced water permeability/barrier properties within host systems. It has been demonstrated that GNPs, when incorporated into an organic coating, provide a highly tortuous pathway which acts to impede the movement of corrosive species towards the metal surface, rendering them highly beneficial in barrier coatings.
Current organic coating systems for C4/C5 environments (high and very high risk environmental categories) are typically comprised of a number of different coating layers, usually consisting of three layers, including a primer coat, an intermediate coat and a final topcoat. In this work we discuss the options available for GNP incorporation into full systems e.g. within the [zinc rich] primer, intermediate coat or top coat, including the merits and drawbacks associated with each approach.
We present our work on the incorporation of GNPs into the tiecoats of fully formulated C4/C5 systems (high and very high risk environmental categories), demonstrating clear anti-corrosion performance improvements using a combined neutral salt spray (NSS) and electrochemical AC impedance spectroscopy (EIS) test method.
Applied Graphene Materials UK Ltd. (AGM) produces a range of dispersions of graphene nanoplatelets (GNPs), enabling property introductions/enhancements such as electrical/thermal conductivity, mechanical e.g. fracture toughness, gas permeability and barrier type to be achieved. GNPs are manufactured using the company's patented proprietary "bottom up" process, yielding high specification graphene materials.
Coatings of various types such as inorganic1, organic2, hybrid3, nano4 and green5 have been widely employed in the corrosion protection of metallic materials under high and very high risk environmental categories for corrosion. Such categories, as referred to in BS EN ISO 12944-26, range from C4/C5 (high and very high risk environmental categories) with exterior examples of these categories including industrial and coastal areas of moderate to high salinity. Due to growth within the offshore industry in emerging economies and an increased rate of shipbuilding, the marine coatings market is estimated to be worth USD 15 billion by 20247.
Aljeaban, Norah (Saudi Aramco) | Alharbi, Bader (Saudi Aramco) | Balharth, Salem (Saudi Aramco) | Odewunmi, Nurudeen A. (King Fahd University of Petroleum and Minerals) | Mazumde, Mohammad A. Jafar (King Fahd University of Petroleum and Minerals) | Ali, Shaikh A. (King Fahd University of Petroleum and Minerals)
The application of corrosion inhibitors (CI) to producing oil and gas field systems is one of the most common practices of corrosion control. Acid stimulation fluids such as hydrochloric acid (HCl) and organic acids has high calcite and dolomite dissolving power; however, pumping HCl downhole during acid stimulation process particularly at elevated temperatures can cause severe corrosion. Therefore, the addition of corrosion inhibitors is indispensable to protect the metal from corrosion. More inhibitors that are efficacious are still needed to provide better protection against the corrosion. Two new bisquaternary ammonium salts; 1,4-Benzenedimethanaminium, N,N'-didodecyl-N,N,N',N'-tetramethyl-, dichloride (CI-1) and 1,4-Benzenedimethanaminium, N,N'-dihexadecyl-N,N,N',N'-tetramethyl-, dichloride (CI-2) as corrosion inhibitors were successfully synthesized, characterized and electrochemically evaluated for their corrosion inhibition efficiency in 1 M hydrochloric acid (HCl) solution on API 5L X60 low carbon steel. Potentiodynamic polarization measurement revealed mixed type inhibition mechanisms of the synthesized inhibitors. Inhibition efficiency of CI-1 increase with increase in concentration 2.0 to 20.0 ppm while CI-2 efficiency does not go beyond 2 ppm. Adsorption isotherm of CI-1 was found to deviate from Langmuir isotherm due to its interaction on low carbon steel and the interaction was approximated by Temkin isotherm. Analysis of the adsorption of CI-1 on API 5L X60 involve both physisorption and chemisorption.
Wang, Yefei (Key Laboratory of Unconventional Oil & Gas Development, China University of Petroleum East China, Ministry of Education, P. R. China, School of Petroleum Engineering, China University of Petroleum East China) | Yang, Zhen (Key Laboratory of Unconventional Oil & Gas Development, China University of Petroleum East China, Ministry of Education, P. R. China, School of Petroleum Engineering, China University of Petroleum East China) | Wang, Renzhuo (Key Laboratory of Unconventional Oil & Gas Development, China University of Petroleum East China, Ministry of Education, P. R. China, School of Petroleum Engineering, China University of Petroleum East China) | Chen, Wuhua (Key Laboratory of Unconventional Oil & Gas Development, China University of Petroleum East China, Ministry of Education, P. R. China, School of Petroleum Engineering, China University of Petroleum East China) | Ding, Mingchen (Key Laboratory of Unconventional Oil & Gas Development, China University of Petroleum East China, Ministry of Education, P. R. China, School of Petroleum Engineering, China University of Petroleum East China) | Zhan, Fengtao (College of Science, China University of Petroleum East China) | Hou, Baofeng (School of Petroleum Engineering, Yangtze University)
A novel indolizine derivative inhibitor for acidization was introduced. It could exhibit effective corrosion inhibition at a much lower concentration without propargyl alcohol and shows economic and environmental advantages. From quinoline, benzyl chloride, and chloroacetic acid, two indolizine derivatives were prepared under certain conditions. These inhibitive indolizine derivatives were both synthesised from benzyl quinoline chloride (BQC), which one of the conventional quaternary ammonium corrosion inhibitors used for acidising. The target compound was purified and instrumental analysis methods including elemental analysis, high-resolution mass spectrometry (HRMS), and NMR were used to characterise the chemical structure. The inhibition performance of the indolizine derivatives in 15 wt.% HCl, 20 wt.% HCl, and mud acid (12%HCl + 3%HF) for N80 steel was investigated by weight loss measurement, electrochemical method (potentiodynamic polarization and EIS), and SEM surface morphology assessment.
When 0.1 wt.% indolizine derivative was added, the inhibition efficiency of N80 steel in 15 wt.% HCl at 90 °C increased to 98.8 % and 99.1 % respectively without the synergistic effect of propargyl alcohol: however, in terms of BQC, even at a dosage of 1.0 wt.%, the inhibition efficiency of N80 steel only reached 83.3 % under the same conditions. The novel derivative could impart an improved corrosion resistance effect. Compared with BQC, there are more active adsorption sites in the derivative and therefore the inhibitor could be better fastened to the steel surface. The firmly adsorbed inhibitors would thereby prevent the metal surface from making contact with H+ ions and finally increase the inhibitory effect. As a high-efficiency corrosion inhibitor, the novel indolizine derivatives may offer a new strategy for corrosion protection in acidising.
The effectiveness of poly (2-acrylamido-2-methylpropane sulfonic acid) (PAMPS) and copolymers with acrylic acid (AA) and acrylamide (AM) magnetic nanogels as protective corrosion of CS in reaction with water by (EIS), (EFM) and tafel polarization method. Polarization method demonstrated that all the polymers are mixed inhibitor type. (EIS) Electrochemical impedance given that the attendance of these investigated polymers declines the double layer capacitance and improvement the charge transfer resistance. The polymers adsorption on surface of steel was follow isotherm Temkin. The morphology of the CS surface was examining by (EDX) energy dispersive X-ray and (SEM) scanning electron microscope. The data obtain showed improvement in efficiencies for inhibition with raising the dose of inhibitor.
CS is the common regularly utilized pipeline materials as a part of petroleum creation. In any case, it is exceptionally inclined to corrosion in environments include sulphur . Corrosion of sulfur has been one of the corrosion sorts in gas/oil manufacture, offering ascend to the pipelines failure and equipment's and utilized in biggest economic reduction and accidents. Likewise, spillage of raw petroleum because of endures consumption of pipelines would actuate fire accident, and natural contamination [2-4]. Explored to comprehend its mechanism, decrease the corrosion rate, additionally create experimental models to survey and foresee the parametric effects and the states-of the-art of internal corrosion of pipelines [5-12]. Theoretical approaches provide means of experimental of these reactions and there are many reports connection with this area . Last papers have study the connection between the efficiency and structure of the inhibitor molecule, but low attention has been paid to the reliance of the protection efficiency on the size and electronic distribution of the protective molecule, Relation between chemical structure and inhibition efficiency was not research, The super paramagnetic Fe3O4 nanoparticles covered with polymers are usually connected to the magnetic cores to ensure a strong magnetic . Attractive nanogels of regular interest are ferromagnetic magnetite (Fe3O4) covered with cross-connected polymer nanogels. The Fe3O4 center has solid attractive characteristic and super paramagnetic conduct, is of generally declines danger to the human body when epitomized in the defensive shell of polymer, which is cross-connected hydrogels polymer. The shell keeps the Fe3O4 center from total oxidation. In this appreciation, the utilizing of nanogels particles as a part of the field of consumption hindrance insurance for steel rather than ordinary natural inhibitors can deliver uniform flimsy film (with no pine opening because of cross-connected polymers) on the surface of CS to coat all surface with no deformities which give focal points over typical natural inhibitors. A few strategies have been produced to get ready attractive miniaturized scale and nanogels, for example, reverse microemulsion polymerization and emulsion polymerization [15-18]. The target of this paper is to calculation the inhibitive effect of these polymers on carbon steel in formation water by various electrochemical methods.
Nanotechnology involves scale, function, and composition that enable macroscopic properties with improved performance and high-value adding for any industry including the coatings industry. The large interest in graphene-based materials and other carbon-based polymorphs and nanomaterials are truly far-reaching. The industrial scale and possibility of applying these nanomaterials to advanced manufacturing and commercial applications have resulted in high throughput synthesis and lower costs. There is primary interest on their electrical and thermal conductivity properties. However, other applications are based on their ability to form very stable colloidal complexes. This talk will focus on the class of graphene (G) and graphene oxide (GO) nanomaterials that have been prepared with high loading in polymer matrices and ultrathin films to result in: anti-corrosion coatings and anti-microbial properties. We describe the preparation of very stable dispersions that can be used for coatings as well as anti-corrosion-superhydrophobic coatings. Interestingly, by preparation of nanoparticles that can be stabilized at dispersions, functional coatings can be prepared which have interesting uses in mitigating corrosion and killing bacteria. Colloidal particles that can be stabilized at liquid-liquid and air-liquid interfaces, functional Janus type nanoparticles can be prepared which have interesting uses in dispersants, rheological modifiers, and smart fluids. An important consideration is their use as anti-corrosion additives and the importance of nanostructuring.
Since the awarding of the Physics Nobel Prize in 2010, graphene, a two-dimensional carbon polymorph nanomaterial has continued to be the subject of much intense research. There has been interest worldwide for both fundamental properties and applications. Other carbon based polymorphs such as carbon nanotubes (CNT)s and fullerene - another Nobel Prize winning discovery followed much earlier are much more commercially available now. Elemental Carbon (C) naturally comes in two basic allotropes, namely graphite and diamond. These are two very different materials based on their chemical orbital hybridization and crystallinity despite being all carbon atoms. But as nanomaterials, they exhibit extraordinary electronic properties and are of primary interest to the materials community.1 There is a lot of interest now in utilizing them for future flexible electronic displays and devices. Graphene a, 2D nanomaterial has unusual electrical and optical properties (Figure 1). It is a single layer of carbon atoms arranged in an aromatic hexagonal lattice resulting in high mobilities and charge carrier generation. This arises of course from the delocalization and hybridization of pi-orbitals in a vast planar network of fused benzene like structures. It is an ideal monolayer coating material due to its impermeability, thermodynamic stability, transparency and flexibility. They exhibit high field effect mobility and can be formed through a number of chemical and physical methods and can be rendered useful in batch compounding. Its potential applications have encompassed a myriad of scientific and engineering disciplines such as high-performance nanocomposites, printed and flexible electronics, supercapacitors, chemical sensors, gas barriers and biomaterials. The latter include applications in gene and drug delivery, cancer treatment, cell growth control, stem cell differentiation, field effect transistor (FET) -based biosensors and as antimicrobial materials.
A low enthalpy geothermal system consisting of a water production and injection well faced serious injection obstruction problems within two-and-a-half months after start-up. The obstruction was so severe that the operation was suspended and research was done in order to determine the cause. To solve the obstruction problem the system was treated downhole using acid and biocide. During this treatment dangerous amounts of H2S were released. A study was initiated to understand the origin of the H2S and to give options for microbiological treatment and growth prevention. The results showed high amount of bacteria in the obstruction material indicating that microorganisms caused the obstruction. The detected species were typical thermophilic species with optimal growth temperature at 40-60 °C. During the 2,5 month period the casing was unprotected in high corrosive environment and bacteria and iron oxides, iron sulphides (FeS) and iron-copper sulphides (FeCuS2) were identified suspected to have caused the obstruction. The H2S formation was likely caused by a combination of biological FeS and CuFeS2 formation (due to Microbiologically Influenced Corrosion; MIC) and the release of H2S by the addition of acid during cleaning. To prevent this type of issues biocide treatment was applied, however, further investigation showed that microorganisms were still able to grow in the system. Identification of the microorganisms in the production water showed that several MIC related species are already present in the production water. Continuous monitoring and adjustment of kill strategies are essential for safe operation.
A geothermic system in the Netherlands faced serious injection obstruction problems two-and-a-half months after start-up. The obstruction was so severe that the operation was suspended and research was done in order to determine the cause. The conclusion was that the obstruction was caused by a combination of slime forming bacteria and iron and copper oxides/sulphides (possibly formed by bacteria). To solve the obstruction problem the system was treated downhole using acid and biocide. During this treatment dangerous amounts of H2S were released. The hypothesis is that H2S was formed by the activity of (sulphate reducing) bacteria and/or by the chemical reaction during the acid treatment. Due to QHSE (Quality, Health, Safety and Environment) regulations and lack of knowledge about what has happened in this system, there is the need to understand which processes have taken place and what can be expected in the future with regard to obstruction issues, H2S formation and Microbiologically Influenced Corrosion (MIC). To understand the issues better, the microbiology in the injection well was identified and interesting bacterial targets were further used to quantify its activity. To prevent microbiology related issue in the future, biocide was dosed once monthly in the injection well with the aim to prevent microbiological growth. However, after several months the injection pressure started increasing again slowly. Although the injection pressure was well within the production requirements, after more than two years of operation, additional tests were done and further research was performed to understand the reason for this increase in pressure and to get a better understanding and control of risks related to microbiology and MIC threat based on the detected microbiology. This report described the results of this study.
Yang, Zhen (China University of Petroleum) | Wang, Yefei (China University of Petroleum) | Zhan, Fengtao (China University of Petroleum) | Wang, Renzhuo (China University of Petroleum) | Chen, Wuhua (China University of Petroleum) | Ding, Mingchen (China University of Petroleum) | Hou, Baofeng (Yangtze University)
The novel indolizine derivative inhibitor for acidizing shows an effective corrosion inhibition without the synergism of propargyl alcohol. The inhibitive indolizine derivatives were generated from BQC (Benzyl Quinolinium Chloride, a commonly used key compound in acidizing inhibitor) via a moderate 1,3-dipolar cycloaddition mechanism. High Resolution Mass Spectrometry (HRMS) and NMR were used to confirm the detailed chemical structure. The inhibition of two indolizine derivatives in 15 wt.% HCl for N80 steel were studied by weight loss measurement and electrochemical analysis. Without the synergism of propargyl alcohol, the inhibition efficiency of N80 in 15 wt.% HCl at 90°C merely reaches 80.3% even when 1.0 wt.% of BQC was added. However, under the same conditions, when the dosage of two indolizine derivatives is only 0.1 wt.%, the inhibition efficiency significantly grows up to over 99.0 %. The indolizine derivative could display an excellent protection performance at a much lower concentration. Compared with BQC, the active adsorption sites in indolizine derivatives are enhanced and consequently the inhibition is increased. The indolizine derivatives exhibit an enlightening economic advantage and provide an eco-friendly inhibitive material. They might be applied as an important component of new acidizing inhibitor.
Corrosion of metal in acid medium brings not only the waste of resources but also environmental pollution in industrial production and oil field engineering. The use of various corrosion inhibitors is the most convenient and commercial method for reducing the attack of acid onto the raw metal materials.1-2 A variety of organic corrosion inhibitors which contains heteroatoms (N, O, P, S) and/or aromatic unsaturated functional moieties have been developed to retard the corrosion or damage of the metal equipment.3-5
In acidizing engineering, organic acids (such as acetic acid or formic acid) or inorganic acids (e.g. HCl or HCl/HF mixtures) are injected into the near-wellbore at high concentrations and corrosion inhibitors are critical because uninhibited acidizing treatment fluids would induce severe corrosion and damage.6-7 As a result, new effective inhibitors for acidizing are widely researched and always in great demand.8-9 Among the corrosion inhibitors, quaternary heterocyclic ammonium salts, which were usually synthesized by nitrogen-containing heterocyclic bases (pyridine, quinoline or their derivatives) and series of halogenated compounds, have been studied in detail due to their prefect anti-corrosion performance to prevent metal materials from getting corroded in acidizing.10-14 However, these quaternary heterocyclic ammonium salts usually would behavior well via the synergistic effect between the cation moieties of quaternary ammonium and propargyl alcohol, which is a poisonous but indispensable component in commercially available acidizing inhibitors.1,6 With the enhancement of the concept of environmental protection, the research on corrosion inhibitor calls for new type of inhibitors with low toxicity, pollution-free and high efficiency properties. Therefore, many “environmentally friendly” acidizing inhibitors with excellent inhibition performance are explored.15-17
Oluwabunmi, Kayode (University of North Texas) | Rizvi, Hussain (University of North Texas) | D'Souza, Nandika (University of North Texas) | Nazrazadani, Seifollah (University of North Texas) | Sanders, Steve (University of North Texas) | Hemmati, Vahid (University of North Texas) | Argade, Gaurav (University of North Texas)
The corrosion properties of PBAT/LDH coating on mild steel substrate was investigated. Tafel tests and electrochemical impedance spectroscopy tests (EIS) was used to analyze the corrosion resistance of the coating on the mild steel substrates. The morphological characteristics of the coatings was done using the scanning vibrating electrode technique (SVET) and environmental scanning electron microscopy (ESEM). Buffered saline solution containing NaCl-0.138 M, KCl-0.0027 M at room temperature and pH of 7.4 was used as electrolyte in the 3 corrosion tests. The tafel results showed that least corrosion current density value of 0.315 (μΑ/cm2) was recorded for 50 % LDH concentration in PBAT. This suggests that 50 % LDH in PBAT was about 98.5 % more corrosion efficient than 1018 bare mild steel and 0.7 % more that the 65 % concentration. The EIS results showed a similar trend. The 65 % LDH concentration showed about 25 % greater impedance to current flow over the 50 % LDH concentration in both the nyquist and bode plots. The SVET results revealed that the greatest corrosion protection of the mild steel substrates was observed with 50 % and 65 % LDH coating. This proved that an increased concentration of LDH in PBAT could potentially improve the corrosion resistance of mild steel when in service in a phosphate buffered saline environment.
Metallic materials used in the biomedical field are susceptible to localized corrosion especially pitting when they come in contact with body fluids and other solutions.1 The phenomenon of corrosion, a natural process that all metallic materials irrespective of the service environment suffer from have been examined using different techniques.2,3 Various forms of protective coatings have been used in the past to mitigate this effect.4 The use of organic coatings has recently gained more attention in the medical field as an environmentally friendly and economical technique for the corrosion protection for metals that come in contact regularly with body fluids. Surface coating of many products have to be carried out not only for aesthetic reasons, but specifically to maintain the integrity of the metallic substrate during their service life.5 Poly (butylene adipate-co-terephthalate) (PBAT) an aliphatic-aromatic biodegradable polyester primarily utilized in packaging industry;6,7 was investigated for its potential medical application.8 The non-cytotoxic behavior of the polymer using different cation exchange montmorillonites as filler at less than 10% by weight showed that through cytotoxicity tests, protein absorption analysis and total blood counts, PBAT composites are valuable in biomedical applications.9,10 Though, low hardness values and inherent non-conducting properties makes it suffers rapid delamination when used as a corrosion resistant coating, it was observed that it possessed the ability to enable platelet mobility which improved its mechanical properties with (less than 6%) of layered clay11,12. Based on this, we hypothesized that, reinforcing PBAT with LDH fillers a type of anion exchanged clays also known as hydrotalcite, with a brucite like structure; having a general formula [MII1-xMIIIx(OH)2x]x+(An”)x/n.mH2O, where Mn represents a divalent metal, Mra a trivalent metal, and An- an anion will help to increase the corrosion resistance of PBAT and give birth to a new set of bioinspired coatings suitable for use in medical implants.
ABSTRACTInhibitors have been used to mitigate corrosion in oil and gas producing assets. The efficiency of inhibitors are affected by several variables with the ability of an inhibitor to transport through the produced fluids onto the metal surface being one of the most important requirements. This can be achieved by formulating inhibitor products with a variety of chemistries that minimize their solubility in oil and are either soluble or dispersible in the brine.The partitioning of inhibitor products between the oil and aqueous phases require a reliable method to evaluate different inhibitor products. An analytical method using fluorescence spectroscopy has been developed as a means to measure inhibitor concentration. This new method offers several advantages over other commonly used techniques, such as dye transfer methods. The method offers a greater degree of accuracy, can be performed in the laboratory or at the well site, and individual analysis can be performed relatively quickly. Further, the performance of such formulations were evaluated under autoclave conditions in order to determine their applicability to existing producing systems.INTRODUCTIONCorrosion in metals is defined as the degradation of the materials' properties due to interactions with their environments1 and it has a significant impact on every stage of the oil and gas industry from production to transportation. In a study conducted from 1999 to 2001 by CC Technologies Laboratories, Inc., with support from the FHWA and NACE the total direct corrosion cost for the oil and gas exploration and production industry in the U.S. was estimated at 1.4 billion. The previous amount included expenses associated with surface pipeline and facilities, downhole tubing and capital expenditures related to corrosion.2 A recent report predicts this figure to be notably higher by 2015 due to the steady increase of direct and indirect costs of corrosion over the years, fueled by inflation and the expansion of oil and gas exploration and production.3