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Collaborating Authors
Nielsen, Frank Møller
Insights into the Mechanism of Lead Sulfide Pbs Fouling and The Influence of Light Distillate Fraction
Keogh, William (University of Leeds, Leeds) | Charpentier, Thibaut (University of Leeds, Leeds) | Eroini, Violette (University of Leeds, Leeds) | Olsen, John Helge (University of Leeds, Leeds) | Nielsen, Frank Møller (University of Leeds, Leeds) | Baraka-Lokmane, Salima (University of Leeds, Leeds) | Ellingsen, Jon Arne (University of Leeds, Leeds) | Bache, Oeystein (University of Leeds, Leeds) | Neville, Anne (University of Leeds, Leeds)
Abstract Deposition of inorganic scale on downhole completion equipment contributes to significant downtime and loss of production within the oil and gas industry. High temperature/high pressure (HT/HP) fields have reported build-up of lead sulfide (PbS) scale as a consequence of reservoir souring. This paper reports on the design of an experimental rig allowing diffusion of H2S into a scaling brine under dynamic environments. Multiphase conditions induced by introduction of a light distillate within the system were used to create an emulsion in order to reflect more accurately the scaling process occurring within sour systems. The results showed that the presence of an oil phase within the system caused the lead sulfide nano crystals to reside at the oil- water (o/w) interface; increasing surface build-up propensity through an adhesion process. Performance of a range of coatings for potential application in oilfield environments was determined through gravimetric measurements and microscopy techniques and the wettability of surfaces was shown to have a significant influence on the degree of lead sulfide deposition in a multiphase system.
- Energy > Oil & Gas > Upstream (1.00)
- Water & Waste Management > Water Management > Constituents > Salts/Sulphates/Scales (0.34)
Evaluation of Anti-Fouling Surfaces for Prevention of Lead Sulfide Scaling in Single and Multiphase Conditions
Keogh, William (University of Leeds) | Charpentier, Thibaut (University of Leeds) | Neville, Anne (University of Leeds) | O'Brien, Andrew (University of Leeds) | Eroini, Violette (Statoil ASA) | Olsen, John Helge (Statoil ASA) | Nielsen, Frank Møller (Statoil ASA) | Ellingsen, Jon Arne (ConocoPhillips) | Bache, Oeystein (ConocoPhillips) | Baraka-Lokmane, Salima (Total)
ABSTRACT Formation of mineral scale is one of the primary complications affecting production in the oil and gas industry. Soured reservoirs contain hydrogen sulfide (H2S) that can prompt the formation of exotic sulfide scales, leading to detrimental fouling that negatively affects the production of oil and gas. The mode of precipitation and deposition of lead sulfide (PbS) scale on a variety of anti-fouling surfaces for potential application in oilfield systems is examined in this paper. Previous sulfide scale work has reacted H2S derived from sodium sulfide (Na2S) with lead chloride (PbCl2) brine. However, the design of a rig for implementation of H2S gas into a reaction vessel resulted in a more accurate simulation of the processes occurring within sour reservoirs. Multiphase conditions induced by introduction of a light oil phase within a turbulent emulsion were used to simulate the presence of crude oil within a production line prone to sulfide scaling. The results showed that the presence of a light oil phase within the system caused the homogeneously-precipitated lead sulfide to reside at the interface between the oil and water phases, increasing its propensity to adhere to surfaces and promoting the dominant adhesion process. The wettability of anti-fouling surfaces had a significant bearing on the degree of lead sulfide deposition in a multiphase system. INTRODUCTION Though less common than carbonate and sulfate scales, build-up and deposition of metal sulfide scales on downhole equipment and production tubing can negatively affect the flow and production of oil . Lead and zinc sulfide scaling has become a concern in a number of North Sea oil and gas fields, rich in both hydrogen sulfide (H2S) gas and metal ions Sulfide ore deposits of lead and zinc, known as Mississippi Valley Type (MVT) deposits, are commonly observed in Devonian to Permian and Cretaceous to Tertiary formations . As a result, cations of lead and zinc are found naturally in many formation waters in HT/HP fields due to mineral dissolution of these ores over millions of years. Sulfide ions (S), formed when hydrogen sulfide (H2S) gas present in the reservoir reacts with formation water, are extremely susceptible to forming sulfide scales with dissolved metal cations . Injected water used for pressure support can also enrich seawater with heavy metal ions from the formation . Evolution of H2S gas or 'souring' of reservoirs in the North Sea can occur through both microbiological and geochemical means; as a consequence of the activity of sulfate reducing bacteria (SRB) and chemical reactions resulting from seawater injection, respectively . equation equation
- North America > United States (1.00)
- Europe > United Kingdom > North Sea (0.45)
- Europe > Norway > North Sea (0.45)
- (6 more...)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Inhibition and remediation of hydrates, scale, paraffin / wax and asphaltene (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
The Challenge of Squeezing a Water Sensitive HP/HT Reservoir - Lab and Field Experiences with a Novel Non Aqueous Inhibitor/Squeeze Enhancer Package
Chen, Ping (Champion Servo) | Hagen, Thomas (Champion Servo) | Bourne, Hugh (Champion Servo) | Turner, Katherine (Champion Servo) | Nielsen, Frank Møller (Statoil) | Rian, Mette (Statoil) | Haldoupis, Andreas (Statoil)
Abstract Down-hole scale control in Statoil's Åsgard field presents a particularly severe challenge. The field is producing from low permeability formations with a high draw down, through sub-sea templates. System pressure and temperature changes experienced during production promote the formation of carbonate scales, which have been identified in the near well bore area and perforated intervals. The high formation temperature and pressure, 165°C and 500 bars respectively, high chlorite content coupled to the water sensitive nature of some of the formations creates a challenging environment for downhole scale treatments. This paper will describe possible formation damage mechanisms that were identified for this water sensitive formation and the treatment strategy adopted to minimize them. It also presents the extensive laboratory studies that were undertaken to develop a non-damaging, non-aqueous inhibitor/squeeze enhancer formulation suitable for deployment under these harsh conditions. An understanding of the mechanisms by which the squeeze treatment package prevented water block formation and clay mobilization under such severe temperature and reservoir constraints, coupled to the mechanisms of squeeze life extension are discussed. The paper will also highlight the manufacturing challenges that were overcome to improve the environmental profiles of the products. The paper will finally discuss the two treatments, which have been performed to date with the non-aqueous products. Initial field data demonstrates that the application of this non-aqueous product package significantly reduced the potential for formation damage and allowed the successful treatment of these wells. Residual inhibitor returns remain significantly above MIC and a long squeeze life is expected for both wells. Introduction Oilfield scale is a water related problem and it is often associated with the production of produced water in the field once wells start cutting water. In the North Sea, typical scale problems are often related to the formation of BaSO4, SrSO4, CaSO4 and CaCO3. The severity of the problem and the most cost effective solution are highly dependent on the field operating conditions, which vary from mild to very severe scaling tendencies and from relatively simple low pressure, low temperature vertical platform wells to high temperature and pressure, complex subsea, multilateral and horizontal long reach completions. A number of remedial and proactive scale management tools are available including chemical and non-chemical based options. It is considered commonplace to prevent scale from forming in the system by injecting a chemical inhibitor continuously and/or by periodic squeeze treatments into the reservoir depending on the location of the scale deposition. Åsgard is within the Haltenbanken group consisting of Heidrun, Åsgard and Norne. The Haltenbanken area is environmentally sensitive due to its plentiful fish reserves and licensees are faced with stringent guidelines for the use of chemicals. The field lies on the Halten Bank, about 200 kilometres off mid Norway and is made up of the Smørbukk, Smørbukk Sør and Midgard Fields. Åsgard is considered to be among the world's largest sub-sea developments producing oil, condensate and gas through two production facilities, Åsgard A and B from ten reservoirs spreading over an area of 60Km by 20Km. The production facilities include 50 wells in 16 subsea templates tied together by 300Km of 10 and 20-inch flowlines. Carbonate scale deposition has been identified in the near well bore area and tubing for some of the wells in Åsgard.
- North America > United States > Texas > Permian Basin > Midland Basin > Wells Field (0.99)
- Europe > Norway > Norwegian Sea > Tilje Formation (0.99)
- Europe > Norway > Norwegian Sea > Halten Terrace > PL 479 > Block 6506/12 > Åsgard Field > Smørbukk Field > Åre Formation (0.99)
- (51 more...)