High Pressure/High Temperature (HP/HT) Seals for Oil and Gas Production

1998 ◽  
Author(s):  
Thomas W. Ray
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Oil And Gas ◽  
Gas Production ◽  
Oil And Gas Production ◽  
High Pressure High Temperature

scholarly journals Corrosion Behavior of AISI 316L Stainless Steel Used as Inner Lining of Bimetallic Pipe in a Seawater Environment

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1539
Author(s):  
Daquan Li ◽  
Qingjian Liu ◽  
Wenlong Wang ◽  
Lei Jin ◽  
Huaping Xiao
Keyword(s):  
High Pressure ◽  
Stainless Steel ◽  
High Temperature ◽  
316L Stainless Steel ◽  
Oil And Gas ◽  
Gas Production ◽  
Atmospheric Conditions ◽  
Oil And Gas Production ◽  
Corrosion Rates ◽  
Seawater Environment

Seawater leakage commonly leads to corrosion in the inner lining of submarine bimetallic pipes, with significant financial implications for the offshore oil and gas production industry. This study aims to improve understanding of the performance of bimetallic pipes by investigating the corrosion behaviors of mechanically bonded 316L stainless steel. Immersion experiments were conducted in a seawater environment, under both atmospheric conditions and high temperature and high pressure conditions, and corroded surfaces were examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) to reveal micromorphology and elementary compositions. The results demonstrated that the corrosion rates of the bonded 316L specimen were between 5% and 20% higher than those of specimens without bonding under atmospheric conditions. This is attributed to the stress cracking that occurs during corrosion. Under high temperature and high pressure conditions, the corrosion rates were remarkably increased (91% to 135%) and the corrosion process took longer to reach equilibrium. This may be attributed, firstly, to the products becoming increasingly porous and weak, and also to the fluid stress caused by stirring in these experiments to simulate seawater movement.

scholarly journals Improvement of Thermodynamic Modeling of Calcium Carbonate and Calcium Sulfates at High Temperature and High Pressure in Mixed Electrolytes

2014 ◽  
Author(s):  
Zhaoyi Dai ◽  
Wei Shi ◽  
Amy T. Kan ◽  
Nan Zhang ◽  
Mason B. Tomson
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Oil And Gas ◽  
Equilibrium Constants ◽  
Virial Coefficients ◽  
Gas Production ◽  
Mixed Electrolytes ◽  
Oil And Gas Production ◽  
Mineral Solubility ◽  
Dependent Part

Abstract Deepwater oil and gas production plays a more important role in global energy support today in which high temperature and high pressure (HTHP) conditions usually occur. Mineral solubility predictions at HTHP with mixed electrolytes is thus getting more attention since it is critical for getting rid of scaling risks under such extreme conditions. In this study, Pitzer theory was applied to predict the solubility of gypsum, anhydrite and calcite over wide ranges of temperature, pressure, and ionic strength with mixed electrolytes. Solubility of gypsum was measured from 0 to 40 °C, from 14.7 to 20,000 psi, with 0 to 4 mol NaCl/kg H2O. Anhydrite solubility reported in literature was confirmed and adopted in this study. The equilibrium constants of gypsum and anhydrite are incorporated by the temperature dependent part reported in SOLMINEQ.88, and Atkinson and Mecik’s pressure dependent part. Based on these solubility data, equilibrium constants, and other virial coefficients, virial coefficients for Ca2+ and SO42- interactions with pressure dependence (i.e. βCaSo4(0), βCaSo4(2), CCaSo4(0)) are fitted over wide ranges of temperature and pressure (i.e. 0 to 250°C and 14.7 to 20000 psi). The solubility of gypsum/anhydrite can be precisely predicted based on the derived virial coefficients. More importantly, they can also be applied to accurately predict calcite solubility with mixed electrolytes from 0 to 250 °C (except for 100 °C) and up to 21000 psi. Based on the βCaSo4(2) values derived in the calcium sulfates system, the association constant of CaSO(0) at 14.7 psi and 25 °C matches very well with that reported in literature derived based on other methods.

Scale Prediction and Inhibition for Oil and Gas Production at High Temperature/High Pressure

SPE Journal ◽  
2012 ◽  
Vol 17 (02) ◽  
pp. 379-392 ◽  
Author(s):  
Chunfang Fan ◽  
Amy T. Kan ◽  
Ping Zhang ◽  
Haiping Lu ◽  
Sarah Work ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
High Temperatures ◽  
Oil And Gas ◽  
Gas Production ◽  
Scale Formation ◽  
Oil And Gas Production ◽  
Scale Inhibition ◽  
Kinetics Of ◽  
High Temperature High Pressure

Summary With the advance of new exploration and production technologies, oil and gas production has gone to deeper and tighter formations than ever before. These developments have also brought challenges in scale prediction and inhibition, such as the prevention of scale formation at high temperatures (150–200°C), pressures (1,000–1,500 bar), and total dissolved solids (TDS) (>300,000 mg/L) commonly experienced at these depths. This paper will discuss (1) the challenges of scale prediction at high temperatures, pressures, and TDS; (2) an efficient method to study the nucleation kinetics of scale formation and inhibition at these conditions; and (3) the kinetics of barite-crystal nucleation and precipitation in the presence of various scale inhibitors and the effectiveness of those inhibitors. In this study, nine scale inhibitors have been evaluated at 70–200°C to determine if they can successfully prevent barite precipitation. The results show that only a few inhibitors can effectively inhibit barite formation at 200°C. Although it is commonly believed that phosphonate scale inhibitors may not work for high-temperature inhibition applications, the results from this study suggest that barite-scale inhibition by phosphonate inhibitors was not impaired at 200°C under strictly anoxic condition in NaCl brine. However, phosphonate inhibitors can precipitate with Ca2+ at high temperatures and, hence, can reduce efficiency. In addition, the relationships of scale inhibition to types of inhibitors and temperature are explored in this study. This paper addresses the limits of the current predition of mineral solubility at high-temperature/high-pressure (HT/HP) conditions and sheds light on inhibitior selection for HT/HP application. The findings from this paper can be used as guidelines for applications in an HT/HP oilfield environment.

Laboratory-Scale Investigation of the Utilisation of Multiple Flat-Fan Nozzles in Descaling Petroleum Production Tubing

2021 ◽  
Author(s):  
Kabir Hasan Yar'Adua ◽  
Idoko Job John ◽  
Abubakar Jibril Abbas ◽  
Salihu M. Suleiman ◽  
Abdullahi A. Ahmadu ◽  
...  
Keyword(s):  
High Pressure ◽  
Oil And Gas ◽  
Gas Production ◽  
Oil And Gas Production ◽  
Scale Removal ◽  
Petroleum Production ◽  
Well Completion ◽  
Water Jets ◽  
Well Integrity ◽  
Injection Pressures

Abstract Despite the recent wide embrace of mechanical descaling approaches for cleaning scales in petroleum production tubings and similar conduits with the use of high-pressure (HP) water jets, the process is still associated with downhole backpressure and well integrity challenges. While the introduction of sterling beads to replace sand particles in the water recorded high successes in maintaining well completion integrity after scale removal in some recent applications of this technique, it is, unfortunately, still not without questions of environmental degradation. Furthermore, the single nozzle, solids-free, aerated jetting descaling technique – recently published widely – is categorized with low scale surface area of contact, low descaling efficiency and subsequent high descaling rig time. The modifications to mechanical descaling techniques proposed in this work involve the use of three high-pressure flat fan nozzles of varying nozzles arrangements, standoff distances and injection pressures to remove soft scale deposits in oil and gas production tubings and similar circular conduits. This experiment provides further insights into the removal of paraffin scales of various shapes at different descaling conditions of injection pressures, stand-off distances and nozzle arrangements with the use of freshwater. The results obtained from this study also show consistency with findings from earlier works on the same subject.

Ultrahigh-Temperature/Ultrahigh-Pressure Scale Control for Deepwater Oil and Gas Production

SPE Journal ◽  
2012 ◽  
Vol 17 (01) ◽  
pp. 177-186 ◽  
Author(s):  
C.. Fan ◽  
W.. Shi ◽  
P.. Zhang ◽  
H.. Lu ◽  
N.. Zhang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Oil And Gas ◽  
Gas Production ◽  
Ultrahigh Pressure ◽  
Flow Loop ◽  
Oil And Gas Production ◽  
Loop Method ◽  
Ultrahigh Temperature ◽  
Scale Control

Summary Scale control in deepwater oil and gas production is often challenging not only because of the geological and mechanical limitations associated with deepwater wells, but also because of the high-temperature (>150°C) and high-pressure (>10,000 psi) (HT/HP) environment, which may be associated with brine containing high total dissolved solids (TDSs) (>300,000 mg/L). These extreme conditions make scale prediction, control, and testing difficult because of the requirements for special alloys, pumps, and control equipment that are not readily available. Therefore, few reliable ultrahigh-temperature/ultrahigh-pressure (ultra-HT/HP) data are available. To overcome such challenges, an efficient flow-loop method has been established to study both the equilibrium and the kinetics of scale formation and inhibition at ultra-HT/HP conditions. This paper will discuss (1) an efficient flow-loop method to study the solubility of scale minerals at ultra-HT/HP conditions, (2) solubility of barite at temperature up to 200°C and pressure up to 20,000 psi, and (3) scale control and inhibitor selection for deepwater oil and gas production at ultra-HT/HP conditions. Specifically, the performance and thermal stability of some common scale inhibitors at the high-temperature conditions were studied in terms of barite-scale inhibition. The results to date indicated that (1) the solubility of barite at up to 200°C and 24,000 psi can be measured precisely by this newly developed flow-loop apparatus, (2) the rate of mineral scale formation at HT/HP may be considerably faster than previously projected from low-temperature studies and, hence, difficult to inhibit, (3) different scale inhibitors have shown considerably different thermal stability. The results and findings from these studies validate a new HT/HP apparatus for scale and inhibitor testing and information for better scale control at HT/HP conditions.

Stress Conversion Coefficients of Loads Crucial to Well Bore Safety

2012 ◽  
Vol 622-623 ◽  
pp. 1606-1610
Author(s):  
Bao Kui Gao ◽  
Xuan Zhuo Han ◽  
Hong Qiang Zhang
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Oil And Gas ◽  
Well Bore ◽  
Oil And Gas Development ◽  
Stress Increase ◽  
High Pressure High Temperature ◽  
Key Points ◽  
Conversion Coefficients ◽  
Cement Sheath

During oil and gas development, high pressure, high temperature and non-uniform earth stress increase the complexity of stresses in well bore which is composed of casing, cement sheath and formation. In order to obtain well bore stresses in hostile conditions, a new model is established with cement sheath and formation are treated as different materials. To predict well bore stresses rapidly, stress conversion coefficients are obtained that may change loads into stresses at key points conveniently.

Design of Sand Washing and Plug Removal Device with High Pressure Foam Fluid Jet

2012 ◽  
Vol 155-156 ◽  
pp. 722-725
Author(s):  
Wen Bin Cai ◽  
Guo Wei Qin ◽  
Yan He
Keyword(s):  
High Pressure ◽  
Oil And Gas ◽  
Horizontal Wells ◽  
Gas Production ◽  
Oil Field ◽  
Good Effect ◽  
Well Bore ◽  
Sand Production ◽  
Oil And Gas Production ◽  
And Performance

In the oil and gas production process, serious sand production causes reservoir and pipe blocked, which makes productivity declined, even stopped. It's the efficient means of sand washing and plug removal by using high-pressure foam fluid jet. The structure and performance of sand washing device determines the efficiency of sand washing and plug removal. The device's nozzle consists of anti-blocking valves, three kinds of nozzles with self-drive, rotation characteristics during the operation. The nozzles include sand washing nozzle, couple nozzle and power nozzle. This device can be used in horizontal wells with complex well bore situation to carry out sand and plug removal. The device has a good effect on sand washing and plug removal in the oil field.

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