Scale Control for Long Term Well and Facility Preservation

2021 ◽  
Author(s):  
Chao Yan ◽  
Wei Wang ◽  
Wei Wei

Abstract Oilfield scale and corrosion at oil and gas wells and topside facilities are well known problems. There are many studies towards the control and mitigation of scaling risk during production. However, there has been limited research conducted to investigate the effectiveness of scale control approaches for the preservation of wells and facility during a potential long term shut-in period, which could last more than 6 months. Due to low oil price and harsh economic environment, the need to shut-in wells and facilities can become necessary for operations. Understanding of scale control for a long term period is important to ensure both subsurface and surface production integrity during the shut-in period. The right strategy and treatment approaches in scale management will reduce reservoir and facility damage as well as the resulting cost for mitigation. In this paper, we will review and assess the scale risk for different scenarios for operation shut-in periods and utilize laboratory study to improve the understanding of long-term impact and identify appropriate mitigation strategy. Simulated brine compositions from both conventional and unconventional fields are tested. Commercially available scale inhibitors are used for testing. Various conditions including temperature (131-171 °F), saturation index (1.28-1.73), pH (7.04-8.03) and ratio of scaling ions are evaluated. The tested inhibitor dosage range was 0-300 mg/L. Inhibitor-brine incompatibility was also investigated. Sulfate and carbonate scales such as barium sulfate, strontium sulfate and calcium carbonate are studied as example. This paper will provide an important guidance for the management of well shut- in scenarios for the industry, for both conventional and unconventional fields. Performance of two scale inhibitors for same water composition are demonstrated. The efficiency of scale inhibitor #2 is lower than that of inhibitor #1. A linear correlation is observed for long term scale inhibitor performance in this case. Protection time is thus predicted from data collected from the first 8-week experiments. The predicted protection time at 250 mg/L of inhibitor A and B is 100 weeks and 16 weeks respectively. The actual protection time will be compared to the predicted value. The inhibitor-rock interaction has also been preliminarily studied. The effects of inhibitor adsorption onto formation rock should be considered for chemical treatment design and performance/dosage optimization. This study provides novel information of scale control in a much longer time frame (up to 6 months). Various parameters may have effects on their long term control. Results will benefit the chemical selection and evaluation for long term well shut-in scenario. In addition, brine-inhibitor compatibility is evaluated simultaneously.

SPE Journal ◽  
2021 ◽  
pp. 1-14
Author(s):  
Yue Zhao ◽  
Zhaoyi Dai ◽  
Chong Dai ◽  
Xin Wang ◽  
Samridhdi Paudyal ◽  
...  

Summary Scale inhibitors have been widely used as one of the most efficient methods for sulfate-scale control. To accurately predict the required minimum inhibitor concentration (MIC), we have previously developed several crystallization and inhibition models for pure sulfate scales, including barite, celestite, and gypsum. However, disregarding the wide existence of barium-strontium-sulfate (Ba-Sr-SO4) solid solution in the oil field, no related models have been developed that would lead to large errors in MIC determination. In this study, the induction time of Ba-Sr-SO4 solid solution was measured by laser apparatus with or without different concentrations of scale inhibitor diethylenetriamine penta(methylene phosphonic acid) (DTPMP) at the conditions of barite saturation index (SI) from 1.5 to 1.8, temperature (T) from 40 to 70°C, and [Sr2+]/[Ba2+] ratios from 0 to 15 with celestite SI < 0. The results showed that the Ba-Sr-SO4 solid solution’s induction time increases with the [Sr2+]/[Ba2+] ratio at a fixed barite SI, T, and DTPMP dosage. That means the MIC will be overestimated if it is calculated by the previous semiempirical pure barite crystallization and inhibition models without considering the presence of Sr2+. To resolve such deviations, the novel quantitative Ba-Sr-SO4 solid solution crystallization and inhibition models were developed for the first time. The novel models are in good agreement with the experimental data. They can be used to predict the induction time and MIC more accurately at these common Ba2+ and Sr2+ coexisting scenarios. The observations and new models proposed in this study will significantly improve the barite scale management while Ba2+ and Sr2+ coexist in the oil field. NOTE: Supplementary materials are available in support of this paper and have been published online under Supplementary Data at https://doi.org/10.2118/205367-PA.


RSC Advances ◽  
2016 ◽  
Vol 6 (7) ◽  
pp. 5259-5269 ◽  
Author(s):  
Ping Zhang ◽  
Amy T. Kan ◽  
Mason B. Tomson

Prepared crystalline Si–Ca–DTPMP scale inhibitor nanomaterials with enhanced transportability and extended squeeze lifetime potentially for oilfield mineral scale control.


Author(s):  
Adnan Khalaf i Hammed Al-Badrani ◽  
Hind Ziyad Nafeih

The Belt and Road Initiative is an initiative to revive the ancient Silk Road, through networks of land and sea roads, oil and gas pipelines, electric power lines, the Internet and airports, to create a model of regional and international cooperation.       It is essentially a long-term development strategy, launched by the Chinese president in 2013 to become the main engine of Chinese domestic policy and foreign diplomacy and within the framework of the soft power strategy, to enhance its position and influence in the world as a peaceful and responsible country.   The study includes identifying the initiative and setting goals for China, as well as the challenges and difficulties that hinder the initiative.


2020 ◽  
Vol 26 (1) ◽  
pp. 35-45 ◽  
Author(s):  
A. G. Kazanin

The modern oil and gas industry is heavily dependent on the processes and trends driven by the accelerating digitalization of the economy. Thus, the digitalization of the oil and gas sector has become Russia’s top priority, which involves a technological and structural transformation of all production processes and stages.Aim. The presented study aims to identify the major trends and prospects of development of the Russian oil and gas sector in the context of its digitalization and formation of the digital economy.Tasks. The authors analyze the major trends in the development of the oil and gas industry at a global scale and in Russia with allowance for the prospects of accelerated exploration of the Arctic; determine the best practices of implementation of digital technologies by oil and gas companies as well as the prospects and obstacles for the subsequent transfer of digital technologies to the Russian oil and gas industry.Methods. This study uses general scientific methods, such as analysis, synthesis, and scientific generalization.Results. Arctic hydrocarbons will become increasingly important to Russia in the long term, and their exploration and production will require the implementation of innovative technologies. Priority directions for the development of many oil and gas producers will include active application of digital technologies as a whole (different types of robots that could replace people in performing complex procedures), processing and analysis of big data using artificial intelligence to optimize processes, particularly in the field of exploration and production, processing and transportation. Digitalization of the oil and gas sector is a powerful factor in the improvement of the efficiency of the Russian economy. However, Russian companies are notably lagging behind in this field of innovative development and there are problems and high risks that need to be overcome to realize its potential for business and society.Conclusions. Given the strategic importance of the oil and gas industry for Russia, its sustainable development and national security, it is recommendable to focus on the development and implementation of digital technologies. This is crucial for the digitalization of long-term projection and strategic planning, assessment of the role and place of Russia and its largest energy companies in the global market with allowance for a maximum number of different internal and external factors.


GPS Solutions ◽  
2021 ◽  
Vol 25 (3) ◽  
Author(s):  
Damon Van Buren ◽  
Penina Axelrad ◽  
Scott Palo

AbstractWe describe our investigation into the performance of low-power heterogeneous timing systems for small satellites, using real GPS observables from the GRACE Follow-On mission. Small satellites have become capable platforms for a wide range of commercial, scientific and defense missions, but they are still unable to meet the needs of missions that require precise timing, on the order of a few nanoseconds. Improved low-power onboard clocks would make small satellites a viable option for even more missions, enabling radio aperture interferometry, improved radio occultation measurements, high altitude GPS navigation, and GPS augmentation missions, among others. One approach for providing improved small satellite timekeeping is to combine a heterogeneous group of oscillators, each of which provides the best stability over a different time frame. A hardware architecture that uses a single-crystal oscillator, one or more Chip Scale Atomic Clocks (CSACs) and the reference time from a GPS receiver is presented. The clocks each contribute stability over a subset of timeframes, resulting in excellent overall system stability for timeframes ranging from less than a second to several days. A Kalman filter is used to estimate the long-term errors of the CSACs based on the CSAC-GPS time difference, and the improved CSAC time is used to discipline the crystal oscillator, which provides the high-stability reference clock for the small satellite. Simulations using GRACE-FO observations show time error standard deviations for the system range from 2.3 ns down to 1.3 ns for the clock system, depending on how many CSACs are used. The results provide insight into the timing performance which could be achieved on small LEO spacecraft by a low power timing system.


2007 ◽  
Vol 12 (1) ◽  
pp. 37-62 ◽  
Author(s):  
Paul Lambert ◽  
Kenneth Prandy ◽  
Wendy Bottero

This paper discusses long term trends in patterns of intergenerational social mobility in Britain. We argue that there is convincing empirical evidence of a small but steady linear trend towards increasing social mobility throughout the period 1800-2004. Our conclusions are based upon the construction and analysis of an extended micro-social dataset, which combines records from an historical genealogical study, with responses from 31 sample surveys conducted over the period 1963-2004. There has been much previous study of trends in social mobility, and little consensus on their nature. We argue that this dissension partly results from the very slow pace of change in mobility rates, which makes the time-frame of any comparison crucial, and raises important methodological questions about how long-term change in mobility is best measured. We highlight three methodological difficulties which arise when trying to draw conclusions over mobility trends - concerning the extent of controls for life course effects; the quality of data resources; and the measurement of stratification positions. After constructing a longitudinal dataset which attempts to confront these difficulties, our analyses provide robust evidence which challenges hitherto more popular, politicised claims of declining or unchanging mobility. By contrast, our findings suggest that Britain has moved, and continues to move, steadily towards increasing equality in the relationship between occupational attainment and parental background.


Significance Although a ceasefire has been in place since October 2020, very little has been done during that time to integrate or demobilise the many armed forces and groups that exist across the country. The obstacles are formidable. Impacts Significant demobilisation and reintegration will not happen in the near term. Local security will continue to rest on fragile political and financial arrangements between armed groups and governing authorities. The current high levels of oil and gas revenue will tend to discourage unrest.


2021 ◽  
Author(s):  
Andrés Martínez

<p><strong>A METHODOLOGY FOR OPTIMIZING MODELING CONFIGURATION IN THE NUMERICAL MODELING OF OIL CONCENTRATIONS IN UNDERWATER BLOWOUTS: A NORTH SEA CASE STUDY</strong></p><p>Andrés Martínez<sup>a,*</sup>, Ana J. Abascal<sup>a</sup>, Andrés García<sup>a</sup>, Beatriz Pérez-Díaz<sup>a</sup>, Germán Aragón<sup>a</sup>, Raúl Medina<sup>a</sup></p><p><sup>a</sup>IHCantabria - Instituto de Hidráulica Ambiental de la Universidad de Cantabria, Avda. Isabel Torres, 15, 39011 Santander, Spain</p><p><sup>* </sup>Corresponding author: [email protected]</p><p>Underwater oil and gas blowouts are not easy to repair. It may take months before the well is finally capped, releasing large amounts of oil into the marine environment. In addition, persistent oils (crude oil, fuel oil, etc.) break up and dissipate slowly, so they often reach the shore before the cleanup is completed, affecting vasts extension of seas-oceans, just as posing a major threat to marine organisms.</p><p>On account of the above, numerical modeling of underwater blowouts demands great computing power. High-resolution, long-term data bases of wind-ocean currents are needed to be able to properly model the trajectory of the spill at both regional (open sea) and local level (coastline), just as to account for temporal variability. Moreover, a large number of particles, just as a high-resolution grid, are unavoidable in order to ensure accurate modeling of oil concentrations, of utmost importance in risk assessment, so that threshold concentrations can be established (threshold concentrations tell you what level of exposure to a compound could harm marine organisms).</p><p>In this study, an innovative methodology has been accomplished for the purpose of optimizing modeling configuration: number of particles and grid resolution, in the modeling of an underwater blowout, with a view to accurately represent oil concentrations, especially when threshold concentrations are considered. In doing so, statistical analyses (dimensionality reduction and clustering techniques), just as numerical modeling, have been applied.</p><p>It is composed of the following partial steps: (i) classification of i representative clusters of forcing patterns (based on PCA and K-means algorithms) from long-term wind-ocean current hindcast data bases, so that forcing variability in the study area is accounted for; (ii) definition of j modeling scenarios, based on key blowout parameters (oil type, flow rate, etc.) and modeling configuration (number of particles and grid resolution); (iii) Lagrangian trajectory modeling of the combination of the i clusters of forcing patterns and the j modeling scenarios; (iv) sensitivity analysis of the Lagrangian trajectory model output: oil concentrations,  to modeling configuration; (v) finally, as a result, the optimal modeling configuration, given a certain underwater blowout (its key parameters), is provided.</p><p>It has been applied to a hypothetical underwater blowout in the North Sea, one of the world’s most active seas in terms of offshore oil and gas exploration and production. A 5,000 cubic meter per day-flow rate oil spill, flowing from the well over a 15-day period, has been modeled (assuming a 31-day period of subsequent drift for a 46-day modeling). Moreover, threshold concentrations of 0.1, 0.25, 1 and 10 grams per square meter have been applied in the sensitivity analysis. The findings of this study stress the importance of modeling configuration in accurate modeling of oil concentrations, in particular if lower threshold concentrations are considered.</p>


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