The Field Application of a Scale Inhibitor Squeeze Enhancing Additive

1997 ◽  
Author(s):  
I.R. Collins ◽  
L.G. Cowie ◽  
M. Nicol ◽  
N.J. Stewart
Keyword(s):  
Field Application ◽  
Scale Inhibitor

A Game Changer in Scale-Squeeze Technology

2021 ◽  
Vol 73 (02) ◽  
pp. 40-43
Author(s):  
Paula Guraieb ◽  
Ross Tomson ◽  
Victoria Brooks ◽  
Ji-young Lee ◽  
Jay Weatherman
Keyword(s):  
Field Trials ◽  
Field Application ◽  
Third Party ◽  
Reservoir Rock ◽  
Formation Damage ◽  
Scale Inhibitor ◽  
No Formation ◽  
Intact Core ◽  
Large Improvement

Background Field trials using a new scale-inhibitor technology that improves treatment lifetime of scale squeezes have been successfully performed in the Gulf of Mexico. Tomson Technologies, in partnership with Shell, developed proprietary nanoparticle carriers that enhance scale-inhibitor adsorption to the reservoir and control the return rate for extended periods of time. This technology results in less chemical bleed off in the initial flowback and increases the chemical retained in the reservoir, allowing for more effective squeeze treatments. Both nanoparticle-enabled phosphonate and polymer inhibitors have now been developed and successfully squeezed in the field. Phosphonate inhibitors are widely used for squeeze treatment due to their desirable adsorption and release properties in carbonate and sandstone reservoirs. Minor changes have been made to the chemistry, but overall, the fundamentals have remained unchanged for decades. Polymeric scale inhibitors have also been developed for cases in which phosphonates are not applicable. The nano-enhanced technology provides a large improvement of treatment lifetime of 2 to 4 times (200-400%) when compared to incumbents, making this technology advancement attractive even in cases where current squeezes are considered successful. The well selected for this case study is an offshore formation with a predominantly sandstone mineralogy (approximately 80% quartz) with 25-30% porosity and bottomhole temperature of 183°F (83°C). Technology From the Lab to Field A sandpack sample from the trial well was used in the laboratory to deter-mine the adsorption and desorption properties of the nano-enabled inhibitor in realistic rock conditions. Multiple conditioning steps were used before product was injected in a sequence that mimicked field squeeze treatments. Mass-balance results from the sandpack experiment show adsorption of approximately 8 mg of polymer retained per gram of crushed reservoir rock used in the experiment. A typical rule of thumb for phosphonate-scale inhibitors (only as a comparison since this is a polymeric scale inhibitor) is 1-2 mg of inhibitor retained per gram of rock. Therefore, this is considered a large improvement on adsorption. There are challenges associated with measuring polymers in brine as residuals; however, multiple methods, both in-house and external, were com-pared to ensure accuracy. The results using the nano-enhanced scale inhibitor show concentrations higher than 1 mg/L of active polymer for over 7,000 pore volume of return in the sandpack experiment. Complete intact core experiments were also conducted with reservoir fluids and showed no formation damage during the injection of the product with regained oil permeability of 96%. Oil permeability was in the 150-200 mD range for the intact core experiments. Third-party coreflood testing was performed with nitrified and foamed stages to ensure compatibility with the nano-enabled chemistry. No formation damage was observed with the nitrification of the stages containing the nano-enabled chemistry. Field Application Case Study After extensive lab validation of the product and supporting corefloods to de-risk the technology, Well A was selected by Shell to be the first well treated with the new nano-enabled extended-lifetime inhibitor.

Field Application of a Scale Inhibitor Squeeze Enhancing Additive

1999 ◽  
Vol 14 (01) ◽  
pp. 21-29 ◽  
Author(s):  
I.R. Collins ◽  
L.G. Cowie ◽  
M. Nicol ◽  
N.J. Stewart
Keyword(s):  
Field Application ◽  
Scale Inhibitor

Formation Damage Induced by Chemical Treatments: Case Histories

2005 ◽  
Vol 127 (3) ◽  
pp. 214-224 ◽  
Author(s):  
Hisham A. Nasr-El-Din
Keyword(s):  
Field Studies ◽  
Field Application ◽  
Significant Decline ◽  
Formation Damage ◽  
Scale Inhibitor ◽  
Case Histories ◽  
Damage Mechanisms ◽  
Chemical Treatments ◽  
Remedial Actions

This study discusses formation damage mechanisms that were caused by commonly used chemical treatments. The chemicals used in these treatments included a scale inhibitor, a biocide-corrosion inhibitor, an in situ gelled acid, a full-strength mud acid, and a mutual solvent. These treatments were designed to remove a known form of formation damage. However, they created new forms of formation damage, which resulted in a significant decline in the performance of the treated wells. Case histories that illustrate the initial and new formation damage mechanisms are explained in detail. Laboratory and field studies that were performed to identify these mechanisms are discussed. Moreover, this paper highlights the remedial actions and field application that resulted in restoring the performance of various wells without affecting the integrity of the formation (both carbonate and sandstone). Finally, recommendations are given to minimize formation damage due to various chemical treatments.

Novel Scale Inhibitor Extends Treatment Lifetimes in Permian EOR

2021 ◽  
Vol 73 (08) ◽  
pp. 38-40
Author(s):  
Paula Guraieb ◽  
Ross Tomson ◽  
Anna Courville ◽  
Vaibhav Nikam ◽  
John Kennedy ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Calcium Sulfate ◽  
Effective Field ◽  
Field Application ◽  
Core Material ◽  
Co2 Flooding ◽  
Scale Inhibitor ◽  
Data Set ◽  
Minimum Effective Concentration ◽  
Group 2

Background A new extended-release (ER) scale-inhibitor technology showing significantly increased lifetimes has been applied in the Permian Basin. Tomson Technologies and Group 2 Technologies, in partnership with Occidental Petroleum (Oxy), implemented a scale-squeeze program for this carrier system. It allows for fewer squeeze treatments, which results in lower chemical usage, decreased plugging risk, and reduced environmental impact. Squeeze programs are an effective field treatment strategy to prevent scale formation in wells for extended periods of time. However, in some cases, squeeze lifetimes can be short, leading to frequent re-squeezing and production decreases, lowering overall economic recoveries. The ER phosphonate-based chemistry (SI1313) was used in selected wells where incumbent (previous chemical provider) treatment lifetimes were shorter than expected. The incumbent squeeze volumes and additives were used, and the scale-inhibitor (SI) chemistry was replaced with SI1313 to obtain directly comparable results. The wells selected are vertical wells, with predominantly carbonate mineralogy and 14–18% porosity and 9–16 mD permeability. Bottomhole temperature is 105°F (40°C). These wells are under continuous CO2 flooding operations, and the scales of interest are calcium carbonate and calcium sulfate predominantly. The selected wells were targeted to have a good squeeze history for comparison and stable water production. Pre-Job Validation Work Coreflood laboratory experiments were performed to simulate the adsorption and desorption under these specific Oxy Permian conditions. The coreflood showed over 10,000 pore volume (PV) of flow with inhibitor concentration remaining above the minimum effective concentration (MEC) during the entire run. Once greater than two times incumbent performance was reached, the coreflood was stopped, although the return concentration was still above MEC. For reference, corefloods with incumbent phosphonate chemistry under the same conditions usually drop below MEC around approximately 3,000–5,000 PVs. The adsorption of SI1313 to core material was measured during the coreflood experiment and the results show 12.5 mg of inhibitor adsorbed per gram of core material. As a comparison, a typical incumbent phosphonate scale inhibitor adsorbs 1–2 mg of inhibitor per gram of core material. This increase in adsorption is considered a large improvement over traditional chemistry. The carrier platform’s superior adsorption, when combined with controlled desorption, is the basis for extending the lifetimes of scale- inhibitor treatments. The corefloods results validate the ER characteristics expected from SI1313 and allowed for field squeezes to be conducted. Field Application Group 2 Technologies provided SI1313 to be squeezed for Oxy in January 2020, into five vertical conventional wells. The selected wells are in one area where CO2 flooding is in place and there is risk of calcium carbonate (CaCO3) and calcium sulfate (CaSO4) scaling. These wells have had many scale squeezes performed on them, yielding an excellent data set to compare against. The goal of this trial was to show significant lifetime extension compared to previous incumbent squeeze lifetimes.

The Influence of Turbulence (or Hydrodynamic Effects) on Strontium Sulphate Scale Formation and Inhibitor Performance

2014 ◽  
Author(s):  
Clare Johnston ◽  
Louise Sutherland
Keyword(s):  
Barium Sulphate ◽  
Test Methods ◽  
Standard Test ◽  
Field Application ◽  
Scale Formation ◽  
Test Method ◽  
Scale Inhibitor ◽  
Modified Method ◽  
Bottle Test ◽  
The Impact

Abstract Inorganic scale (carbonate, sulphate and sulphides) formation can be predicted from thermodynamic models and over recent years better kinetic data has improved the prediction of such scales in field conditions. However these models have not been able to predict the observed deposition where flow disturbances occur, such as at chokes, tubing joints, gas lift valves and safety valves. This can lead to unexpected failures of critical equipment such as downhole safety valves (DHSV’s), and operational issues such as failure to access the well for coiled tubing operations due to tubing restrictions. In recent years it has been recognised that the turbulence found at these locations increases the likelihood of scale formation and experiments have been able to demonstrate that increased turbulence also impacts the minimum scale inhibitor concentration required to prevent scale. One of the industry standard test methods used to screen inhibitors for sulphate scale inhibition is the static bottle test. In this paper the ‘static’ bottle test method is modified to investigate the effects of increasing levels of turbulence on the formation of strontium sulphate scale at a fixed brine composition. Using this modified method it has been possible to demonstrate the impact of varying turbulence on the performance of two common generic types of scale inhibitor (phosphonate and vinyl sulphonate co-polymer). Data on the mass of scale formed, scale morphology using SEM imaging and inhibitor efficiency will be linked to degree of turbulence and scale inhibitor functionality (nucleation inhibition vs. crystal growth retardation). This study builds on the previously published10 findings for barium sulphate which showed phosphonates were less affected by turbulent conditions by carrying out similar tests on strontium sulphate. A clear mechanistic conclusion can now be drawn for sulphate scale formation and inhibition under increasingly turbulent conditions. The findings from this study have a significant impact on the methods of screening scale inhibitors for field application that should be utilised and development of suitable inhibitors that perform better under higher shear conditions.

Influence of Calcium and Bicarbonate Ions on the Kinetics of CaCO3 Formation at High Temperature in the Absence and Presence of Scale Inhibitors

2014 ◽  
Author(s):  
Bo Xu ◽  
Tao Chen ◽  
Ping Chen ◽  
Harry Montgomerie ◽  
Thomas Hagen ◽  
...  
Keyword(s):  
Saturation Index ◽  
Poor Performance ◽  
Field Application ◽  
Scale Formation ◽  
Laboratory Evaluation ◽  
Scale Inhibitor ◽  
Bicarbonate Ions ◽  
High Calcium ◽  
Produced Waters ◽  
Kinetics Of

Abstract The calcium and bicarbonate ions, present in the produced waters in the oilfields, are two major scaling ions in CaCO3 formation. In the last decade, a lot of studies have been focused on the thermodynamic or kinetics of CaCO3 formation, including the effects of scaling ions, temperature, pH, pCO2, etc. Seldom studies are focused on the kinetics of calcium carbonate surface deposition with different levels of calcium and bicarbonate, especially in the presence of scale inhibitors. In the work reported herein, dynamic loop tests were carried out to study the kinetics of CaCO3surface deposition in three typical produced waters (Water-1, high calcium and low bicarbonate; Water-2, medium calcium and medium bicarbonate; Water-3, low calcium and high bicarbonate) with same saturation index (SI) at 150°C. Typical scale inhibitor chemistries, including phosphonate, polycarboxylic, polymaleic, polysulphonate, polyacrylic, polyaspartate based scale inhibitors, have been tested in three tested waters. The following conclusions are drawn based on the test results. SI generated by applied prediction software is a parameter indicating the thermodynamic driving force. The kinetics of scale formation, more representative field conditions, should be studied as well to give a guideline of scale formation in the fields.Comparison of calcium, bicarbonate is the dominant kinetic factor for CaCO3 formation in the absence and presence of inhibitors.Higher bicarbonate water, higher minimum inhibitor concentration (MIC) is requested, even the three tested waters with a same SI.The ranking of the performance of scale inhibitor are dependent on the water chemistries and inhibitor chemistries. Some of the best ranking phosphonates in Water-1 and Water-2 with low and medium bicarbonate showed poor performance on Water-3 with high bicarbonate. Some polymers showed contrary ranking performance. This paper gives a comprehensive study of the kinetics of CaCO3surface deposition considering the effects of calcium and bicarbonate, including prediction, laboratory evaluation, mechanisms and inhibitor selection. It will contribute to understand the kinetics of CaCO3 formation and recommend effective inhibitors for field application. Environmentally acceptable inhibitors have been developed for different CaCO3 water chemistries at elevated temperature and are suitable for applications through squeeze treatment or continuous injection.

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