Efficient oil and gas production heavily relies on an effective microbial control program that accounts for the entire life cycle of operations. Adopting an integrated approach that considers the drilling, completion, and production stages has proven to be a successful strategy for managing troublesome microorganisms. However, selecting the most suitable microbial control program can be challenging due to various misconceptions. In this article, we debunk five prevalent myths surrounding microbial control treatments and emphasize their significance for production chemists.
Myth 1: All Biocides Are Created Equal Contrary to popular belief, not all biocides offer the same benefits.
While some biocides are designed for quick-kill protection, others are capable of sustaining efficacy under extreme downhole conditions, including high temperature and salinity. Each shale play and well is unique, making it crucial to tailor treatment programs according to specific environmental conditions and water properties. This might involve selecting different biocides or employing a combination of biocide chemistries. Today, the industry has access to a wide range of biocides, including those for near wellbore efficacy (e.g., glutaraldehyde and tetrakis (hydroxymethyl) phosphonium sulfate) and those providing extended long-term protection (e.g., tris (hydroxymethyl) nitromethane, dimethyloxazolidine, and (chloroallyl)-triaza-azoniaadamantane chloride).
Myth 2: An Oxidizing Biocide Is Sufficient for Treatment The rapid action of oxidizing biocides, such as chlorine dioxide (ClO2), may be impressive, but these benefits are primarily limited to topside treatments.
Relying solely on oxidizers can create vulnerability downhole, leaving the well, reservoir, and produced water susceptible to microbial contamination.
Myth 3: Saving Money by Skipping Biocides While economic conditions may lead operators to consider cutting costs, eliminating microbial control programs altogether can result in severe consequences.
Untreated systems are at risk of uncontrolled microbial contamination, leading to costly issues like souring, corrosion, and equipment plugging throughout the well’s lifecycle. Initial savings from not purchasing biocides can be overshadowed by long-term expenditures on mitigating these problems.
Myth 4: No Long-Lasting Biocide Needed in Extreme Temperatures The idea that biocides are unnecessary in extreme temperatures has dissuaded some producers from implementing an integrated biocide program.
However, certain thermophilic bacteria can thrive in environments up to 120°C (248°F). Temperature gradients from surface operations to the wellbore may provide niches where bacteria can proliferate, potentially leading to issues like microbially induced corrosion, equipment plugging, and souring.
Myth 5: Chlorine Dioxide (ClO2) Is Cost-Efficient When evaluating the cost of a biocide program, it’s essential to distinguish between cost per unit and total cost to treat.
Although ClO2 is perceived as cost-effective, non-oxidizing oil and gas biocides like THPS, glutaraldehyde, and glut/quat blends can yield annual savings ranging from 10% to 50%. Effective microbial control can prevent expenses related to compatibility issues, the need for sweetening soured hydrocarbons, equipment replacement, or biofilm removal.
Conclusion: As oil and gas operators navigate market fluctuations, ensuring the right biocide program is crucial. Microbial control expertise, a diverse product portfolio, and advanced testing capabilities empower biocide suppliers to design integrated microbial control programs that enable operators to extract oil and gas efficiently and cost-effectively. Production chemists play a vital role in implementing these strategies to safeguard well production from microbial-related issues, contributing to the industry’s overall success.
AMPP is currently working on a new biocide standard for biocide testing. As a production chemist, you should introduce a proper strategy for biocide control. Teststing the effectiveness of a biocide is a crucial element of biocide control. The technical standard from AMPP (AMPP TM0194) describes the methods that can be used in field conditions. Parallel to this, there is a current initiative to develop a new biocide testing standard. Susmitha Kotu (DNV GL) is leading this process and gives a brief overview of the developments at Corrosion Alliance (View video). Viewing the video requires a free registration at Corrosion Alliance.
