页岩解决方案：生物表面活性剂——经济高效的流量保证的未来

定制的绿色处理在可持续性和更有效的石油采收方面优于传统处理。

Locus Bio-Energy Solutions 的 Jonathan Rogers 和 Amir Mahmoudkhani 博士

[编者注：这个故事的一个版本出现在 2020 年 5 月版的 E&P中。在这里订阅杂志 。]

容易石油的日子已经过去了。据《华尔街日报》报道，过去 5 年钻探的油井开采的石油和天然气量低于业主向投资者预测的水平，预计未来 30 年的缺口将超过 1 桶（500 亿美元）。二叠纪的递减曲线尤其陡峭且效率相对较低，原始石油采收率仅在 2% 至 8% 之间。2018 年，美国地质调查局估计，超过 46 桶石油、280 Tcf 天然气和 20 桶液化天然气被困在这些低渗透页岩地层中。换句话说，在提高页岩油和致密油采收率方面有一个巨大的奖励。

公司需要低成本的尖端技术，能够经济高效地最大限度地保证流量并延长衰退井的寿命。

勘探与生产
新的生物表面活性剂生产方法消除了成本和规模化挑战，从而可以开发高纯度和均质的方法。（来源：Locus 生物能源解决方案）
石油基表面活性剂、化学品

数十年来，石油基表面活性剂和化学品一直主导着维护和油井增产处理，以促进碳氢化合物的回收。大多数钻井和生产相关化学品（例如，返排助剂、破乳剂和缓蚀剂、蜡和沥青质抑制剂）都依赖于这些表面活性化学品的有效性。表面活性剂可降低界面张力并改变润湿性，使其成为钻井、完井和生产化学市场的重要添加剂，如返排助剂、石蜡分散剂和增产化学品，以调动常规和非常规油藏中残留的、不可移动的石油。

在过去的 50 年里，这些化学衍生的表面活性剂的性能足以满足石油工业的需求。然而，当今不断变化的操作条件，包括低孔隙率、高压/高温油藏，再加上对环境友好、可持续、可生物降解和具有成本效益的化合物的推动，催生了对表面活性剂技术新进展的需求，即生物表面活性剂。

生物表面活性剂概述

生物表面活性剂是由微生物产生的具有极性（亲水）和非极性（疏水）基团的表面活性两亲物。几十年来，微生物在油藏中原位生产的生物表面活性剂一直是一种公认​​的做法，微生物 EOR (MEOR) 于 1946 年首次获得专利。到 2007 年，MEOR 审查显示，美国油井的 EOR 成功率为 78%，来自油藏的生产微生物代谢产物，如非离子和阴离子微生物表面活性剂，具有化学表面活性剂无法比拟的多种功能和特性。在 MEOR 过程中，微生物和营养物质被注入油井，试图原位生产生物表面活性剂。然而，由于生物表面活性剂的微生物生成难以控制，结果并不一致。这些挑战引发了新的行业需求：一种在更受控的环境（非原位）中大规模生产这些代谢物且质量一致的方法，然后以与传统合成表面活性剂类似的方式将它们应用在需要的地方。

在过去的十年中，生物表面活性剂作为石油基表面活性剂的替代品在油田应用中的使用不断增加。除了其绿色环保特性之外，生物表面活性剂作为优异的润湿剂也非常有吸引力，并且具有非常低的临界胶束浓度（最小有效剂量率），从而将表面和界面张力降低到极低的水平。

生物表面活性剂的优点

天然衍生的生物表面活性剂比合成表面活性剂具有显着优势，例如增强的性能、环境相容性、低毒性、生物降解性以及在极端温度、盐度和 pH 值条件下保持活性。生物表面活性剂成本低廉，可完全生物降解，并且在生产过程中不会留下有毒废物。

生物表面活性剂的优势来自于其多种作用机制，包括渗透油藏以降低粘度、分散堵塞物、改变界面张力和油/水接触角，以及动员原本不流动的石油，最终提高产量。这些生物表面活性剂取代并优于传统的合成表面活性剂，其用量仅为传统表面活性剂用量的一小部分（在某些测试中仅为传统表面活性剂用量的 1/50），并且对环境没有有害影响。

消除限制

尽管生物表面活性剂在油田应用中使用具有巨大优势，但有限的制造能力和高生产成本以前是阻碍市场增长的主要制约因素。生产过程中的生物表面活性剂回收和纯化阶段是最昂贵和最耗时的，导致大规模生产效率低下，因此不再作为可行的选择。

最近开发的新生产方法消除了这些限制，这些方法可以提供非转基因、高效和定制的生物表面活性剂，生产成本比传统工艺低不到 10%。该生产技术由 Locus Bio-Energy Solutions 开发，可开发高纯度、浓缩且均质的生物表面活性剂。

该公司的生物表面活性剂以商业上可行的数量生产。定制方案包括鼠李糖脂、槐糖脂和甘露糖赤藓糖醇脂质，它们可将油和水的表面张力降低到比化学衍生的表面活性剂低得多的水平。这显着提高了许多石油开采过程的效率（包括溶解石蜡沉积物、降低重油粘度、降低油岩表面和界面张力）并降低毛细管力（阻力），从而增强石油通过油层的运动。岩石孔隙。

新一代生物表面活性剂为混相气体注入提供了低成本的潜在替代品，具有更高的非常规 EOR 效率、更好的流量保证和极低的资本支出。生物表面活性剂以低剂量率通过受控循环自吸方式注入储层，其中生物表面活性剂被泵入井中，浸泡 4 至 24 小时，然后回流。生物表面活性剂的作用改变了油藏的润湿性，降低了油与油藏岩石之间的界面张力或阻力，从而使原本不流动的油流动起来。在二叠纪和阿巴拉契亚地区处理的常规和致密砂油藏井中，超过 90% 的处理井的石油产量增加了 45% 以上，同时消除了石蜡沉积等流动保证问题。

结论

在当今价格较低的环境下，行业的焦点已转向运营总成本以及在现金流阈值内运作的需要。流量保证和生产配方旨在提供定制处理，平衡性能、环境风险和显着降低成本的要求。随着生物表面活性剂的推出，例如来自 Locus Bio-Energy 的针对单井挑战而定制的生物表面活性剂，该行业不再必须在环保产品和有效治疗之间做出选择。可持续性可以成为常态，而不是替代方案。

原文链接/hartenergy

Shale Solutions: Biosurfactants—the Future of Cost-effective Flow Assurance

Customized green treatments are outperforming conventional treatments in sustainability and more effective oil recovery.

Jonathan Rogers and Dr. Amir Mahmoudkhani, Locus Bio-Energy Solutions

[Editor's note: A version of this story appears in the May 2020 edition of E&P. Subscribe to the magazine here.]

The days of easy oil are in the past. According to the Wall Street Journal, wells drilled in the last five years are pumping less oil and gas than their owners forecast to investors, with the predicted shortfall estimated to be more than 1 Bbbl ($50 billion) over the next 30 years. Decline curves in the Permian are especially steep and relatively inefficient with recovery rates of original oil in place between only 2% and 8%. In 2018 the U.S. Geological Survey estimated that more than 46 Bbbl of oil, 280 Tcf of gas and 20 Bbbl of NGL are trapped in these low-permeability shale formations. In other words, there is a big prize to be claimed in terms of enhanced shale and tight oil recovery.

Companies need low-cost and cutting-edge technologies that can cost-effectively maximize flow assurance and extend the life of declining wells.

E&P
New biosurfactant production methods have eliminated cost and scaling challenges, allowing the development of highly pure and homogenous methods. (Source: Locus Bio-Energy Solutions)
Petroleum-based surfactants, chemicals

For countless decades, petroleum-based surfactants and chemicals have dominated maintenance and well stimulation treatments to facilitate the recovery of hydrocarbons. Most drilling and production-related chemicals (e.g., flowback aids, emulsion breakers and corrosion, wax and asphaltene inhibitors) rely on these surface-active chemicals for their effectiveness. Surfactants reduce interfacial tension and change wettability, making them essential additives for drilling, completions and production chemistry markets as flowback aids, paraffin dispersants and stimulation chemicals to mobilize residual, immobile oil from conventional and unconventional reservoirs.

Throughout the last 50 years, the performance of these chemically derived surfactants was sufficient to meet the demands of the oil industry. However, today’s changing operating conditions, including low-porosity, HP/HT reservoirs—combined with the drive for environmentally friendly, sustainable, biodegradable and cost-effective compounds—have created the need for new advances in surfactant technologies, namely biosurfactants.

Biosurfactants overview

Biosurfactants are surface-active amphiphiles with polar (hydrophilic) and nonpolar (hydrophobic) groups of substances produced by microorganisms. Biosurfactants produced in situ in the reservoir by microbes have been an accepted practice for decades, with microbial EOR (MEOR) first patented in 1946. By 2007 a MEOR review showed a 78% success in EOR across U.S. wells from the production in the reservoir of microbial metabolites, such as nonionic and anionic microbial surfactants, which offer a variety of functions and characteristics unmatched by chemical surfactants. In the MEOR process, microbes and nutrients were injected into oil wells in an attempt to produce biosurfactants in situ. However, the results were inconsistent as the microbial generation of biosurfactants were difficult to control. These challenges triggered a new industry need: a way to produce these metabolites at scale and of consistent quality in a more controlled environment (ex situ) and then apply them where needed in a similar manner to traditional synthetic surfactants.

The use of biosurfactants as alternatives to petroleum-based surfactants in oilfield applications has grown throughout the past decade. Aside from their green profile, biosurfactants are highly attractive as excellent wetting agents and have remarkably low critical micelle concentrations (minimum effective dosage rates), which reduce surface and interfacial tensions to extremely low levels.

Biosurfactants advantages

Naturally derived biosurfactants offer significant advantages over synthetic surfactants, such as enhanced performance, environmental compatibility, low toxicity, biodegradability and maintained activity under extreme conditions of temperatures, salinity and pH values. Biosurfactants are also low cost, completely biodegradable and leave no toxic waste from their production processes.

The advantages of biosurfactants come from their multiple mechanisms of action, including penetrating the oil reservoir to reduce viscosity, dispersing blockages, changing interfacial tensions and oil/water contact angles, and mobilizing otherwise immobile oil, ultimately increasing production. These biosurfactants replace and outperform traditional, synthetic surfactants at a fraction of the dosage rates (in some tests as little as 1/50th of the dosages of traditional surfactants) and with no hazardous effects to the environment.

Limitations eliminated

Despite substantial advantages of biosurfactant use in oilfield applications, limited manufacturing capacities and high-production costs were previously a major constraining factor that hampered market growth. The biosurfactant recovery and purification stage of the production process, which was the most expensive and time-consuming, made large-scale production inefficient and removed it as a viable option.

These limitations have been eliminated with the recent development of new production methods that deliver non-GMO, high-potency and customized biosurfactants at reduced production costs of less than 10% of traditional processes. This production technology, developed by Locus Bio-Energy Solutions, enables the development of highly pure, concentrated and homogenous biosurfactants.

The company’s biosurfactants are produced in commercially viable quantities. The customized program includes rhamnolipids, sophorolipids and mannosylerythritol lipids, which reduce oil and water surface tensions to much lower levels than chemical-derived surfactants. This significantly increases the efficacy of numerous oil extraction processes (including the solubilization of paraffin deposits, viscosity reduction of heavy oils, reduction of oil-rock surface and interfacial tension) and decreases capillary forces (drag), which result in enhanced oil movement through the rock pores.

This new generation of biosurfactants offers low-cost potential alternatives to miscible gas injection with higher unconventional EOR efficiency, better flow assurance and extremely low capex. The biosurfactants are injected at low dosage rates into the reservoir in controlled cyclic imbibition, where a biosurfactant is pumped into the well, allowed to soak for 4 to 24 hours and then allowed to flow back. The action of the biosurfactant changes the wettability of the reservoir, reducing the interfacial tension or drag between the oil and reservoir rock to mobilize otherwise immobile oil. Conventional and tight sand reservoir wells treated in the Permian and Appalachia have shown oil production increases of over 45% in more than 90% of the treated wells, together with the elimination of flow assurance problems such as paraffin deposition.

Conclusion

In today’s lower-price environment, the industry’s focus has turned to the total cost of operations and the need to function within a cash flow threshold. Flow assurance and production formulas aim to provide customized treatments that balance performance, environmental risks and requirements for significant cost reduction. With the introduction of biosurfactants, such as those from Locus Bio-Energy that are tailored to the challenges of individual wells, the industry no longer must choose between environmentally friendly products and treatments with effective results. Sustainability can be the norm rather than the alternative.