METHOD OF NEUTRALIZATION OF HYDROGEN SULFIDE IN OIL WELL Russian patent published in 2002 - IPC

FIELD: oil and gas producing industry; applicable in neutralization of hydrogen sulfide in well in course of its operation under conditions of hydrogen sulfide aggression. SUBSTANCE: method provides for injection into well of neutralizing fluid in form of rated amount of product of reaction of monoethanol amine with 30-40% solution of formaldehyde (formalin) in mole ratio of 1:(2.1-3). In this case, in winter time, neutralizing fluid is used in mixture with aliphatic alcohol C₁-C₄ or with ethylene glycol taken in amount up to 40 vol.%. In preferable version, neutralizing fluid is continuously injected to annular space (to bottom hole) of well to flow of recovered well product in amount sufficient for neutralization of hydrogen sulfide and light mercaptans contained in well recovered product. Neutralizing fluid is injected to well annular space in form of preliminarily prepared emulsion of neutralizing fluid in oil. Used for preparation emulsion is a part of recovered oil, preferably, in amount of 2-20% of produced oil. In other version, neutralizing fluid is preliminarily injected into well with subsequent forcing to bottom-hole zone by displacing fluid, for instance, water or oil, or oil fraction (prior to well servicing). EFFECT: efficient neutralization of hydrogen sulfide and light mercaptane in well, extended assortment of accessible low-cost neutralizing fluids possessing high absorbing capacity with respect to hydrogen sulfide and light mercaptans. 6 cl, 1 tbl