Acrolein can function under a variety of conditions as an effective hydrogen sulfide scavenger in oilfield waterflood systems. The scavenging ability is maximized in waters having a pH range of 6 through 8, a total dissolved solids level below 1 %, and temperatures less than 149°F [65°C].At least 4 ppm acrolein is necessary to achieve sufficient reaction of each original 1 ppm hydrogen sulfide. This reaction req~ires about 2to 20 minutes, depending on the natQre of the system. Although' sand, garnet, or diatornacequs earth filters do not affect the scavenging ability of acrolein, charcoal fIlters, large tanks, long pipelines, higb~temperature WepJ.cos, and rebbilers can produce diwillished effects. Further diminished effects also can be produced when incQpJ.patible chemicals are used concurrently with acrolein. Some application techniques that can lessen or eliminate these adverse conditions I;lre presented.
IntroductiOI}Hydrogen sulfide has beed both a corrosive and a toxic nuisancl! to oilfield operations for decades. Although an abundance of literature describing the abatement of hydrogen sulfide in gas and drilling mud systems is ~vailable, these techniques and environments do not appear to have significant utility in oilfield waterflood operations. Related industries-such as the geothermal, the plllp and paper, and the was!ewater j.ndustries-appear to rely on aeration, 1,2 bacteria, 3,4 chemi~al scavengers, 5-7 me~lic salt and oxide beds,8-15 and oxidizers. 16'21 ~though some of these methods are applicable to oilfield waterftood operations, the majority appear impractical befause of cost and compatibility considerations.SpeCific oilfield waterflood operations ~ave used mechabical and chemical technofqgies in an attempt to reQlove hydrogen sulfide from native waters. Some me-chjPrical methods involve aeration, anion exchange resins, degassing, dis~illation, steam reform~ng, and zeolite spfteners. 22 ,23 Most of these methods are viewed currently as being expensive or impractical.