稠油微生物多轮次吞吐技术研究

Multicyclic Microbes Huff-Puff for Improving Heavy Oil Recovery in Liaohe Oil Fields

将菌种与无机培养基、稠油混合．在37℃培养3天，根据稠油乳化分散情况，对大量菌种进行筛选、复筛、驯化、复壮、富集．得到了传代性能优良、能适应辽河锦45块、千12块稠油油藏的几株菌并进行了性能评价。这些菌均由数个菌落组成，可以液蜡、原油为碳源、无机和有机氮为氮源、磷酸根为磷源生长．产表面活性剂和酸（由发酵液表面张力和pH判定），可降解稠油．使其黏度降低20％左右，好氧培养条件的降黏效果优于厌氧培养条件。优选菌种11、Lj1和21在培养液中菌数〉10^4个／mL时对稠油具有良好的乳化分散能力。在两区块13口高含水、低产量、低蒸汽效能、高轮次蒸汽吞吐井上．进行了首轮次微生物吞吐试验，处理半径3m。混合菌发酵液注入量2．0～9．8m^3．关井时间不少于7～9天。与末轮次蒸汽吞吐相比，6口井产油量增加，6口井产油量减少，但产出远大于投入，这12口井为有效井，其中又有6口井产出液中菌数降到10^4个／mL后实施了二轮次微生物吞吐。介绍了2口井微生物吞吐情况和效果，其中1口井已实施二轮次吞吐。以微生物和蒸汽单价比代替注蒸汽量计算油汽比，称之为拟油汽比。图4表7参3。

Through screening, rescreaning, acclimation, rejuvenation, and enrichment by the way of mixing the culture with inorganic nutrients and crude oils, cultivating the mixture at 37℃; in 3 days and investigating the emulsification/dlspersion of viscous oils, several bacterial strains are obtained for use in EMOR in heavy oil reservoirs of blocks Jing-45 and Qian-12, Liaoha, and evaluated for their properties. Composed of two or more colonies, these bacteria maintain activity in passage from generation to generation, grow well on liquid paraffin and crude oils as carbon source, on inorganic and organic nitrogen compounds as nitrogen source and on phosphates as phosphorus source, produce surfactants and acids as shown by the surface tension and pH value of the froth and degrade heavy oils more notably at aerobic conditions than at anaerobic conditions with oil viscosity decreased by some 20%. The selected bacterial strains, 11, Lj1, and 21, in cultures of bacterial population 〉 10^4 cell/mL possess good emulsifylng/dispersing capacities for heavy oils. On 13 steam huff-puff （SH-P） wells of Jing-45 and Qian-12 reservoirs, characterized by high water cut, low oil productivity, low steam stimulating efficiency and high cycles of steam injection reached, field trials on microbes huff-puff （MH-P） of first cycle have been performed with treating radius 3 m, volume of broth injected per well 2.1-9.8 m^3, and downhole fermentation time no less than 7-9 days. In comparison with the last cycle of SH-P, MH-P trials in 12 wells are effective： a raise in oil output observed in 6 wells and a drop in oil output but a beneficial economic input-to-output ratio-in another 6 wells. On 6 of these 12 wells, the second cycle of MH-P has been conducted after the microbial population in produced water decreased down to 104 cell/mL. The operations and results of MH-P on 2 wells are presented in some deiail and on one well of the 2 the second cycle of MH-P is reached. The oil-to-steam ratio in MH-P is determined using cost ratio of microbes to steam instead of mass of steam injected and is named as ＂pseudo oil-to-steam ratio＂.