摘要
砂巖酸化技術是油氣井穩產、增產,注水井降壓、增注的主要工藝措施之一,目的是通過酸液在地層孔隙的晶間、孔隙及微裂縫中的流動和反應,來溶解井眼附近地層在鉆井、完井、修井及注水等過程中的各種固相微粒、雜質,解除其對地層滲透率的傷害,疏通流體滲流通道,從而恢復和提高單井的產能。
本文針對JZ25-1S 油氣田高孔高滲油田開發的特殊性,并結合海上酸化作業的難點,開展了這類油藏儲層傷害機理和類型、增產機理、優選酸液體系、酸液分流技術、酸化工藝參數優化等研究。通過研究對酸化機理及其影響因素有了全面認識,篩選出了適合JZ25-1S油氣田的酸液體系和適合的酸液分流技術并對施工參數進行優化。工藝技術、酸液體系的研究成果最終形成了實用的高孔高滲非均質砂巖油藏酸化對策和配套酸化工藝技術,對國內外類似砂巖儲層酸化都有借鑒。
關鍵詞:酸化模擬;砂巖酸化;儲層傷害;酸化工藝;基質酸化
Abstract
Matrix acidizing of the sandstone is one of the technical measures to stabilize or increase the production of a oil or gas well, lower the injection pressure and enhance the injection of a injection well. The aim is to dissolve the particle and impurity in the formation near the wellbore caused by drilling, workover and water injection, through the flow of acid in the pore, cavity and microcrack in the formation, so as to relieve the formation damage, dredge the flow channel, thus recover and enhance the production.
Aimed at the formation particularity of JZ25-1S oil and gas field, combined the difficulty of offshore acid, this paper presents the research of reservoir damage mechanism and types,the mechanism of stimulation, optimizing the acid fluid system, acid diversion technique, optimizing acid technology parameter. Through the research, we have fully understanding about acid mechanism and the damage factor, and we select the appropriate acid system and acid diversion technique, optimize construction parameter for JZ25-1S. The research accomplishment of acidizing technology, acid fluid system and not only formed practical sandstone acidizing countermeasure and complex acidizing technology and technique in BOHAI oil field, but also provided some experiences for the similar conditions in the whole world.
Key words: acid simulation; sandstone acid; formation damage; acid technology; matrix acid