摘要
安塞油田长6段油藏渗透率为0．96～2．90mD，孔隙度为11．00％～13．25％，孔隙以小孔、细喉为主，地饱压差值仅为2．94～3．66MPa，油层供液能力差，为典型的特低渗透岩性储集层，此为油井低产的主要地质因素。胶结物中酸敏性矿物含量高（6．19％），是常规酸处理工艺造成储集层伤害的潜在因素。地层水矿化度高达89850mg／L，严重的油层结垢是造成单井产量降低的重要因素。在安塞油田实施暂堵压裂16口井，平均单井目增油1．85t，平均有效期84．1d；泡沫清洗10口井，平均单井日增油1．13t，平均有效期52．8d；酸处理99口井，平均单井日增油1.10t，平均有效期128．9d；清防垢处理18口井，平均单井目增油1．90t，平均有效期330d。分析认为，清防垢施工处理半径较大是结垢处理效果较好的主要原因。有效增大油层压裂和酸处理半径是进一步提高压裂和酸处理效果的有效途径。
The geology of Triassic Yanchang Formation in Ansai Oilfield is extrwlow permeability（0. 96 - 2. 90mD）, extra-low porosity（11. 00%-13.25%）, fractured oil reservoir with dominant small pores and throats, little differences between formation and saturation pressure （ 2.94 ～ 3.66 MPa）, high percentage of acid-sensitive minerals in cements （6.19 % ）, and high formation water salinity（89 850mg/L）. Severe scaling problems and production reductions appear in water flooding production wells. Fracturing treatments were performed in 16 production wells leading to an average increase of 1.85t/d per well in oil production, the average effective life was 84. ld; foam flushing was operated in 10 production wells, leading to an average increase of 1.13t/d per well, the average effective life was 52.8d; acidizing treatments in 99 production wells led to an average increase of 1.10t/d per well, the average effective life was 128.9d; scale control and removal treatments in 18 production wells led to an average increase of 1.90t/d per well, the average effective life was 330d. The better result of the scale control and removal treatment is mainly attributed to its larger radius. Enhancing the radius in fracturing and acidizing treatments can further improve their performance.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2006年第5期638-642,共5页
Petroleum Exploration and Development
基金
国家"西部开发"科技行动重大攻关计划项目(2005BA901A13)
关键词
特低渗透油藏
压裂
酸化
结垢防治
安塞油田
extra-low permeability reservoir
fracturing
acidizing
scale control and removal
Ansai Oilfield
