巴彦油田深层欠压实地层定向井优快钻井技术

巴彦油田地层沉降快速、欠压实,且岩性复杂,储层埋深超4000 m,平均井深超5000 m,钻井施工过程中易发生井壁失稳、定向井机械钻速慢、轨迹不易控制等问题,建井周期长达54.96 d。为此,开展了井眼轨道优化、个性化钻头优化设计、降摩减阻提速工具应用、钻井参数和钻井液性能优化。研究结果表明:1.2(°)/30 m降斜率利于研究区钻井施工;五刀翼PDC钻头浅内锥、异型齿和后排减震齿设计,可提升抗冲击能力,提高机械钻速;“水力振荡器+钻柱扭转控制系统”及“旋转导向+低速大扭矩螺杆”可以提高定向段机械钻速50%以上;“低钻压、高转速、大排量”的工程参数可使上部乌兰图克组地层提速9%以上,“高钻压、高转速、低排量”的工程参数使深部五原组、临河组地层提速14%以上;聚合物钻井液体系配合微纳米封堵剂,解决了井壁失稳复杂情况。现场应用11个平台90口井,平均机械钻速提高了8.89%,建井周期缩短23.94%。优快钻井技术推动了巴彦油田兴华1区块钻井大幅度提速,为同类油气藏快速建井、加快产能建设提供了借鉴。

巴彦油田深井高凝油藏试油完井一体化技术

针对巴彦油田深井高凝油藏在试油完井施工中存在工艺复杂、施工周期长、储层二次伤害严重、施工成本高等问题,通过分析现有的高温高压深井试油完井一体化技术特点及存在不足,结合临河油区油藏地质特征和原油物性特点,设计了3套试油完井一体化管柱,制定了相应的工艺流程,并对每种一体化工艺的特点及适用条件进行了分析。上述3种试油完井一体化技术已在现场成功试验14口井,其中压裂-射流泵排液一体化技术现场试验9口井,缩短施工周期2~3 d,有效提高了压裂后排液求产效率,降低了储层二次污染;完井投产一体化技术现场试验5口井,提高了自喷井和机抽井完井投产效率,缩短了单井完井周期,减少了储层污染,降低了作业成本。深井高凝油藏试油完井一体化技术的成功应用为巴彦油田勘探开发一体化进程高效推进提供了有力的技术保障,对国内同类型油藏试油完井技术研究具有指导借鉴意义。

巴彦油田试油测试关键技术

巴彦油田勘探开发已进入全新阶段,深井、高温高压井持续增多,岩性、油藏越来越复杂,试油测试难点突出,主要表现为原油凝固点高、储层埋藏较深、温度压力较高、地层易出砂、压差与高产矛盾突出等问题。针对试油测试难点,开展了试油测试关键技术研究,包括:高凝油射流泵高效排液技术,深井STV测试一体化技术,储层临界出砂压差预测技术,高凝油PVT高压物性取样技术,选层试采完井管柱投产技术等,这些技术的综合运用,可较好满足巴彦油田深井试油测试需求。

Petroleum geological features and hydrocarbon enrichment of Linhe Depression in Hetao Basin, NW China

Based on paleogeomorphology, drilling and seismic data, this paper systematically studies the structural and sedimentary evolution, source rock characteristics, reservoir characteristics and formation mechanism, hydrocarbon accumulation model and enrichment law in the Linhe Depression of the Hetao Basin, NW China. The Hetao Basin mainly experienced three stages of evolution, namely, weak extensional fault depression, strong extensional fault depression and strike-slip transformation, giving rise to four positive structural belts(Jilantai, Shabu, Nalinhu and Xinglong), which are favorable areas for oil and gas accumulation. The two main saline lacustrine source rocks, Lower Cretaceous Guyang Formation and Oligocene Linhe Formation, are characterized by high sulfur content, rich algae, early maturity, early expulsion, and wide oil generation window. The large structural transition belt in the intermountain area around the Hetao Basin controls the formation of large-scale braided river delta deposits, which are characterized by high quartz content(50%-76%), long-term shallow burial and weak compaction, low cement content, and good reservoir properties in delta front sandbody. The burial depth of the effective Paleogene reservoirs is predicted to reach 8000 m. Three hydrocarbon accumulation models, nose-uplift near sag, buried hill surrounding sag, fault nose near source rock, are constructed. The law of hydrocarbon accumulation in the Linhe Depression is finally clarified as follows: near-source around the depression is the foundation, high-quality thick reservoir is the premise, good tectonic setting and trap conditions are the key.

河套盆地临河坳陷石油地质特征与油气富集规律

基于古地貌、钻井和地震资料,对河套盆地临河坳陷构造沉积演化、烃源岩特征、储集层特征及形成机制、油气成藏模式与富集规律进行系统研究。结果表明:①河套盆地主要历经“弱伸展断拗期、强伸展断陷期和走滑改造期”3期成盆演化过程,发育吉兰泰、沙布、纳林湖、兴隆等4大环洼正向构造带,为油气富集成藏的有利区带;②发育下白垩统固阳组、渐新统临河组两套主力咸化湖相烃源岩,具有高含硫富藻、早熟早排、生油窗口宽的特征;③河套盆地周缘山间大型构造转换带控制形成大型辫状河三角洲沉积,三角洲前缘砂体具有石英含量高(50%~76%)、长期浅埋弱压实、胶结物含量低、储集层物性好的特点,预测古近系有效储集层埋深达8000 m;④构建邻洼鼻隆、环洼潜山、近源断鼻3种油气成藏模式,临河坳陷油气富集规律为“环洼近源是基础、优质厚储集层是前提、良好的构造背景和圈闭条件是关键”。