川东YL地区陆相致密砂岩气藏埋藏深、岩性致密,压裂改造是实现该区域有效勘探开发的必要手段,但YL地区深层致密砂岩压裂改造面临着破裂压力超高、施工压力超高、闭合压力超高、排量提升困难、缝高控制困难等技术难题,大部分气井压后产能低且产量递减快.储层改造工艺技术能否取得突破,直接影响到了该地区的勘探开发进程.通过分析YL地区深层致密砂岩气藏的储层特征,总结前期现场实践中面临的技术难题及实施经验,提出一套适用于川东深层致密砂岩气藏的压裂改造工艺技术,可有效促进地区勘探开发工作,对同类型的深层致密砂岩压裂改造具有借鉴意义.

元坝地区陆相砂岩储层具有埋藏深、致密、岩性复杂、高压、高温、非均质性强、较薄、含气饱和度普遍较低等特点,气井通常需要进行储层改造后才能获得工业气流,但大部分气井改造难度大、压后产能低、产量递减快.通过对储层深入认识,分析了深层致密砂岩压裂改造难点,结合前期理论探索和现场实践,形成了适用于川东北深层致密砂岩气藏的压裂改造工艺的关键技术,重点解决施工压力高的难题,确保压裂过程的低伤害,提高了压裂规模,基本满足了探井测试需要,有效促进了地区勘探工作,对同类型的深层致密砂岩压裂改造也具有重要借鉴意义.

川东南焦石坝地区海相页岩气井具有地表和地下地质条件复杂、井壁稳定困难、井眼轨迹要求高、造斜段及水平段钻进困难、长水平段固井难度大等特点及难点,经过攻关研究,配套形成了三开井身结构、浅层气安全钻井、气体钻井、复合钻井、水平井钻井、油基钻井液、弹塑性水泥浆体系、钻头选型及参数优化以及地质跟踪导向等钻井技术,实现了该地区勘探井的优快钻井,有效支撑了勘探工作.

Hydraulic fracturing of deep shale reveals that high injection pressure ,low fracture conduc‐tivity ,limited stimulated reservoir volume ,and unsatisfactory primary production are mainly due to deep burial ,variable lithology and high in‐situ stresses .Based on the comprehensive evaluation of geological characteristics and fracturing potential of deep shale reservoirs ,technical difficulties in volumetric stimula‐tion were discussed and relevant countermeasures were proposed .Then ,a fracturing optimization method for deep shales was proposed ,and it combined a numerical simulation of the gas reservoir ,a calculation of induced stress and fracturing simulation .Fracturing segment/cluster ,perforation and stimulation treat‐ment parameters were analyzed .Taking Well Dingye 2HF as an example ,the implementation and control of deep shale fracturing techniques were discussed ,and the responses of stimulation pressure in field appli‐cation were identified .Through stage‐by‐stage optimization and fine adjustment of parameters in aspects of pad volume ,fracture initiation by gel ,and initial sand and fluid ratio .Finally ,a composite fracturing treatment procedure was formed ,i .e .pre acid + moderate viscosity gel + slick water + low viscosity gel+ moderate viscosity gel .The fracturing of deep shales has been improved successfully through the appli‐cation of the proposed procedure .In field application of Well Dingye 2HF ,12 stages of fracturing stimula‐tion were completed with initial gas production of 10 .5 × 104 m3/d after the treatment .This procedure will provide technical reference for hydraulic fracturing in similar deep shale gas reservoirs in the future .

The paper summarizes the history of the petroleum exploration of Cenozoic sedimentary basins in Yunnan Province, presents the recent achievements of oil and gas exploration and development in the basins of Luliang, Baoshan, Qujing and Jinggu. After analysing comprehensively the hydrocarbon potential of the Tertiary basins in Yunnan from regional geology structure, basin evolution and some formed hydrocarbon conditions, considers that there is a better prospect of petroleum exploration and development in these basins. This paper offers the detail suggestions for petroleum exploration, geology evaluation and further development for the future.

The gas reservoirs of Baoshan Gas Field are shallow, unconsolidated sandstone, water bearing and lithologic, whose times belongs to Neogene system. There are many thin producing zones in vertical section, which are poor connectivity in horizon. The reserves of most gas reservoirs are very small and their outputs are very low. So the demand of natural gas is exceeding its supply. The pilot field experiments of the multiple - sand commingled production technology were carried out with two gas wells of the gas field have achieved success. As a result, not only the gas production and the developing reserves are enhanced in a large scale to assure the balance of the demand and the supply of the natural gas, but also the problems of water and sandstone production are controlled effectively to prolong the water - free gas production period and the lives of the gas wells, and to enhance the recovery efficiency of the reserves of the gas reservoirs, so as to improve the effect of development evidently. In addition, implementing the technology of the multiple sand commingled production can enhance the rate of gas production, accelerate the pace of development and shorten the payback period, in order to realize the three - dimensional and highly efficient development of this small gas field.

Luliang gasfield and Baoshan gasfield are the typical small scale Tertiary gasfield in Yunnan,which are characterized by shallow buried depth,loose cementation and waters development.The identification of gas sand,reasonable complete exploitation well network,gas exploitation by water-controlling and sand-controlling, multilayer combination exploitation and gas exploitation by water extract,etc.are the important guarantee of successful exploitation of gasfield.