摘要
深层页岩气是中国未来天然气产业发展的重要领域,目前已初步实现了工业化开发,成功获得一批高产井,落实了第二个万亿方储量、百亿方产量上产区,实现了深层页岩气富集规律与勘探开发技术创新突破,推动中国页岩气规模有效上产。美国4大深层页岩气区块已实现工业化开采,深层页岩气产量不断攀升,2021年产量达3132×108 m3,占美国天然气总产量的41%。系统总结提出了川南海相深层页岩气6大富集特征:①强还原环境的深水陆棚沉积,有利于有机质富集和保存;②优质储层厚度稳定,大面积连续分布;③断裂封闭性较好,普遍超高压;④有机孔和裂缝发育,储层物性较好;⑤深层页岩含气性好,页岩气资源落实度高;⑥深层页岩游离气比例高,单井初期产量高。结合中国深层页岩气富集特征及勘探开发进展,指出实现深层页岩气效益开发面临的3项挑战和对应攻关方向。展望提出四川盆地海相深层页岩气可探明页岩气地质储量(3~5)×10^(12)m^(3),具备上产(300~500)×10^(8)m^(3)的开发前景。建议坚持攻关,秉承“极限动用”理念,精准构建页岩储层“透明地质体”,采用最优工程技术手段,优化生产制度,最大限度提高EUR(单井评估最终可采储量),持续降低开发成本,不断突破页岩气开发极限,实现中国页岩气产业的进一步发展。
Deep shale gas reservoirs are vital for the future development of China’s natural gas industry.Presently,China has achieved preliminary industrial exploitation in this regard,as evidenced by the successful drilling of several highyielding wells,the delineation of the second gas production growing area with estimated gas-in-place of around one trillion cubic meters and gas production of around ten billion cubic meters,and innovative breakthroughs in research on shale gas enrichment pattern together with exploration and exploitation technologies.These have facilitated the large-scale,effective shale gas production growth in China.Meanwhile,the United States has achieved industrial exploitation of four major deep shale gas blocks,leading to constant rise of the shale gas production from deep reservoirs reaching 313.2×10^(9)m^(3)in 2021,which accounts for up to 41%of its total natural gas production.Through systematical summary,we determine six major shale gas enrichment characteristics for deep marine reservoirs:(1)deepwater shelf deposits in a strong reducing environment,which are favorable for organic matter enrichment and preservation;(2)high-quality reservoirs with stable thicknesses and a continuous distribution in large scale;(3)prevalent ultra-high pressure with good sealing capacity of faults;(4)well-developed organic pores and fractures,resulting in favorable reservoir physical properties;(5)superior gas-bearing property of deep shales where shale gas resources are available;and(6)a high proportion of free gas in deep shales,leading to high single-well production in the initial stage.Despite these characteristics as well as advancements in the exploration and exploitation of deep shale gas reservoirs in China,three challenges are posed in the study along with corresponding countermeasures for profitable shale gas extraction from deep reservoirs.Prospects show that deep marine shale gas reservoirs in the Sichuan Basin hold discovered shale gas in place of(3~5)×10^(12) m³,suggesting potential gas production growth of(30~50)×10^(9) m^(3).It is suggested to persist in tackling key problems,and accurately build a“transparent geological body”for shale reservoirs by adhering to the philosophy of maximizing producing reserves.Furthermore,we should focus on the optimal engineering techniques and production systems to maximize single-well estimated ultimate recovery(EUR),to continually reduce exploitation costs and consistently surpass current shale gas production limits,with the ultimate purpose of driving further progress in China’s shale gas industry.
作者
王红岩
周尚文
赵群
施振生
刘德勋
焦鹏飞
WANG Hongyan;ZHOU Shangwen;ZHAO Qun;SHI Zhensheng;LIU Dexun;JIAO Pengfei(National Elite Institute of Engineering,CNPC,Beijing 100096,China;National Energy Shale Gas Research and Development(Experiment)Center,Langfang,Hebei 065007,China;PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China)
出处
《石油与天然气地质》
EI
CAS
CSCD
北大核心
2023年第6期1430-1441,共12页
Oil & Gas Geology
基金
中国石油天然气股份有限公司前瞻性基础性战略性技术攻关项目(2021DJ19)。
关键词
富集特征
勘探进展
开发前景
页岩气
深层页岩
四川盆地
enrichment characteristic
exploration progress
potential gas production
shale gas
deep shale
Sichuan Basin