非常规油气时代的测井采集技术挑战与对策

Challenges and countermeasures of well logging data acquisition technology in unconventional petroleum exploration and development

为积极应对中国主要含油气盆地已经或即将进入非常规油气勘探开发的发展趋势,文章在概述非常规油气的储层、油气藏和工程等三方面特点基础上,系统分析了当前中国测井采集技术的现状、挑战及需求,并对标国际领先技术,系统性提出了相应发展对策,即:(1)升级常规电缆测井性能。研制并投产高精度高分辨率高安全型常规测井,要求纵向分辨率为5~10cm,密度测井精度为0.01~0.015g/cm3,并采用高产额可控中子管技术实现密度和中子的无放射源安全测井。(2)完善配套成像测井技术。一是重点研发短回波间隔(不大于0.2ms)、高纵向分辨率(10cm左右)和大信噪比(大于8)的同时探测纵向弛豫和横向弛豫二维核磁共振测井;二是完善发展适用于致密储层的矿物组分精细计算和流体性质准确识别技术,主要为元素全谱、多频介电、井下实时流体分析与测压及水平井多相流动成像等高性能成像测井技术;三是发展方位超远探测三维声波测井技术,精细描述水平井井旁地层结构、断裂系统、天然裂缝及压裂缝的空间展布。(3)加快研发高性能过钻杆测井。测井项目至少应包括常规、电成像和阵列声波等测井技术,并逐步配套元素全谱测井,其资料精度和纵向分辨率与电缆测井相一致,密度和中子测井采用小型化高产额可控中子管技术;加大核磁共振测井的小型化攻关,发展形成技术性能可匹配于电缆测井的过钻杆核磁共振测井。(4)加大研发近钻头和远探边随钻测井技术。一是测井系列配套、针对性强,发展包括自然伽马和电阻率等方位成像随钻技术,其探测点距钻头小于1m;二是方位远探边技术,径向探测距离达20~30m,方位分辨率至少为90°;三是钻头前视探测技术,可分辨钻头前方距离5m以上的地层界面或断层。

The petroleum exploration in most of the domestic petroliferous basins has entered or will step into the stage of unconventional oil and gas exploration and development.The wireline logging technologies should be promoted to meet the development trend timely and effectively.The current situation,challenges and new requirement of logging technology in China are systematically analyzed by considering the characteristics of unconventional reservoir,oil and gas reservoir and engineering conditions.Finally,development countermeasures are proposed in detail by benchmarking international leading logging technology,which are:(1)Improve the performances of conventional wireline logging tools.The high-precision,high-resolution and high-safety conventional logging tools should be developed and put into production,with vertical resolution of 5-10 cm,density logging accuracy of 0.01-0.015 g/cm3.The high-yield controllable neutron tube technology will enable the safe density and neutron logging without radioactive source.(2)Develop high-performance imaging logging technology.Firstly,focus on the technology of 2D NMR logging with short echo interval(no more than 0.2 ms),high vertical resolution(about 10 cm),high signal-to-noise ratio(more than 8),and simultaneous detection of longitudinal and transverse relaxation;Secondly,research fi ne calculation of mineral compositions and accurate determination of fl uid properties applicable for tight reservoirs,such as the full spectrum of elements,multi frequency dielectric log,downhole real-time fl uid analysis and pressure measurement tools,and horizontal well multiphase fl ow imaging logging technology;Thirdly,promote 3D acoustic logging technology with the capabilities of fi ne azimuth resolution and ultra-far detection to describe the stratigraphic structure near the borehole of horizontal well,fault system,and spatial distribution of hydraulic fractures.(3)Speed up the research on high-performance through-pipe logging tools.The logging items should include conventional logging,electric imaging logging and array acoustic logging.The element full spectrum logging should gradually be supplemented,with its data accuracy and vertical resolution consistent with those of wireline logging data.The density and neutron logging tools should adopt miniaturized,high-yield and controllable neutron tube technology.The miniaturization of NMR logging should be enhanced to develop through-pipe NMR logging with its technical performance matching with that of wireline logging.(4)Emphasize the research on near bit and far-detection edge LWD technology.First is to establish a complete LWD logging series including GR and resistivity azimuth imaging logging,with the distance of less than 1 m between the detection point and drill bit;Second is azimuth far-detection edge technology with radial detection range of 20-30 m and azimuth resolution of at least 90°;Third is the forward-looking detection technology that can distinguish the formation interface or fault more than 5 m in front of the bit.