公开(公告)号：US3914603A

公开(公告)日：1975-10-21

申请号：US42536773

申请日：1973-12-17

Applicant: TEXACO INC

Inventor： PAAP HANS J ,  PITTS JR ROBERT W

IPC: G01V5/04 ,  E21B49/00 ,  G01V5/10 ,  G01V5/00

CPC classification number: G01V5/105 ,  E21B49/00 ,  G01V5/102 ,  G01V5/104

Abstract: A well logging system in which a modulated high energy neutron source is utilized in a well bore to develop an intensity modulated cloud of thermal neutrons as a function of time in the surrounding media. The phase angle of the thermal neutrons is determined relative to the generated high energy neutrons from the neutron source. The formation thermal neutron decay time or neutron lifetime which is a function of type of formation materials, is derived from the phase angle measurement. Electronic systems are provided for computing formation phase angle measurements of thermal neutrons from neutron and gamma ray counts made as a function of time and which are detected by a downhole logging tool. A recording, as a function of depth, is made of the thermal neutron decay time or neutron lifetime values and/or the related thermal neutron macroscopic capture crosssection values.

Abstract translation: 测井系统，其中在井眼中利用调制的高能中子源，以在周围介质中产生作为时间的函数的热中子强度调制云。 相对于从中子源产生的高能中子，确定热中子的相位角。 形成热中子衰减时间或中子寿命是形成材料类型的函数，是从相位角测量得出的。 提供电子系统，用于计算作为时间的函数的中子和伽马射线计数的热中子的相位角测量，并由井下测井工具检测。 作为深度的函数的记录由热中子衰变时间或中子寿命值和/或相关的热中子宏观捕获截面值构成。

公开(公告)号：US3088068A

公开(公告)日：1963-04-30

申请号：US445660

申请日：1960-01-25

Applicant: TEXACO INC

Inventor： HALL JR HUGH E ,  PITTS JR ROBERT W

IPC: E21B47/09 ,  G01V3/26

CPC classification number: G01V3/26 ,  E21B47/0905

公开(公告)号：US3930152A

公开(公告)日：1975-12-30

申请号：US48933574

申请日：1974-07-17

Applicant: TEXACO INC

Inventor： PITTS JR ROBERT W

IPC: G01V5/10 ,  G01T1/16

CPC classification number: G01V5/108 ,  G01V5/102

Abstract: A system is disclosed for measuring indications of the thermal neutron lifetime of earth materials in the vicinity of a well borehole. A harmonically intensity modulated source of fast neutrons is used to irradiate the earth formations in the vicinity of a borehole with fast neutrons at three different intensity modulation frequencies. Intensity modulated clouds of thermal neutrons at each of the three modulation frequencies are detected by a single spaced detector. The tangent of phase shift of the thermal neutron intensity with respect to the fast neutron population intensity is measured at each of the three frequencies. These measurements may be appropriately combined to derive the thermal neutron lifetime of earth materials in the vicinity of the borehole.

Abstract translation: 公开了一种用于测量井眼附近的土料的热中子寿命指示的系统。 使用谐波强度调制的快中子源，以三个不同的强度调制频率对具有快中子的钻孔附近的地层进行照射。 在三个调制频率中的每一个处的热中子的强度调制云被单个间隔的检测器检测。 在三个频率的每个频率处测量热中子强度相对于快中子群体强度的相移的切线。 可以适当地组合这些测量结果以导出钻孔附近的土料的热中子寿命。