CN2351551Y

CN2351551Y - High-resolution double-lateral log equipment electrode system

Info

Publication number: CN2351551Y
Application number: CN98232431U
Authority: CN
Inventors: 阮韩光; 黄继贞; 朱军
Original assignee: XIAN PETROLEUM PROSPECTING INSTRUMENT GENERAL FACTORY
Current assignee: XIAN PETROLEUM PROSPECTING INSTRUMENT GENERAL FACTORY
Priority date: 1998-01-20
Filing date: 1998-01-20
Publication date: 1999-12-01
Anticipated expiration: 2008-01-20

Abstract

The utility model provides a double-lateral electrode system with high resolution for logging equipment. The existing metal ring called A0 is replaced by three metal rings called A01', A00 and A01 as a main electrode, and other electrodes are not changed. When the three metal rings called A01', A00 and A01 are regarded as the main electrode, the depth of detection can remain unchanged at the time of double-lateral well detection. When the A00 is regarded as an independent electrode, the stratum resolution of the double-lateral well detection can reach 0.2 to 0.3 meter. The utility model can be suitable for the double-lateral well detection for the thin stratum needing resolution.

Description

High-resolution dual laterolog equipment electrode system

The utility model belongs to the oil well logging field, particularly a kind of device that is used for dual laterolog.

Existing dual laterolog equipment electrode system is that cover constitutes with a plurality of different in width and with the metal ring that different interval is arranged on the insulating carrier of elongated cylindrical, metal ring is called electrode again, and during oil reservoir logging, electrode system is inserted into the down-hole, specifically constitute with reference to Fig. 1, the center is A ₀Electrode is with A ₀Electrode is that axis of symmetry is upwards arranged four electrodes, is respectively M ₁', M ₂', A ₁', A ₂', arrange four electrodes downwards, be respectively M ₁, M ₂, A ₁, A ₂A ₀Be called main electrode, A ₁', A ₂', A ₁, A ₂Being called bucking electrode, all is current electrode, and M ₁', M ₂', M ₁, M ₂It is monitor electrode.The vertical resolution that aforementioned existing dual laterolog equipment is showed when logging well is roughly 00 ' (M ₁With M ₂Between mid point be called 0), M ₁' with M ₂' between mid point be called 0 ', generally be about about 0.7 meter.To some thin strates, such vertical resolution is not enough, and existing bilateral is very limited to improving on the vertical resolution, its reason be to improve vertical resolution need be with main electrode electric current I A ₀Width reduce, be about to 00 ' distance and reduce, but 00 ' reduce to be very limited, reason has two, the one, if with A ₁', A ₂', A ₁, A ₂Size reduce in proportion, then the investigation depth of entire electrode system is approximate descends in proportion, thereby has sacrificed investigation depth; The 2nd, if A ₁', A ₂', A ₁, A ₂Size remain unchanged, investigation depth can not descend, but the influence of well and country rock becomes very complicated, data is used very difficult.

The purpose of this utility model is to provide a kind of high-resolution dual laterolog equipment electrode system, after the use kind electrode system, can guarantee that dual laterolog equipment has original enough investigation depths, can improve the stratigraphic resolution of this dual laterolog equipment again.

The utility model is realized as follows.

High-resolution dual laterolog equipment electrode system of the present utility model is by the insulating carrier of elongated cylindrical and be placed in the metal ring that is called electrode that a plurality of different in width on the aforementioned dielectric carrier arrange with different interval and constitute, and is that axis of symmetry makes the M that sequentially is arranged in from bottom to up on the main electrode with the metal ring that is called main electrode in central authorities ₁', M ₂', A ₁', A ₂' four metal rings and from top to down order are arranged in the M under the main electrode ₁, M ₂, A ₁, A ₂Four metal ring symmetric arrays, wherein main electrode is called A by three ₀₁', A ₀₀, A ₀₁The metal ring that certain intervals is arranged mutually constitute.

The utility model has following advantage.

Keeping original bilateral under condition of work, with main electrode A ₀Widen and be divided into three parts, the centre is A ₀₀, two parts are respectively A up and down ₀₁' and A ₀₁, A ₀₀With A ₀₁', A ₀₁Spaced apart, A ₀₁' and A ₀₁Between can power respectively or short circuit connects, during well logging, keep A ₀₀, A ₀₁', A ₀₁Three electrode equipotentials.Like this, with A ₀₀, A ₀₁', A ₀₁Three electrodes lump together when regarding an electrode as, with original bilateral to identical, can realize original bilateral to measurement.If measure A more respectively ₀₀Electrode IA _00D(dark side direction), IA _00S(shallow side direction), same available bilateral calculates the measurement apparent resistivity to similar formula.Because A ₀₀Electrode is narrower, so vertical resolution is very strong, can effectively differentiate 0.2～0.3 meter stratum.Again because A ₀₀Electric current I A _00D(or IA _00S) be subjected to A ₀₁The electric current I A of ' electrode _01D(or IA _01S) and A ₀₁The electric current I A of electrode _01D(or IA _01S) focussing force, only enter the stratum and more just scatter the depths, thereby can detect the more resistivity of deep formation, can not be lower than at least original bilateral to investigation depth, in addition, shoulder effect and wellbore effect also will less than original bilateral to.

Description of drawings.

Fig. 1 is the overall formation schematic diagram of the dual laterolog equipment electrode system of prior art of the present utility model.

Fig. 2 is the overall formation schematic diagram of high-resolution dual laterolog equipment electrode system of the present utility model.

Below in conjunction with accompanying drawing in detail embodiment of the present utility model is described in detail.With reference to Fig. 2, cover is loaded onto the metal ring as electrode, metal ring A on the insulating carrier 1 of elongated cylindrical ₀₀In the central authorities of insulating carrier 1, metal ring A ₀₀On be metal ring A ₀₁', metal ring A ₀₁At A ₀₀Under, A ₀₁', A ₀₀, A ₀₁The three constitutes main electrode, then upwards arranges four metal M ₁', M ₂', A ₁' and A ₂', be that axis of symmetry is arranged M downwards with the main electrode ₁, M ₂, A ₁, A ₂Totally four metal rings, wherein M ₁', M ₂', M ₁, M ₂, be monitor electrode, A ₁', A ₂', A ₁, A ₂Be bucking electrode.

Claims

1. high-resolution dual laterolog equipment electrode system, by the insulating carrier 1 of elongated cylindrical and be placed in the metal ring that is called electrode that a plurality of different in width on the aforementioned dielectric carrier 1 arrange with different interval and constitute, be that axis of symmetry makes the M that sequentially is arranged in from bottom to up on the main electrode with the metal ring that is called main electrode in central authorities ₁', M ₂' A ₁', A ₂', four metal rings and from top to down order be arranged in the M under the main electrode ₁, M ₂, A ₁, A ₂Four metal ring symmetric arrays is characterized in that being called the metal ring of main electrode by being called A ₀₁', A ₀₀, A ₀₁Three metal rings that certain intervals is arranged mutually constitute.