JP2004037257A - Gas leak detector for intra-bedrock gas storage facility and gas leak detecting method - Google Patents

Gas leak detector for intra-bedrock gas storage facility and gas leak detecting method Download PDF

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Publication number
JP2004037257A
JP2004037257A JP2002194851A JP2002194851A JP2004037257A JP 2004037257 A JP2004037257 A JP 2004037257A JP 2002194851 A JP2002194851 A JP 2002194851A JP 2002194851 A JP2002194851 A JP 2002194851A JP 2004037257 A JP2004037257 A JP 2004037257A
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storage facility
rock
gas storage
gas
bedrock
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Inventor
Takuro Nishi
西　琢郎
Tetsuo Okuno
奥野　哲夫
Kuniichiro Miyashita
宮下　國一郎
Toshiyuki Hatta
八田　敏行
Makoto Hasegawa
長谷川　誠
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Shimizu Construction Co Ltd
Shimizu Corp
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Shimizu Construction Co Ltd
Shimizu Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas leak detector for an intra bedrock gas storage facility using a bedrock cavity, having high precision and promptly locating gas leak, and a gas leak detecting method. <P>SOLUTION: This gas leak detector 2 comprises boreholes 3, electrodes 4, and a measuring instrument 6. The intra bedrock gas storage facility 1 utilizes a cavity part in bedrock formed by digging out the bedrock 8 into a cylindrical shape, and the cavity part is filled with stored gas 5. Near the periphery of the storage facility 1, the plurality of boreholes 3 are provided so as to surround the storage facility and to extend vertically or obliquely at prescribed distances centering around the storage facility 1. The boreholes 3 are formed by boring deeper than a position where the storage facility 1 is installed and the plurality of electrodes 4 are disposed therein at prescribed intervals from hole inlets to hole bottoms. The electrodes 4 are connected to the measuring instrument 6 on the ground, and potential response is measured by the measuring instrument 6 when an electric current is passed through the bedrock 8 via the electrodes 4. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、精度が良く、早期に漏気を探知できる岩盤空洞を用いた岩盤内気体貯蔵施設の漏気検知装置、及び漏気検知方法に関する。
【０００２】
【従来の技術】
現在、都市ガスや石油ガス、発電に用いる高圧空気などを大規模に貯蔵する施設として、岩盤内に掘削した空洞を貯蔵施設として用いる方法が多く見られる。この方法は、高圧あるいは可燃性気体を大量・安全に保管し、かつ地上景観を損なわない施設として有効である。一方で、これら貯蔵ガスを長期間にわたって安全に貯蔵操業していくために、空洞周辺岩盤の漏気に対する健全性を的確に把握していくことが必要となる。
【０００３】
なかでも、空洞周辺の地下水圧によって貯蔵油及びガスを封じ込める水封式石油地下備蓄方式では、水封機能の健全性を評価するため、空洞周辺の地下水位、空洞内への湧水量、水封水供給量の変化を常時計測している。このような方法は、操業時の運転データを用いて異常を検知する方法であるため、異常の早期発見には有効である。
【０００４】
【発明が解決しようとする課題】
しかし、実際に異常が検知された際に、その異常がどの場所でどの程度の規模で発生しているかを特定するには、精度上困難である。このため、異常が検知された後、その部分の修復を効率よく行うためには、より精度の高い検知方法が求められる。
【０００５】
上記事情に鑑み、本発明は、精度が良く、早期に漏気を探知できる岩盤空洞を用いた岩盤内気体貯蔵施設の漏気検地装置、及び漏気検知方法を提供することを目的としている。
【０００６】
【課題を解決するための手段】
請求項１に記載の岩盤内気体貯蔵施設の漏気検知装置は、岩盤内に設けられた気体貯蔵施設の漏気を検知する岩盤内気体貯蔵施設の漏気検知装置であって、前記岩盤内気体貯蔵施設を中心に所定の間隔を設けて鉛直あるいは斜め方向に延在し、貯蔵施設を取り囲むように離間配置される複数のボーリング孔と、該ボーリング孔の内方で所定の間隔で複数配置された電極とにより構成されることを特徴としている。
【０００７】
請求項２に記載の岩盤内気体貯蔵施設の漏気検知方法は、岩盤内に設けられた気体貯蔵施設の漏気を検知する岩盤内気体貯蔵施設の漏気検知装置を用いた漏気検知方法であって、前記岩盤内気体貯蔵施設を中心に、所定の間隔を設けて鉛直あるいは斜め方向に延在する複数のボーリング孔を、貯蔵施設を取り囲むように離間配置するとともに、該ボーリング孔の内方で所定の間隔で電極を複数配置し、前記岩盤内気体貯蔵施設の操業前と操業開始後の両者で、前記電極を通じて岩盤内に電流を流し、測定された電位応答から比抵抗トモグラフィー手法により比抵抗値の分布状況を推定し、両者の変化量によって漏気を検知することを特徴としている。
【０００８】
請求項３に記載の岩盤内気体貯蔵施設の漏気検知方法は、前記岩盤内気体貯蔵施設の操業前と操業開始後の比抵抗値の分布状況の変化量を、操業前に対する操業開始後の比抵抗値の分布状況の変化率とし、操業前と操業開始後の比抵抗値の分布状況を相対比較とすることを特徴としている。
【０００９】
【発明の実施の形態】
以下、本発明の岩盤内気体貯蔵施設の漏気検知装置、及び漏気検知方法を、図１から図３を用いて詳述する。本実施の形態は、円筒状やサイロ状、もしくはこれらに近似した形状に掘削された岩盤空洞を気体貯蔵施設として用いた場合における、漏気検知方法と、これに用いる漏気検知装置を示すものである。
【００１０】
なお、本実施の形態で用いる岩盤内気体貯蔵施設１の漏気検知装置２は、一般に知られている比抵抗トモグラフィーによる地盤調査方法を念頭に置き、構成されている。ここで、比抵抗トモグラフィー手法は、複数のボーリング孔や地表等に多数の発信点と受信点を配置し、ボーリング孔間や地表とボーリング孔間で電流を流すことにより電位応答を計測し、逆解析手法を用いて任意の２本のボーリング孔間における比抵抗値の分布を把握することにより、岩盤の健全性等を把握する手法である。
【００１１】
図１に示すように、岩盤内気体貯蔵施設１の漏気検知装置２は、ボーリング孔３と、電極４と、計測装置６とより構成される。
前記岩盤内気体貯蔵施設１は、岩盤８を円筒状に掘削した岩盤中の空洞部を利用しており、空洞部には貯蔵ガス５が充たされている。前記岩盤内気体貯蔵施設１の外周近傍には、岩盤内気体貯蔵施設１を中心に一定の距離を設けて鉛直方向に延在するように、周方向に複数のボーリング孔３が設けられている。
【００１２】
該ボーリング孔３は、前記岩盤内気体貯蔵施設１の設置位置よりも深く削孔されており、その内方には孔口から孔底まで鉛直方向に等間隔で複数の電極４が配置されている。該電極４は、地上の計測装置６に連結されており、該計測装置６により、前記電極４を通じて地盤８中に電流を流した際の電位応答を測定する。
【００１３】
上述する岩盤内気体貯蔵施設１の漏気検知装置２を用いた漏気検知方法を以下に詳述する。
前記岩盤内気体貯蔵施設１の建設後、施設を操業する前に、該岩盤内気体貯蔵施設１の外周近傍で、周方向に所定の離間距離をもって複数のボーリング孔３を削孔し、その内方に配置された複数の電極４のうちの１つから電流を流し、他の全ての電極４における電位応答を前記計測装置６により測定する。
【００１４】
つまり、ボーリング孔３ａの第１の電極４ａから電流を流し、ボーリング孔３ａの第１以外の電極４、及び他のボーリング孔３ｂ、３ｃ、３ｄの内方に配置された全ての電極４で電位応答を測定する。次に、ボーリング孔３ａの第２の電極４ｂから電流を流し、ボーリング孔３ａの第２以外の電極４、及び他のボーリング孔３ｂ、３ｃ、３ｄの内方に配置された全ての電極４における電位応答を測定する。
【００１５】
このように、前記ボーリング孔３に設けられている電極４から電流を流し、その電位応答を電流を流している電極４以外の電極４で測定する作業を全てのボーリング孔３で終了した後、任意の２本のボーリング孔３間に挟まれた平面空間における岩盤８の比抵抗値の分布状況を、比抵抗トモグラフィー手法において一般に用いられる２孔間の逆解析手法を用いて推定する。
【００１６】
前記ボーリング孔３ａ、３ｂ、３ｃ、３ｄの２孔間に全ての組み合わせに対して上記解析を行うことにより、前記岩盤内気体貯蔵施設１周辺の岩盤８における、比抵抗値の分布状況を三次元的に把握することが可能となる。前記岩盤内気体貯蔵施設１のある断面から比抵抗値の分布状況を、図２（ａ）に示す。これらは、前記計測装置６に連結された出力装置７により出力されるが、出力装置７はモニターやプリンター等何れを用いても良い。
【００１７】
また、前記岩盤内気体貯蔵施設１周辺の岩盤８における、比抵抗値の分布状況を三次元的に把握する方法としては、上記に示す方法のみでなく、前記岩盤内気体貯蔵施設１の外周に、少なくとも３本の前記ボーリング孔３を、これらが形成する平面視三角形が岩盤内気体貯蔵施設１を内包するように配置すれば、３本のボーリング孔３間に挟まれた空間に対して、一般に用いられる３次元トモグラフィー解析を行うことによって、岩盤８の比抵抗値を３次元分布として把握することも可能である。
【００１８】
なお、３次元トモグラフィー解析は、３本以上の前記ボーリング孔３のデータを同時に扱うことができるため、複数の前記ボーリング孔３を、これらが形成する平面視多角形が岩盤内気体貯蔵施設１を内包するように配置すれば、３次元トモグラフィー解析を用いて、容易に岩盤８の比抵抗値を３次元分布として把握することが可能である。
【００１９】
ここで、岩盤８の飽和度と比抵抗値との間には、図３に示すように岩盤８の飽和度が小さいとその比抵抗値が大幅に増加する関係を有している。これは、岩盤８の比抵抗値が、岩盤８の間隙を埋める間隙水の量に左右されるためである。これを応用すると、前記岩盤内気体貯蔵施設１から、貯蔵ガス５が漏出した際には、漏出した貯蔵ガス５が岩盤８の間隙を伝わって漏れていくものと推測される。このとき、間隙を埋めていた間隙水は、漏出した貯蔵ガス５と置換されるため、岩盤８の飽和度が低下することとなり、比抵抗値は上昇する。
【００２０】
これらの特性を利用し、岩盤内気体貯蔵施設１の操業開始後、何らかの異常が検知された場合に、先に述べたものと同様の方法で比抵抗値を測定する。異常発生後の前記岩盤内気体貯蔵施設１のある断面における比抵抗値の分布状況を、図２（ｂ）に示す。これらの結果から、操業前と異常発見後の比抵抗値の変化量を算定することによって、貯蔵ガス５の漏気を検知する。
なお、これらの漏気検知方法は、岩盤内気体貯蔵施設１周辺の岩盤８における岩種や地質構造によって、比抵抗値の分布が大きくばらつくことも考えられる。
【００２１】
そこで、異常発見後の操業前に対する比抵抗値の変化率を（（１）式）に従って算出しておき、変化の程度を相対的に把握することによっても、漏気の箇所、及びその程度を特定できる。
【００２２】
変化率　＝　（（異常発見後の測定値−操業前の測定値）
／操業前の測定値）・・・・（１）式
【００２３】
このような変化率を適用する漏気検知方法は、図２（ｃ）に示すように、岩盤内気体貯蔵施設１周辺の岩盤における、漏気に起因する比抵抗値の変化を明確に把握することができる。
【００２４】
なお、岩盤内気体貯蔵施設１の異常発見後における電位応答の測定、及び比抵抗値の分布状況の把握は、異常が検知された場合にのみ行うのではなく、操業開始後に定期的に測定を行い、モニタリングシステムを構築しても良い。
【００２５】
上述する構成によれば、比抵抗トモグラフィー手法の利用を念頭に置いた漏気検知装置２を用いて、岩盤内気体貯蔵施設１の操業の前後で地盤における比抵抗値の分布状況を把握することから、両者の変化を客観的に把握することができ、漏気箇所やその程度を精度良く推定することが可能となる。
【００２６】
前記漏気検知装置２は簡略な構成で、精度良く岩盤内気体貯蔵施設１周辺の岩盤８の比抵抗値の分布状況を３次元的に把握することができ、貯蔵ガス５の漏気箇所の分布を的確に把握することが可能となる。
【００２７】
また、３本以上のボーリング孔３を、これらが形成する平面視多角形が岩盤内気体貯蔵施設１を内包するように配置し、岩盤８の比抵抗値の分布状況を３次元トモグラフィー解析を用いて、容易に３次元的に把握することが可能となり、貯蔵ガス５の漏気箇所の分布をさらに的確に把握することが可能となる。
【００２８】
前記漏気検知装置２を用いた漏気検知方法において、操業の前後における岩盤内気体貯蔵施設１周辺の岩盤８の比抵抗値の分布状況の変化を変化率として把握することにより、岩盤内気体貯蔵施設１周辺の岩盤８の岩種や地質構造等に影響されることなく、貯蔵ガスの漏気に起因する岩盤８の変化を精度良く検知することが可能となる。
【００２９】
なお、図１に示した漏気検知装置は一例であって、ボーリング孔の配置、本数、電極間隔等はこれに限ったものではなく、岩盤内気体貯蔵施設、貯蔵施設周辺の岩盤の状況等に応じて最適な配置を検討し、実施することはいうまでもない。
【００３０】
【発明の効果】
請求項１に記載の岩盤内気体貯蔵施設の漏気検知装置は、岩盤内に設けられた気体貯蔵施設の漏気を検知する岩盤内気体貯蔵施設の漏気検知装置であって、前記岩盤内気体貯蔵施設を中心に所定の間隔を設けて鉛直あるいは斜め方向に延在し、貯蔵施設を取り囲むように離間配置される複数のボーリング孔と、該ボーリング孔の内方で所定の間隔で複数配置された電極とにより構成されることから、簡略な構成で、岩盤内気体貯蔵施設の操業の前後で地盤における比抵抗値の分布状況を把握できることから、両者の変化を客観的に把握することができ、漏気箇所やその程度を精度良く推定することが可能となる。
【００３１】
請求項２に記載の岩盤内気体貯蔵施設の漏気検知方法は、岩盤内に設けられた気体貯蔵施設の漏気を検知する岩盤内気体貯蔵施設の漏気検知装置を用いた漏気検知方法であって、前記岩盤内気体貯蔵施設を中心に、所定の間隔を設けて鉛直あるいは斜め方向に延在する複数のボーリング孔を、貯蔵施設を取り囲むように離間配置するとともに、該ボーリング孔の内方で所定の間隔で電極を複数配置し、前記岩盤内気体貯蔵施設の操業前と操業開始後の両者で、前記電極を通じて岩盤内に電流を流し、測定された電位応答から比抵抗トモグラフィー手法により比抵抗値の分布状況を推定し、両者の変化量によって漏気を検知することから、精度良く岩盤内気体貯蔵施設周辺の岩盤の比抵抗値の分布状況を３次元的に把握することができ、貯蔵ガスの漏気箇所の分布を的確に把握することが可能となる。
【００３２】
また、３本以上のボーリング孔を、これらが形成する平面視多角形が岩盤内気体貯蔵施設を内包するように配置すれば、岩盤の比抵抗値の分布状況を３次元トモグラフィー解析を用いて、容易に３次元的に把握することが可能となり、貯蔵ガスの漏気箇所の分布をさらに的確に把握することが可能となる。
【００３３】
請求項３に記載の岩盤内気体貯蔵施設の漏気検知方法は、前記岩盤内気体貯蔵施設の操業前と操業開始後の比抵抗値の分布状況の変化量を、操業前に対する操業開始後の比抵抗値の分布状況の比とし、操業前と操業開始後の比抵抗値の分布状況を相対比較とすることから、岩盤内気体貯蔵施設周辺の岩盤の岩種や地質構造等に影響されることなく、貯蔵ガスの漏気に起因する岩盤の変化を精度良く検知することが可能となる。
【図面の簡単な説明】
【図１】本発明に係る岩盤内気体貯蔵施設の漏気検知装置の概略を示す図である。
【図２】本発明に係る岩盤内気体貯蔵施設周辺の比抵抗値の分布状況を示す図である。
【図３】本発明に係る岩盤の飽和度と比抵抗値との関係を示すグラフである。
【符号の説明】
１　岩盤内気体貯蔵施設
２　漏気検知装置
３　ボーリング孔
３ａ　ボーリング孔
３ｂ　ボーリング孔
３ｃ　ボーリング孔
３ｄ　ボーリング孔
４　電極
４ａ　電極
４ｂ　電極
５　貯蔵ガス
６　計測装置
７　出力装置
８　岩盤[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a leak detection device and a leak detection method for a gas storage facility in a rock using a rock cavity capable of detecting a leak at an early stage with high accuracy.
[0002]
[Prior art]
At present, as a facility for storing city gas, oil gas, high-pressure air used for power generation, and the like on a large scale, there are many methods of using a cavity excavated in a bedrock as a storage facility. This method is effective as a facility that safely stores a large amount of high-pressure or combustible gas and does not impair the landscape. On the other hand, in order to safely store and operate these stored gases for a long period of time, it is necessary to accurately grasp the soundness of the rock around the cavity against leakage.
[0003]
Above all, in the water-sealed oil underground storage system, in which stored oil and gas are confined by the groundwater pressure around the cavity, the groundwater level around the cavity, the amount of spring water into the cavity, Changes in water supply are constantly measured. Since such a method is a method of detecting an abnormality using operation data during operation, it is effective for early detection of an abnormality.
[0004]
[Problems to be solved by the invention]
However, when an abnormality is actually detected, it is difficult in terms of accuracy to specify where and on what scale the abnormality has occurred. Therefore, after an abnormality is detected, a more accurate detection method is required in order to efficiently repair that portion.
[0005]
In view of the above circumstances, an object of the present invention is to provide an air leak detection device and an air leak detection method for a gas storage facility in a rock using a rock cavity capable of detecting an air leak early with good accuracy.
[0006]
[Means for Solving the Problems]
The gas leakage detection device for a gas storage facility in a rock according to claim 1 is a gas leakage detection device for a gas storage facility in a rock that detects gas leakage from a gas storage facility provided in the rock, wherein A plurality of boring holes extending vertically or obliquely at predetermined intervals around the gas storage facility and spaced apart so as to surround the storage facility; and a plurality of boring holes arranged at predetermined intervals inside the boring holes. And characterized in that:
[0007]
The method for detecting an air leak in a gas storage facility in a rock according to claim 2 is a method for detecting an air leak in a gas storage facility in a rock which detects an air leak in a gas storage facility provided in the rock. A plurality of boring holes extending vertically or obliquely at predetermined intervals around the gas storage facility in the rock, and spaced apart from each other so as to surround the storage facility. A plurality of electrodes are arranged at predetermined intervals in the direction, and before and after the operation of the gas storage facility in the rock, an electric current is caused to flow through the electrodes in the rock, and a resistivity tomography method is used from the measured potential response. It is characterized in that the distribution state of the specific resistance value is estimated, and the air leak is detected based on the amount of change between the two.
[0008]
The method for detecting gas leakage in a gas storage facility in rock according to claim 3 is characterized in that the amount of change in the distribution state of the resistivity value before and after the operation of the gas storage facility in the rock is determined by comparing The method is characterized in that the distribution of the specific resistance value before and after the start of the operation is a relative comparison, and the distribution of the specific resistance value is a relative change.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an air leak detection device and an air leak detection method for a gas storage facility in a rock according to the present invention will be described in detail with reference to FIGS. This embodiment shows an air leak detection method and an air leak detection device used in a case where a rock cavity excavated into a cylindrical shape, a silo shape, or a shape similar thereto is used as a gas storage facility. It is.
[0010]
Note that the air leak detection device 2 of the gas storage facility 1 in the rock used in the present embodiment is configured with a ground inspection method based on generally known resistivity tomography in mind. Here, the resistivity tomography method arranges a number of transmitting points and receiving points on a plurality of boring holes or the ground surface, and measures the potential response by flowing a current between the boring holes or between the ground surface and the boring holes. This is a method for grasping the soundness of rock mass and the like by grasping the distribution of the specific resistance value between any two boring holes using an analysis technique.
[0011]
As shown in FIG. 1, the air leak detection device 2 of the gas storage facility 1 in the rock includes a boring hole 3, an electrode 4, and a measuring device 6.
The gas storage facility 1 in the rock uses a hollow portion in the rock obtained by excavating the rock 8 into a cylindrical shape, and the hollow portion is filled with the stored gas 5. In the vicinity of the outer periphery of the gas storage facility 1 in the rock, a plurality of boring holes 3 are provided in the circumferential direction so as to extend in the vertical direction at a fixed distance from the gas storage facility 1 in the rock. .
[0012]
The boring hole 3 is drilled deeper than the installation position of the gas storage facility 1 in the rock, and a plurality of electrodes 4 are arranged at equal intervals in the vertical direction from the hole opening to the hole bottom. I have. The electrode 4 is connected to a measuring device 6 on the ground, and the measuring device 6 measures a potential response when a current flows into the ground 8 through the electrode 4.
[0013]
The leak detection method using the above-described leak detection device 2 of the gas storage facility 1 in the rock will be described in detail below.
After the construction of the gas storage facility 1 in the bedrock, before the facility is operated, a plurality of boreholes 3 are drilled at a predetermined circumferential distance in the vicinity of the outer periphery of the gas storage facility 1 in the bedrock. A current is caused to flow from one of the plurality of electrodes 4 arranged on the other side, and the potential response at all other electrodes 4 is measured by the measuring device 6.
[0014]
That is, a current flows from the first electrode 4a of the boring hole 3a, and the potential is applied to the electrodes 4 other than the first electrode 4 of the boring hole 3a and all the electrodes 4 arranged inside the other boring holes 3b, 3c, and 3d. Measure the response. Next, a current is caused to flow from the second electrode 4b of the boring hole 3a, and the current is applied to all the electrodes 4 disposed inside the other boring holes 3b, 3c, and 3d of the boring hole 3a. Measure the potential response.
[0015]
As described above, after the operation of flowing a current from the electrode 4 provided in the boring hole 3 and measuring the potential response with the electrodes 4 other than the electrode 4 that is flowing the current is completed in all the boring holes 3, The distribution state of the resistivity value of the rock 8 in the plane space sandwiched between any two boring holes 3 is estimated using an inverse analysis method between the two holes that is generally used in the resistivity tomography method.
[0016]
By performing the above-described analysis for all combinations between the two boreholes 3a, 3b, 3c, and 3d, the distribution state of the specific resistance value in the rock 8 around the gas storage facility 1 in the rock can be three-dimensionally analyzed. It becomes possible to grasp it. FIG. 2A shows a distribution state of the specific resistance value from a certain cross section of the gas storage facility 1 in the rock. These are output by an output device 7 connected to the measuring device 6, but the output device 7 may be a monitor or a printer.
[0017]
As a method of three-dimensionally grasping the distribution state of the specific resistance value in the rock 8 around the gas storage facility 1 in the rock, not only the method described above but also the outer periphery of the gas storage facility 1 in the rock. If at least three of the boring holes 3 are arranged such that the triangle formed in a plan view includes the gas storage facility 1 in the rock, the space between the three boring holes 3 is By performing a generally used three-dimensional tomography analysis, it is possible to grasp the resistivity value of the rock 8 as a three-dimensional distribution.
[0018]
Since the three-dimensional tomography analysis can simultaneously handle data of three or more of the boring holes 3, a plurality of the boring holes 3 are formed by a polygon in a plan view to form the gas storage facility 1 in the rock. If they are arranged so as to include them, it is possible to easily grasp the specific resistance value of the rock 8 as a three-dimensional distribution using three-dimensional tomographic analysis.
[0019]
Here, there is a relationship between the degree of saturation of the rock 8 and the specific resistance value, as shown in FIG. 3, when the degree of saturation of the rock 8 is small, the specific resistance greatly increases. This is because the specific resistance value of the rock 8 depends on the amount of pore water that fills the gap between the rocks 8. Applying this, when the storage gas 5 leaks from the gas storage facility 1 in the rock, it is presumed that the leaked storage gas 5 leaks along the gap of the rock 8. At this time, the pore water filling the gap is replaced with the leaked storage gas 5, so that the degree of saturation of the rock 8 decreases, and the specific resistance increases.
[0020]
Utilizing these characteristics, if any abnormality is detected after the start of operation of the gas storage facility 1 in the rock, the specific resistance value is measured by the same method as described above. FIG. 2B shows a distribution state of the specific resistance value in a cross section of the gas storage facility 1 in the rock after the occurrence of the abnormality. From these results, the leakage of the stored gas 5 is detected by calculating the amount of change in the specific resistance value before the operation and after the abnormality is found.
It should be noted that in these leak detection methods, the distribution of the specific resistance value may greatly vary depending on the rock type and the geological structure of the rock 8 around the gas storage facility 1 in the rock.
[0021]
Therefore, the rate of change of the specific resistance value before the operation after the abnormality is found is calculated in accordance with (Equation (1)), and the location of the leak and the degree of the leak can be determined by relatively grasping the degree of change. Can be identified.
[0022]
Rate of change = ((measured value after abnormality detection-measured value before operation)
/ Measured value before operation) (1) formula
As shown in FIG. 2 (c), the air leak detection method using such a change rate clearly grasps a change in the resistivity value caused by air leak in the rock around the gas storage facility 1 in the rock. be able to.
[0024]
In addition, the measurement of the potential response and the distribution of the specific resistance value after the discovery of the abnormality in the gas storage facility 1 in the bedrock are performed not only when the abnormality is detected but also periodically after the start of the operation. And a monitoring system may be constructed.
[0025]
According to the configuration described above, the distribution state of the resistivity value on the ground before and after the operation of the gas storage facility 1 in the rock is grasped by using the leak detection device 2 with the use of the resistivity tomography method in mind. Thus, it is possible to objectively grasp the change between the two, and it is possible to accurately estimate the location of the leak and its degree.
[0026]
The leak detection device 2 has a simple configuration, and can accurately and three-dimensionally grasp the distribution state of the specific resistance value of the rock 8 around the gas storage facility 1 in the rock. The distribution can be accurately grasped.
[0027]
In addition, three or more boring holes 3 are arranged such that the polygon formed in a plan view includes the gas storage facility 1 in the rock, and the distribution state of the resistivity value of the rock 8 is determined by three-dimensional tomographic analysis. Therefore, it is possible to easily three-dimensionally grasp, and it is possible to more accurately grasp the distribution of the leaked portion of the stored gas 5.
[0028]
In the air leak detection method using the air leak detection device 2, the change in the distribution state of the specific resistance value of the rock 8 around the gas storage facility 1 in the rock before and after the operation is grasped as a rate of change, whereby the gas in the rock is detected. It is possible to accurately detect a change in the bedrock 8 caused by the leakage of the stored gas without being affected by the rock type, the geological structure, and the like of the bedrock 8 around the storage facility 1.
[0029]
The air leak detection device shown in FIG. 1 is an example, and the arrangement, the number, and the electrode interval of the boring holes are not limited to these, and the gas storage facility in the rock, the state of the rock around the storage facility, etc. It goes without saying that the optimum arrangement is examined and implemented according to the requirements.
[0030]
【The invention's effect】
The gas leakage detection device for a gas storage facility in a rock according to claim 1 is a gas leakage detection device for a gas storage facility in a rock that detects gas leakage from a gas storage facility provided in the rock, wherein A plurality of boring holes extending vertically or obliquely at predetermined intervals around the gas storage facility and spaced apart so as to surround the storage facility; and a plurality of boring holes arranged at predetermined intervals inside the boring holes. With the simple configuration, it is possible to grasp the distribution of the resistivity value on the ground before and after the operation of the gas storage facility in the rock, so that it is possible to objectively grasp the change of both. It is possible to accurately estimate the leak location and its degree.
[0031]
The method for detecting an air leak in a gas storage facility in a rock according to claim 2 is a method for detecting an air leak in a gas storage facility in a rock which detects an air leak in a gas storage facility provided in the rock. A plurality of boring holes extending vertically or obliquely at predetermined intervals around the gas storage facility in the rock, and spaced apart so as to surround the storage facility. A plurality of electrodes are arranged at predetermined intervals in the direction, and before and after the operation of the gas storage facility in the rock, an electric current is caused to flow through the electrodes in the rock, and a resistivity tomography method is used from the measured potential response. By estimating the distribution of the resistivity and detecting the air leak based on the change in both, the distribution of the resistivity of the rock around the gas storage facility in the rock can be accurately grasped three-dimensionally. , Storage gas It is possible to understand the distribution of the air leakage point accurately.
[0032]
In addition, if three or more boreholes are arranged such that the polygon formed in a plan view includes the gas storage facility in the rock, the distribution of the resistivity value of the rock can be analyzed using three-dimensional tomographic analysis. It is possible to easily grasp three-dimensionally, and it is possible to more accurately grasp the distribution of the leakage points of the stored gas.
[0033]
The method for detecting gas leakage in a gas storage facility in rock according to claim 3 is characterized in that the amount of change in the distribution state of the resistivity value before and after the operation of the gas storage facility in the rock is determined by comparing Because the relative resistivity distribution before and after the start of operation is a relative comparison of the distribution of resistivity, it is affected by the rock type and geological structure of the rock around the gas storage facility in the rock. Without this, it is possible to accurately detect a change in the bedrock caused by the leakage of the stored gas.
[Brief description of the drawings]
FIG. 1 is a view schematically showing an air leak detection device for a gas storage facility in rock according to the present invention.
FIG. 2 is a diagram showing a distribution state of a specific resistance value around a gas storage facility in rock according to the present invention.
FIG. 3 is a graph showing the relationship between the degree of saturation and the specific resistance of the rock according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Gas storage facility in rock 2 Gas leak detection device 3 Boring hole 3a Boring hole 3b Boring hole 3c Boring hole 3d Boring hole 4 Electrode 4a Electrode 4b Electrode 5 Storage gas 6 Measuring device 7 Output device 8 Rock

Claims (3)

岩盤内に設けられた気体貯蔵施設の漏気を検知する岩盤内気体貯蔵施設の漏気検知装置であって、
前記岩盤内気体貯蔵施設を中心に所定の間隔を設けて鉛直あるいは斜め方向に延在し、貯蔵施設を取り囲むように離間配置される複数のボーリング孔と、
該ボーリング孔の内方で所定の間隔で複数配置された電極とにより構成されることを特徴とする岩盤内気体貯蔵施設の漏気検知装置。An air leak detection device for a gas storage facility in a rock that detects leaks in a gas storage facility provided in a rock,
A plurality of boring holes extending vertically or obliquely at predetermined intervals around the gas storage facility in the rock, and spaced apart so as to surround the storage facility;
An air leakage detection device for a gas storage facility in a rock, comprising a plurality of electrodes arranged at predetermined intervals inside the borehole. 岩盤内に設けられた気体貯蔵施設の漏気を検知する岩盤内気体貯蔵施設の漏気検知装置を用いた漏気検知方法であって、
前記岩盤内気体貯蔵施設を中心に、所定の間隔を設けて鉛直あるいは斜め方向に延在する複数のボーリング孔を、貯蔵施設を取り囲むように離間配置するとともに、該ボーリング孔の内方で所定の間隔で電極を複数配置し、
前記岩盤内気体貯蔵施設の操業前と操業開始後の両者で、前記電極を通じて岩盤内に電流を流し、測定された電位応答から比抵抗トモグラフィー手法により比抵抗値の分布状況を推定し、両者の変化量によって漏気を検知することを特徴とする岩盤内気体貯蔵施設の漏気検知方法。An air leak detection method using an air leak detection device of a gas storage facility in a rock for detecting air leak of a gas storage facility provided in a rock,
A plurality of boring holes extending vertically or obliquely at predetermined intervals around the gas storage facility in the rock are spaced apart so as to surround the storage facility, and a predetermined number of holes are provided inside the boring holes. Arrange multiple electrodes at intervals,
Before and after the operation of the gas storage facility in the rock, a current is passed through the rock through the electrode, and the distribution of the resistivity is estimated from the measured potential response by the resistivity tomography method. A method for detecting gas leakage in a gas storage facility in rock, wherein the method detects a gas leak based on a change amount. 請求項２に記載の岩盤内気体貯蔵施設の漏気検知方法において、
前記岩盤内気体貯蔵施設の操業前と操業開始後の比抵抗値の分布状況の変化量を、操業前に対する操業開始後の比抵抗値の分布状況の変化率とし、操業前と操業開始後の比抵抗値の分布状況を相対比較とすることを特徴とする岩盤内気体貯蔵施設の漏気検知方法。In the method for detecting gas leakage in a gas storage facility in rocks according to claim 2,
The amount of change in the distribution of the resistivity before and after the start of operation of the gas storage facility in the bedrock is defined as the rate of change in the distribution of the resistivity after the start compared to before the operation, and before and after the start of the operation. A method for detecting air leaks in a gas storage facility in a rock mass, wherein a relative resistance value distribution state is compared.
JP2002194851A 2002-07-03 2002-07-03 Gas leak detector for intra-bedrock gas storage facility and gas leak detecting method Withdrawn JP2004037257A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008032406A (en) * 2006-07-26 2008-02-14 Taisei Corp Method of searching low water pressure part
US7606520B2 (en) 2006-11-06 2009-10-20 Lexmark International Inc. Shutter for a toner cartridge for use with an image forming device
CN101776512A (en) * 2010-02-11 2010-07-14 桂林穿孔公司 Hydraulic jackdrill reliable test-bed
CN113155388A (en) * 2021-04-26 2021-07-23 常州大学 Salt rock gas reservoir takes intermediate layer chamber wall vibrations deformation simulation experiment device under fault effect

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008032406A (en) * 2006-07-26 2008-02-14 Taisei Corp Method of searching low water pressure part
JP4686416B2 (en) * 2006-07-26 2011-05-25 大成建設株式会社 Exploration method for water pressure drop
US7606520B2 (en) 2006-11-06 2009-10-20 Lexmark International Inc. Shutter for a toner cartridge for use with an image forming device
CN101776512A (en) * 2010-02-11 2010-07-14 桂林穿孔公司 Hydraulic jackdrill reliable test-bed
CN113155388A (en) * 2021-04-26 2021-07-23 常州大学 Salt rock gas reservoir takes intermediate layer chamber wall vibrations deformation simulation experiment device under fault effect

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