{"id":987737,"date":"2026-04-29T10:19:50","date_gmt":"2026-04-29T10:19:50","guid":{"rendered":"https:\/\/david.midstar.com.sa\/?page_id=987737"},"modified":"2026-06-04T13:49:18","modified_gmt":"2026-06-04T13:49:18","slug":"maximum-minimum-offset-3d","status":"publish","type":"page","link":"https:\/\/david.midstar.com.sa\/?page_id=987737","title":{"rendered":"Maximum Minimum Offset ( 3D )"},"content":{"rendered":"\t\t
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\r\n 3D Patch Geometry Design Briefing<\/span>\r\n

Mechanics of the Maximum Minimum Offset (LMos<\/sub>) in 3D Design<\/h1>\r\n

\r\n An advanced geometric analysis focusing on shallow reflection coverage preservation, line-spacing configuration limits, and the elimination of near-trace data holes.\r\n <\/p>\r\n <\/div>\r\n\r\n

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1. Defining the Maximum Minimum Offset ($LM_{os}$)<\/h2>\r\n

\r\n While the *Maximum Offset* dictates the deepest layers a survey can map, the **Maximum Minimum Offset**\u2014frequently designated as **$LM_{os}$** (Largest Minimum Offset)\u2014establishes the exact opposite: it defines the shallowest horizon your survey can successfully illuminate. \r\n <\/p>\r\n

\r\n In a perfect 2D linear seismic survey, every source station has a receiver right next to it, providing an absolute minimum offset close to zero. However, in a 3D layout, parallel receiver tracking cables are separated by a distinct **Receiver Line Spacing ($RLS$)**. When a source is discharged directly in the center of the gap between two widely spaced receiver lines, the distance to the nearest active geophone array can be quite substantial. The single widest gap found anywhere inside your active geophone tracking patch dictates your overall $LM_{os}$.\r\n <\/p>\r\n <\/div>\r\n\r\n

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2. Visualizing the Mid-Patch Near-Trace Gap<\/h2>\r\n

\r\n The chart below models a cross-section of a standard 3D patch grid. Notice how placing a source vibration midway between your receiver line spans creates an initial tracking blind zone, pushing the shallowest reflection point further down.\r\n <\/p>\r\n\r\n

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RL1<\/div>\r\n Receiver Line A<\/span>\r\n <\/div>\r\n\r\n
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S<\/div>\r\n Mid-Point Shot<\/span>\r\n <\/div>\r\n\r\n
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RL2<\/div>\r\n Receiver Line B<\/span>\r\n <\/div>\r\n \r\n
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\u2190 LMos<\/sub> Vector \u2192<\/div>\r\n
\u2190 LMos<\/sub> Vector \u2192<\/div>\r\n
Total Receiver Line Spacing (RLS)<\/div>\r\n <\/div>\r\n\r\n
\r\n Shallow Reflector Blind Spot (No Near-Traces Recorded)<\/span>\r\n \r\n \r\n \r\n \r\n <\/svg>\r\n <\/div>\r\n
Figure 1: Geometric Origin of the Largest Minimum Offset ($LM_{os}$) and Resulting Shallow Tracking Void<\/div>\r\n <\/div>\r\n <\/div>\r\n\r\n
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3. The Shallow Muting and Velocity Constraint<\/h2>\r\n

\r\n During seismic data processing, wide-angle arrivals coming from far offsets stretch distortively and break down. This distortion requires processors to apply an absolute data filter known as a **Shallow Mute**. The shallow mute discards all long-offset data points from your upper time sections, meaning your shallowest horizons must rely exclusively on short-offset (near) traces to align their structures.\r\n <\/p>\r\n

\r\n If your 3D survey lines are laid out too far apart, the resulting $LM_{os}$ becomes larger than the depth of your shallow target ($LM_{os} > Depth_{shallow}$). Once the shallow mute removes the distorted far traces, **zero data traces are left** within the inner bins. This results in a complete imaging hole, meaning key shallow layers, seal boundaries, and hazard zones disappear from your final volume.\r\n <\/p>\r\n <\/div>\r\n\r\n

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4. Architectural Rules for 3D Geometry Selection<\/h2>\r\n

\r\n To guarantee clean, continuous structural mapping from shallow targets down to deeper reservoirs, survey design teams balance the line spacing using these parameters:\r\n <\/p>\r\n \r\n

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\r\n The Diagonal Bound Criterion<\/strong>\r\n In standard orthogonal 3D designs, the $LM_{os}$ is mathematically equal to the hypotenuse corner distance across a line grid unit: $\\sqrt{RLS^2 + SLS^2}$. To maintain clean shallow resolution, this diagonal value should never exceed the depth of the highest targeted structural layer.<\/span>\r\n <\/div>\r\n
\r\n The Line Spacing Adjustment Strategy<\/strong>\r\n If initial planning shows that the $LM_{os}$ is too large, field designers cannot simply adjust individual station intervals. Instead, they must narrow the space between the tracking lines themselves (reducing the receiver or source line spacing). This adjustment tightens your near-trace coverage and secures a continuous, high-fidelity stack across all depth levels.<\/span>\r\n <\/div>\r\n <\/div>\r\n <\/div>\r\n\r\n <\/div>\r\n\r\n<\/div>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"

3D Patch Geometry Design Briefing Mechanics of the Maximum Minimum Offset (LMos) in 3D Design An advanced geometric analysis focusing on shallow reflection coverage preservation, line-spacing configuration limits, and the elimination of near-trace data holes. 1. Defining the Maximum Minimum Offset ($LM_{os}$) While the *Maximum Offset* dictates the deepest layers a survey can map, the…<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"elementor_header_footer","meta":{"footnotes":""},"class_list":["post-987737","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/david.midstar.com.sa\/index.php?rest_route=\/wp\/v2\/pages\/987737","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/david.midstar.com.sa\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/david.midstar.com.sa\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/david.midstar.com.sa\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/david.midstar.com.sa\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=987737"}],"version-history":[{"count":4,"href":"https:\/\/david.midstar.com.sa\/index.php?rest_route=\/wp\/v2\/pages\/987737\/revisions"}],"predecessor-version":[{"id":987857,"href":"https:\/\/david.midstar.com.sa\/index.php?rest_route=\/wp\/v2\/pages\/987737\/revisions\/987857"}],"wp:attachment":[{"href":"https:\/\/david.midstar.com.sa\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=987737"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}