Expandable pipeline pig assembly

An expandable pipeline pig comprising:

• (a) an elongated cylindrical body member;
• (b) a front plate member, a center portion of which is fixedly attached to a front portion of elongated cylindrical body member;
• (c) a rear plate member, a center portion of which is fixedly attached to a rear portion of elongated cylindrical body member;
• (d) a collar member slidably disposed about said elongated cylindrical body member, said collar member:
• (i) having an outer portion forming a ring about said elongated cylindrical body member;
• (e) front rib members:
• (i) having front-end portions pivotably attached to a rear side portion of said front plate member;
• and
• (ii) wherein the point of said pivotable attachments is radially equidistant about-the elongated cylindrical body member;
• (f) front strut members having front-end portions and rear-end portions:
• (i) wherein said front-end portions are pivotably attached to rear-end portions of said front rib members;
• (ii) wherein said rear-end portions are pivotably attached to outer portions of said collar member, wherein the point of said pivotable attachments is radially equidistant about said elongated cylindrical body member;
• and
• (iii) wherein said attachment points of the rear-end portions of said front strut members substantially correspond to the radial point of attachment of said front-end portions of said front rib members which are pivotably attached to said rear side portion of said front plate member;
• (g) rear rib members:
• (i) having front-end portions pivotably attached to a rear side portion of said rear-end plate;
• and
• (ii) wherein the point of said pivotable attachments is radially equidistant about the elongated cylindrical body member;
• (h) rear strut means for biasing rear-end portions of said rear rib members;
• (i) at least one bias means for moving said collar member toward the front of said elongated cylindrical body member, thereby deploying said front and rear rib members;
• (j) a front diaphragm member, wherein radial portions of said front diaphragm member are flexibly attached to said front rib members;
• (k) a rear diaphragm member, wherein radial portions of said rear diaphragm member are flexibly attached to said rear rib members;
• and
• (l) wherein said elements are so disposed such that sliding said front and rear strut members toward the front of said elongated cylindrical body member, due to expansion of said bias means, results in pivoting the rear-end portions of said front and rear rib members outward from said elongated cylindrical body member such as occurs when opening an umbrella.

A method for separating different liquids and gases in a flexible oil/gas export riser which feeds to a larger diameter rigid oil/gas export pipeline, said method comprising:

• (a) passing a first expandable pipeline pig in a retracted position into an upper portion of said export riser;
• (b) passing said first expandable pipeline pig from a lower portion of said export riser into said larger diameter rigid oil/gas export pipeline;
• (c) expanding said first expandable pipeline pig;
• wherein said first expandable pipeline pig is adapted to separate different liquids and gases;
• (d) wherein said first expandable pipeline pig comprises:
• (i) an elongated cylindrical body member, from about 20 inches to about 50 inches in length;
• (ii) a front plate member, a center portion of which is fixedly attached to a front portion of said elongated cylindrical body member;
• (iii) a rear plate member, a center portion of which is fixedly attached to a rear portion of said elongated cylindrical body member;
• (iv) a collar member slidably disposed about said elongated cylindrical body member, said collar member:
• (a) having an outer portion forming a ring about said elongated cylindrical body member;
• (v) front rib members:
• (a) having front-end portions pivotably attached to a rear side portion of said front plate member;
• and
• (b) wherein the point of said pivotable attachments is radially equidistant about the elongated cylindrical body member;
• (vi) front strut members having front-end portions and rear-end portions:
• (a) wherein said front-end portions are pivotably attached to rear-end portions of said front rib members;
• (b) wherein said rear-end portions are pivotably attached to outer portions of said collar member, wherein the point of said pivotable attachments is radially equidistant about said elongated cylindrical body member;
• and
• (c) wherein said attachment points of the rear-end portions of said front strut members substantially correspond to the radial point of attachment of said front-end portions of said front rib members which are pivotably attached to said rear side portion of said front plate member;
• (vii) rear rib members:
• (a) having front-end portions pivotably attached to a rear side portion of said rear plate member;
• and
• (b) wherein the point of said pivotable attachments is radially equidistant about the elongated cylindrical body member;
• (viii) rear strut means for biasing rear-end portions of said rear rib members;,
• (ix) at least one bias means for moving said collar member toward the front of said elongated cylindrical body member, thereby deploying said front and rear rib members;
• (x) a front diaphragm member, wherein radial portions of said front diaphragm member are flexibly attached to said front rib members;
• (xi) a rear diaphragm member, wherein radial portions of said rear diaphragm member are flexibly attached to said rear rib members;
• and
• (xii) wherein said elements are so disposed such that sliding said front and rear strut members toward the front of said elongated cylindrical body member, due to expansion of said bias means, results in pivoting the rear end portions of said front and rear rib members outward from said elongated cylindrical body member such as occurs when opening an umbrella.