This case-history paper focuses on the evolution of a novel completion concept. The concept resulted from improvements in through-tubing vent-screen technology and the invention of a wireless casing collar locator (CCL) for coiled tubing (CT) operations. This completion method provides the following:

  • reduced completion costs

  • improved completion efficiency

  • extended completion life

  • reduced mechanical risk

  • improved reserve recovery rate

The invention of the wireless CT CCL was a key development that advanced this completion technique.

A new surface-modification agent (SMA) is at the core of this completion process. The SMA is a water- and oil-insoluble, resinous liquid additive that does not harden or cure under reservoir conditions. This additive is applied to proppant during the sand-control portion of the completion process to increase the cohesive forces between the proppant grains. The SMA provides the following advantages:

  • It can help increase pack permeability and porosity by up to 30%.

  • It helps control fines migration.

  • It decreases mechanical risk by helping stabilize the annular pack.

Tests have shown that using of SMA increases the critical flow velocity of the annular pack. It (1) allows the well to produce at higher rates without producing the sand from the annulus or (2) allows the operator to shorten the completion blank length at a given production flow rate, and (3) allows the length of the completion assembly to be reduced, providing flexibility that allows the completion method to be used on wells with closely stacked pay zones.

Before the development of CT CCL, operators had to use CT rigs with an electric line in the tubing to power downhole tools with perforating collar locators or gamma ray (GR) perforators. This system could triple or quadruple job costs. Wireless CCL allows accurate depth measurements with CT, making it possible to run guns and packers on CT with an existing GR CCL log as a reference. The CT CCL eliminates the need for e-line and reduces the completion time and daily spread cost. When the space limitations and the time required for repositioning the equipment for different phases of the operation are considered, the time associated with spotting equipment in offshore operations can be substantial. The CT CCL reduces completion time.

The following case histories describe economically successful jobs performed with these integrated services.

You can access this article if you purchase or spend a download.