lithotarge

Lithotarge Foam Injection

In this form of preservation, as in any other, the handling methods remain critical. The core must be supported by cradles, which will ensure that the liner with core is not flexed and can be lowered safely.

The cradles must allow delivery of the core to a saw which will cut through core and liner with one movement while supporting them.

The core is placed on the stands for drainage. At this stage the core is inspected for integrity and notes taken on lithology, annular space and availablity.

Photographs are taken, if required, to illustrate any significant points of fracturing, flushing etc. At this point correlating the data in hand a decision is reached on the position and number of holes to be drilled in the section of liner containing the core.

The holes are drilled to allow for injection of the foam and to permit expulsion of any remaining drilling mud, which is pushed out ahead of the foam expansion. The foam expands into the voids and down the annulus encapsulating the core in a cushion of foam, retaining the core integrity in its position within the liner. The foam sets very quickly and is non-invasive and non-absorbent. The foam is a closed cell foam, which retains a small overburden pressure on the core.

The liner sections are placed into a polythene tubing and preserved in boxes or preferably can be packaged in crates.

They are again encapsulated in foam to allow for transportation to the laboratories without chilling or freezing.

In the laboratory an inspection window can be cut in the liner and the foam peeled from the core surface. This allows for inspection and orientation of the core without cutting. Photographs can be taken using white and ultraviolet light and an analysis program designed to fully suit the recovered core.

Lithotarge foam injection core stabilisation method was developed and enhanced by research into the effects of using different types and densities of foam.

Variation of techniques for injection and the associated pressure profiles created on the core surfaces were established. From this data and the previous field tests we were able to supply a service which could guarantee that core intergrity could be maintained. The core could now be securely packaged and shipped across continents without freezing, reaching the laboratory in the same status as received at the surface on the well site.

The core handling methods are critical if core integrity is to be retained.

To this end, we offer the additional/inclusive services of supervision of the core handling. A written report with photographs and recommendations is available where necessary. This type of independant control gives the client an unbiased assessment of the problems and solutions. This constructively leads to a superior product which could also ultimately produce significant financial and timesavings.