Casing and Cement Evaluation on Drillpipe: New Tool Acquires Well Integrity Data in Parallel with Existing Drillpipe Deplyed Operations from Drilling to Plug and Abandonment

Abstract

Casing and cement evaluation logging has long been essential for the success and safety of well operations from spud all the way through to abandonment. Indeed, as the casing and subsequent cement play such a critical role in the separation of fluids and the provision of downhole pressure barriers it is essential and sometimes also a regulatory requirement to obtain such data. For example, understanding the condition of the casing, whether it is worn or corroded, and the material in the annulus behind the casing, such as cement, fluid, formation or even gas directly plays into the success or otherwise and also the safety of multiple well operations. Historically this information has only been available from wireline conveyed tools. As a consequence of this other rig operations then have to stop to allow the wireline logging. It is also true to say that over the last few decades wells have become significantly more complex, more deviated and deeper. In addition, the pressure regimes have required tighter margins increasing the risk of operations and necessitating a greater need to understand the integrity of casing and cement barriers. As the wells have become deeper, more complex and more highly deviated it is also more difficult to run wireline conveyed tools, often significantly increasing the amount of time required to run and obtain this data. In fact, it can be clearly seen that increasingly, operators have often declined to get this critical data due to the time and effort required in certain circumstances to log on wireline. This has had a significant impact in terms of non productive time associated with not understanding the condition of casing and cement in well operations such as side tracking or cut and pull operations. For those associated with drilling then there has been a huge advancement in the technology, reliability and utilization of logging while drilling technology, although this has traditionally been employed in the openhole sections and deployed only while drilling. This paper will introduce a drillpipe conveyed casing and cement evaluation tool that can be deployed in parallel with other runs in the well to improve the efficiency of operations whilst also increasing the frequency of times that this data can be acquired. Through case history we will demonstrate how operators improved efficiency, reduced rigtime and personnel on board, improved the safety of operations and reduced the risk of non-productive time by the application of this new drillpipe conveyed technology.