Drilling horizontal wells has become the more commonplace in many Saudi Aramco fields. Recent advances in drilling and completion practices enable the drilling of more complex wells with various types and shapes such as extended reach wells, bi-laterals and multi-laterals for providing maximum reservoir contact. These complex wells impose great challenges with respect to rigless well interventions. One of the initial well interventions, which follow drilling completion, is acid stimulation to remove formation damage. The challenges raised because of well complexity include accessing the laterals, reaching the end of each lateral and properly distributing treatment fluids over entire horizontal sections.
Effective rigless interventions in these challenging wells have limitations and technologies are still evolving. Deployment of tools and fluids downhole is no more possible through conventional coiled tubing applications. New techniques have been developed to assist coiled tubing (CT) to access laterals and extend their reach. In addition, recent advancement of CT bottom-hole assembly (BHA) allows combining services of more than one function such as deploying tools and fluids and at the same time acquiring vital downhole data.
The fiber optic enabled CT (FOCT) provides combined services of data acquiring on real time and running crucial CT technology tools. By the virtue of the optical fiber, distributed measurements could be made available to obtain temperature profiles. The temperature surveys allow evaluating flow distribution through temperature responses; hence, optimizing acid stimulation. FOCT with a flow-through BHA coupled with smart combination of technology tools such as a multi-lateral tool (MLT) and a mechanical drag reducer tool provides integrated services.
This paper highlights the first ever worldwide combination of technology tools via FOCT for acquiring downhole data on real time and technology tools for accessing and extending the reach of the CT for stimulating a tri-lateral oil producer in a major carbonate reservoir in Saudi Arabia. This combination has resulted in successful acid stimulation of all three laterals. The paper also discusses in detail the application of distributed temperatures for placing treatment fluids and experience gained.