Unique Statoil reservoir validates accuracy of new technology

Overview 

In four deepwater wells offshore East Africa, Statoil used Halliburton’s new ICE CoreSM fluid analysis service to accurately characterize fluids downhole. (ICE stands for Integrated Computational Element.) The reservoirs all contained dry gas. Statoil tested Halliburton’s new ICE Core technology against laboratory analysis of the fluids from each well. ICE Core technology recognizes the chemical fingerprints of various fluids when a light shines through them. Each ICE Core sensor detects the fingerprint of a specific analyte and calculates its proportion of the total fluid stream. In each well, ICE Core technology accurately predicted the results of laboratory analysis. Statoil’s Leading Advisor of Geology Formation Evaluation & Geo Operations, Kåre Otto Eriksen, describes it as a “game-changing” technology for downhole fluid scanning when additional ICE Core sensors are available to detect other critical fluid components.

Challenge  

Downhole spectroscopy has long been used during pumpout tests downhole. It is good at telling when a reservoir fluid is pure enough to begin sampling. However, because band width only extends to about 2100 nm, it is not very good at characterizing fluids and their proportions in the stream. All sampling tools have limited collection capacity. In very long and deep wells, enough capacity may not exist to sample every part of a well without making additional runs. This presents a dilemma: escalate costs or uncertainty. The risks of making bad assumptions are enormous. Laboratory analysis can take months or even years. During that time, samples may be lost, contaminated or experience phase change. The cost of bringing a rig back to the site to collect more samples would be prohibitive, but alternatives could be even more costly – bad field planning.

Solution 

ICE Core sensors have a much wider bandwidth – to about 5500 nm. This is where the differences between reservoir fluids become most apparent. Plus, ICE Core sensors each use 100% of the available light instead of splitting up the spectrum. Result: much greater fluid analysis accuracy. ICE Core technology is available as part of Halliburton’s proven Reservoir Description Tool (RDT™ tester). When used together, samples can be taken from representative zones, and ICE Core sensors can be used to take readings throughout the well, yielding more data about fluid stratification. Samples are never better than when downhole. ICE Core technology provides a quick preview of results, a valuable backup, additional sampling points, and a reliable crosscheck. All of this reduces risk and uncertainty, while enabling field and financial planners to begin working immediately

Result 

After a sampling tool has exhausted its collection capacity, ICE Core™ technology can analyze additional zones downhole without the time and cost of an additional trip. Being able to collect fluid data from more zones without the extra cost and time of a second trip gives field planners valuable information about fluid stratification in the reservoir. 

After a sampling tool has exhausted its collection capacity, ICE Core™ technology can analyze additional zones downhole without the time and cost of an additional trip. Being able to collect fluid data from more zones without the extra cost and time of a second trip gives field planners valuable information about fluid stratification in the reservoir. 

The data that Statoil gathered in East Africa enabled them to begin planning budgets, platforms, tubulars, treatment facilities, and more – faster than ever before. By mitigating uncertainty and risk, the company was able to make decisions about the wells it tested with a higher degree of confidence. Statoil sees the value of ICE Core technology in accelerating the company’s E&P processes by compressing cycle time from discovery to production. Planning their next wells and production facilities can now happen much more quickly.