I dont see the big worry in going 15-20k hell even 100k oil change. As long as your having your oil checked via oil sample manufacture will let you know when to change. (Speaking on the half of amsoil) im reading a lot of well im comfortable with only changing at the longest of "x" miles.... take 30 seconds swab your stick put a 43cent or whatever stamps cost on it and wait for your graphs and information to come back... a warm and fuzzy isnt science... ill take science over gut feeling any day especially when the oil manufacture will warantee the motor. Go talk to your dealer if your under warantee both my vw's dealer had no problem honoring the warrantee as long as oil test samples were done every 10k or at the manufacture oil change intervals my 2012 golf tdi is at 32k miles and amsoil has been in it since 1000 miles..... amsoil if mobile 1 says its good for 15 im sure it is... oils and other synthetic fluids have come such a long way..
What what???? Swabs? That doesn't sound like it'd be even close to working. Pulling a sample off the dipstick isn't the same as from the (oil) suspension itself. I'm with others here, I thought all the labs wanted 3 ounces, (well at least 2+).
Oil analysis is an extremely valuable tool in a fleet environment where the engines have large crankcases, are operated for long idle times, driven for extended periods, over extended miles and used for heavy hauling. Also it is a great tool for manufacturers/dealerships if for no other reason than to CYA before having to pay for a new engine.
The objective purpose of regular analysis is to maximize equipment reliability by finding and realizing minor problems before they turn into major repairs. The only way that works however is by regular, frequent, monitoring and developing a history of what is happening inside the engine as it goes through the life cycle.
However there has to be an initial starting point and a trend established before a program can be used to monitor changes occurring within the engine. Using systematic intervals accounting for the lubricant time inside the engine, as well as the engine time (how long it has been in service) will need to be established and tracked. Taking ‘random’ samples provides nothing of use in the day to day operation of the engine.
The object is to monitor the engine for abnormal conditions and take action before those conditions lead to a catastrophic failure.
However for most all private owners (IE us) that drive cars as DD’s (daily drivers), doing regular maintenance, at scheduled oil change intervals, the value of testing may not validate the cost incurred. The theory is most, (not all) owners of passenger vehicles tend to drive them for less than 100,000 miles and get a new one. While engine failures of the oil related kind can occur within this range, it is highly unlikely as long as the oil has been changed with some sort of regular interval.
Furthermore, there are increasing numbers of manufacturers nowadays that warranty the engine for 100,000 miles anyway.

That being said, perhaps starting a monitoring program once the engine starts to approach the end of the warranty period would help not only to keep ahead of impending problems but also as a tool to keep the engine in service for years to come.
The cost of a typical analysis is what, $25.00 on average? Not draining the oil and only changing a filter plus adding a quart adds another $10.00~$15.00 to that cost.
How much is an oil change? Even with synthetic oil at over the counter prices (on sale) there are plenty of well respected brands available, with a very good filter and up to 6 quarts for $30.00~$35.00.
So at 10K you do an analysis, that’s $35.00~$40.00. Then at 20K another one, then say at 30K do a change. With the initial change at $35.00 and every analysis the same or more cost incurred then there is no cost savings whatsoever.
WITHOUT an already established trend of oil analysis in place it would be ludicrous to consider extended oil change periods. Using analysis to get away with, or try to justify extended oil changes in an engine where the cost of the analysis is equal to or greater than the oil change itself just doesn’t make sense as a value savings tool. Where regular analysis does save money is in high volume crankcases resulting in optimal run times of the lubicrant and substantial savings between changes. (Like in a 6.5 gallon crankcase the savings would be well over $100 if just skipping one change.)
My suggestion would be change the oil, change it regularly, and on schedule. Sending in a sample is a fine way to keep track of what is going on inside the engine. And something that everyone should do if they want to really know what is going on inside their engine.