Well Integrity Technical Section

Hi Barkim,

There is a list of obvious requirements (price, dependability, support, data handling), but a quality I tend to prize is no wishful physics - you can call it no BS.

There is nothing wrong about proprietary algorithms and sonde details, but this is no reason for being cagey about the physics of measurement or just plainly striding into alternative realities. I'm being surrounded by segmented CBL giving USIT-like measurement, or the opposite: ultrasonic CBL. Flow behind casing companies postulate magic worlds of cement voids or microchannels (I fondly remember a marketing guy mansplaining these thermite-like tunnels to me).

They should say exactly what they measure and outline any processing done to the raw data. Then go on and discuss how the measurement responds to cement and its defects. No wild promises, no truth bending, no hand waving "ya know what I mean".

However this is not necessarily the service companies' fault. There are two attributes I recommend from operating companies before going out shopping for technology:

• Know your questions. What is it exactly that you want to know? What information and intelligence you need to drive action? Is it complying with regulation, or fixing a leak?
• Know how to turn data into information. The majority of petrophysicists hate cement logs, and don't understand them anyway. Anybody in your organization with cement and mechanical expertise? Some operators rely on wireline companies to provide data and interpretation. That's not necessarily wise: it's not their speciality and you generally don't pay them for the service (plus, it's a conflict of interest sometimes).

Best regards,

I had to laugh at myself.  When I first read the title of the topic, it reminded me of my time with Amoco and drilling exploration wells, particularly DW exploration wells.  The exploration department said we could use any logging company we wanted as long as it said Schlumberger on the side of the unit!

Do to bidding responsibilities on development and well repair wells, we would nearly always use a different WL company (typically Dresser).  I finally conceded that I would be given no choice on exploration wells so I used that "knowledge" to get a better deal!

I called in the GM for SLB in New Orleans and told him I would give him "all" the development work if they gave me a 15-20% discount on the exploration and stop calling deepwater remote work (which may only 50-75 miles offshore and still left from Fourchon).  He was skeptical and but talked to his bosses and came back and we made a deal.

Development wells went up maybe 10% (say $20k per well) but my "overall" wireline savings was well over $1 million a year.  This was 1992-3 with a million dollars was a lot of money!

The Asset Managers had to agree with my SLB deal but asked if the "savings" on the exploration wells could be applied to the development wells!  (The BU leader was an exploration guy and he told me not to worry about it--it was a savings for the company!)

Doug White

Sugar Land

When logging the casing or cement for well integrity, it's always a voodoo science.

From the early days of CBL (confusion bond log) to todays high tech tools for MFL's to USIT there will always be an element of doubt. And worse if you do find a problem, as a former drilling manager told me "son, we cannot remediate this cement annulus, why bother running the log?"

There is no real way to decide whose tool is better, the physics, calculation algorithms and assumptions are too vastly different. (the rubber band physics has been stretched to the limit)

On the very critical wells (big bore >300MMCFD wells), where the cementing was critical, we have run two different vendors on for each casing. Both vendors had good reputation for their tools but the physics on how the tools operated was radically different. That at least gave us two points of view.

On the lower cost wells, you really must trust your vendor logging analyst.
During the vendor selection process, you only see the salespeople and they will sell you the stars and moon.
Meet the actual log analyst and let them show you how they analyze the logs. Meet the SME's and field logging engineers as well.
Quiz them on what they see as limitations and problem they have seen in their logs.
If they act like car salesmen…….run.
If you trust their expertise, make sure you keep that crew for all your work consistently without changing them until the project is complete.

Its mostly about the experience and integrity of the person (executing job/analysis the log), more than the technology of the tool.

I had to laugh at myself.  When I first read the title of the topic, it reminded me of my time with Amoco and drilling exploration wells, particularly DW exploration wells.  The exploration department said we could use any logging company we wanted as long as it said Schlumberger on the side of the unit!

Do to bidding responsibilities on development and well repair wells, we would nearly always use a different WL company (typically Dresser).  I finally conceded that I would be given no choice on exploration wells so I used that "knowledge" to get a better deal!

I called in the GM for SLB in New Orleans and told him I would give him "all" the development work if they gave me a 15-20% discount on the exploration and stop calling deepwater remote work (which may only 50-75 miles offshore and still left from Fourchon).  He was skeptical and but talked to his bosses and came back and we made a deal.

Development wells went up maybe 10% (say $20k per well) but my "overall" wireline savings was well over $1 million a year.  This was 1992-3 with a million dollars was a lot of money!

The Asset Managers had to agree with my SLB deal but asked if the "savings" on the exploration wells could be applied to the development wells!  (The BU leader was an exploration guy and he told me not to worry about it--it was a savings for the company!)

Doug White

Sugar Land

One thing about the value of knowing cement distribution today relates to production string in long laterals.  Those regions with poor cement distribution will have poor isolation in multi stage, mult cluster PNP hydraulic fracture stimulation process.  So, with knowledge from logs of various types, decisions can be made on how to design the completions geometry in zones of dubious cement distribution or bonding.  That is one thing that CBL or other cement distribution logs can bring to modern well completions.  

When logging the casing or cement for well integrity, it's always a voodoo science.

From the early days of CBL (confusion bond log) to todays high tech tools for MFL's to USIT there will always be an element of doubt. And worse if you do find a problem, as a former drilling manager told me "son, we cannot remediate this cement annulus, why bother running the log?"

There is no real way to decide whose tool is better, the physics, calculation algorithms and assumptions are too vastly different. (the rubber band physics has been stretched to the limit)

On the very critical wells (big bore >300MMCFD wells), where the cementing was critical, we have run two different vendors on for each casing. Both vendors had good reputation for their tools but the physics on how the tools operated was radically different. That at least gave us two points of view.

On the lower cost wells, you really must trust your vendor logging analyst.
During the vendor selection process, you only see the salespeople and they will sell you the stars and moon.
Meet the actual log analyst and let them show you how they analyze the logs. Meet the SME's and field logging engineers as well.
Quiz them on what they see as limitations and problem they have seen in their logs.
If they act like car salesmen…….run.
If you trust their expertise, make sure you keep that crew for all your work consistently without changing them until the project is complete.

Its mostly about the experience and integrity of the person (executing job/analysis the log), more than the technology of the tool.

I had to laugh at myself.  When I first read the title of the topic, it reminded me of my time with Amoco and drilling exploration wells, particularly DW exploration wells.  The exploration department said we could use any logging company we wanted as long as it said Schlumberger on the side of the unit!

Do to bidding responsibilities on development and well repair wells, we would nearly always use a different WL company (typically Dresser).  I finally conceded that I would be given no choice on exploration wells so I used that "knowledge" to get a better deal!

I called in the GM for SLB in New Orleans and told him I would give him "all" the development work if they gave me a 15-20% discount on the exploration and stop calling deepwater remote work (which may only 50-75 miles offshore and still left from Fourchon).  He was skeptical and but talked to his bosses and came back and we made a deal.

Development wells went up maybe 10% (say $20k per well) but my "overall" wireline savings was well over $1 million a year.  This was 1992-3 with a million dollars was a lot of money!

The Asset Managers had to agree with my SLB deal but asked if the "savings" on the exploration wells could be applied to the development wells!  (The BU leader was an exploration guy and he told me not to worry about it--it was a savings for the company!)

Doug White

Sugar Land

IRP 13: Wireline Operations

An Industry Recommended Practice (IRP) for the Canadian Oil and Gas Industry