DOE Office Of Fossil Energy - Phillips Petroleum Company

Horizontal Injection Profile 6C-25H

Introduction

This is the first log on 6C-25H. Click here to see the results of the Injection Profile ran on CO2 Injection.

Recommendation

Cardinal Surveys Company chose the Madden System's Slicklogger, memory logging system, consisting of a continuous flow meter, quartz pressure sensor, external temperature, internal temperature, capacitance and gamma ray probe to be conveyed on BJ Services 1.25" coiled tubing. Memory logging systems offer the economic advantage of not requiring a dedicated coiled tubing / e-line unit and the Madden System has proven reliable in fields all over the world.

We had several factors to consider in maximizing the amount and quality of data acquired during the log:

500 bpd rate

500 barrels per day equates to only 10 feet per minute fluid velocity in the 100% flow region of the 6.125" open hole section.

2.313" X-Nipples

The significant reduction in hole size at the X-Nipples limits the size of flow meter used during logging.

Memory Tools

Because there is no surface readout of logging data, pre-job planning is imperative for a successful application of memory logging tools. A seasoned production logger's input is needed throughout the job design, job implementation, and processing of data. Only an experienced logger will have the knowledge base to predict possible down hole events and design a logging program to maximize results.

Horizontal Wellbore

Many reactions seen on logs ran in vertical wells will not always indicate the same cause in horizontal wells. Extreme care must be taken in analyzing data from a horizontal log so as not to confuse the results.

The combination of small I. D. clearance at the x-nipples and low injection rate was anticipated to hinder the flow meter's results. A 2.25" O. D. continuous flow meter would be the largest we could possibly run. This flow meter normally operates efficiently at rates of 500 barrels per day in 6.125" I. D. open hole. However, once we had logged past a major fluid loss, the flow meter would become ineffective. We also had to consider the probability of clogging a flow meter in a horizontal, open hole wellbore. We would not know the flow meter was clogged while running the log due to the memory system format.

It was decided that a modified, radioactive interface log would be run in conjunction with the memory system for additional data. Our calculations of displacements and rates showed that we could plan our logging passes around anticipated arrival times of the interface.

The continuous, mild solution of liquid ¹³¹I and injection water would be administered by Cardinal's patented Tagmaster System and monitored at surface with the Tagmaster Quality Control Log. The interface log would supply us with qualitative data concerning the loss of injected fluids in case we suffered a partial or complete flow meter failure. We would also gain quantitative data on the extent of fluid movement in the horizontal section.

Work Log

Dummy Run

A representative string of gauge and dummy bars were run in the hole on BJ's 1.25" O. D. coiled tubing to simulate the Madden Slicklogger Tool. We were unable to clear the x-nipple at 4933' MD with the dummy. The dummy was retrieved and re-configured to represent the smaller 1.6875" O. D. flow meter and run to 6892' WL with success. Note: This nearly assured an inconclusive flow meter survey and placed much more emphasis on the radioactive interface.

Radioactive Interface Tag

The Tagmaster started injecting a mild solution of ¹³¹I once the Slicklogger Tool had reached a depth of 2500' WL. This was calculated to allow time for a logging pass, ahead of the interface, across the entire horizontal section.

Logging Runs

All logging passes were run from 4800' WL to 6890' WL. We intentionally stopped 12 feet short of the dummy run as an additional safety factor.

First Logging Pass

Run down hole from 4800' WL to 6890' WL at 30 feet per minute. Our objectives, for this first logging pass, were to acquire a correlation gamma ray and injection temperature data.

Note: Some memory logging systems allow the operator to program each sensor to record at different times and thus run a logging procedure more like a conventional e-line job. However, it has been my experience that you can not acquire too much data. I prefer to record all sensors through out the entire logging procedure at a reasonable frequency. Record all your sensors and design each pass to enhance data acquisition for a particular sensor or group of sensors. For example, you want to log relatively slow for temperature, gamma ray, and pressure acquisition. Multiple passes at various speeds are required for flow meter data and stationary readings are preferred for several flow meter, temperature, and pressure applications. You never want to discard data just because it was not acquired at its optimum logging speed. I have personally experienced multiple occasions where the data from a memory logging tool conclusively showed holes in the tubing, non-functioning gas lift valves, and in one case, collapsed casing and leaking tubing in wells from the data acquired while running in the hole at over 150 feet per minute. Record all your sensors, all the time.

Second Logging Pass

Log up from 6880' WL to 4800' WL at 30 feet per minute. Our main objective on this pass was to get correlation gamma ray information for the up passes.

Third Logging Pass

Log down form 4800' WL to 6880' WL at 60 feet per minute. Main objectives were flow meter data and documenting the leading edge of the radioactive interface.

Stationary Readings At 6880' WL

Set stationary at 6880' WL for approximately 2 hours. This will allow the current injection rate of 487 barrels per day to displace the entire wellbore volume, plus 10 barrels. Gamma ray data could show the interface reaching the end of the wellbore and stationary pressure data could be of some use.

Shut Down Interface Tag

Switch the Tagmaster over to water and increase stroke frequency to clear all surface equipment of radioactive material. The Tagmaster Quality Control Log was monitored to assure surface clean up. The shut down time for the tag was calculated so that the tubing will be clear of all radioactive material prior to retrieving the logging tool.

Fourth Logging Pass

Log up from 6880' WL to 4800' WL at 60 feet per minute. Main objectives were flow meter data and documenting the leading edge of the radioactive interface.

Fifth Logging Pass

It should be understood that the original procedure called for a logging speed of 90 feet per minute to enhance flow meter performance. The speed was changed to 60 feet per minute due to safety concerns of BJ's coiled tubing operator. Our main objectives were flow meter and gamma ray interface data.

Sixth Logging Pass

Log up from 6880' WL to 4800' WL at 60 feet per minute. Our main objectives were flow meter and gamma ray interface data.

Shut-in Injection

Injection is shut-in with the tool string monitoring all sensors at 4800' WL. The main objective is to allow the wellbore temperature to decay back (warm up) towards its natural state so that a temperature pass can be made. Pressure data from the short fall off period can be valuable as well.

Seventh Logging Pass

Log down from 4800' WL to 6880' WL at 30 feet per minute after the well has been shut-in for one hour. The primary objective is to document areas of fluid storage. They will remain cooler than those that take no fluid. Notice that we make this pass at 30 feet per minute, just as we made the original injection temperature pass (Run #1). This speed optimizes temperature data acquisition and gives a basis for comparison to the injection temperature. It should be noted that the original procedure called for one hour and two hour shut-in passes. However, time constraints would only allow for one pass. Our secondary objective is to see the effects of the one hour shut-in on the radioactive interface.

Pull out of hole

Retrieve tools and coiled tubing from 6880' WL to surface. Water injection was also re-instated at this point to prevent any radio active material from returning to the surface.

Post Job - Radiation Survey

The wellhead, location, and all equipment was checked with a Micro-R meter for radioactive contamination. None was found.

Conclusions

Click here LOG PLOT 24k to see an example plot from data acquired in the Phillips Petroleum Company's South Cowden 6C-25H.

• Injecting and shut-in temperatures indicate fluid movement through the horizontal, open hole completion out to approximately 6600 feet MD with a major fluid loss at 5340 - 5480. They also indicate lesser fluid losses at 4940' - 4990' (near the casing shoe), 5185' - 5275', 5655' - 5695', 5775' - 5870', and 6210' - 6295'.

• Gamma ray passes and the fluid tagged with Cardinal's Tagmaster System also support these losses.

• The One Hour Shut-in Temperature and concurrent gamma ray pass (Run #7) indicate a crossflow from 6638' to 6295' while the well is shut-in. Also note the trailing edge of the tagged interface showing tubular cleanup.

• The 1.6875" flow meter did operate on several passes. However, the results were inconclusive as far as determining an injection profile.

• All temperature passes, Runs 1 - 7, (only runs 1 & 7 are presented on this web document) show a 1.5 degrees F cooling anomaly from 6650 to 6800. There is not enough wellbore deviation to substantiate this cooling. An influx of fluid coming from the formation into the end of the horizontal section appears to be the most plausible hypothesis. Unfortunately, we do not have any conclusive data from other sensors in this area of the wellbore to support this hypothesis like we did on the crossflow seen from 6638' to 6295' on Run #7. We can conclude that, if there is fluid influx, the rate is approximately the same whether the well is shut-in or on injection because the temperature remains constant under both conditions.

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