Log, running

One method of sampling reservoir fluids and taking formation pressures under reservoir conditions in open hole is by using a wireline formation tester. A number of wireline logging companies provide such a tool under the names such as RFT (repeat formation tester) and FMT (formation multi tester), so called because they can take a series of pressure samples in the same logging run. A newer version of the tool is called a modular dynamic tester or MDT (Schlumberger tool), shown in Figure 3.8. 

Hydrocarbon-water contact movement in the reservoir may be determined from the open hole logs of new wells drilled after the beginning of production, or from a thermal decay time (TDT) log run in an existing cased production well. The TDT is able to differentiate between hydrocarbons and saline water by measuring the thermal decay time of neutrons pulsed into the formation from a source in the tool. By running the TDT tool in the same well at intervals of say one or two years (time lapse TDTs), the rate of movement of the hydrocarbon-water contact can be tracked. This is useful in determining the displacement in the reservoir, as well as the encroachment of an aquifer. 

BHA — Change bottom hole assembly DMF — Down hole motor failure DSF — Drill string failure DST — Drill stem test DTF — Down hole tool failure LOG — Run logs CM — Condition mud CP — Core point DP — Drill plug FM — Formation change... 

Figure 4-289. Comparison of MWD ultrasonic caliper logs with the 4-arm wireline caliper logs run five days later. (Courtesy Anadrill [ 3].)...

Figure 4-294 shows a set of resistivity logs run in a sand-shale sequence of the Gulf Coast. We have one wireline dual induction log, one MWD resistivity log, a wiper-MWD resistivity log and one gamma ray log. 

Figure 4-294. Comparison of compensated dual-resistivity logs run while drilling and in a wiper pass with the wireline induction logs. (Courtesy Anadrill [113]. ...

Documentation, log A dated document detaihng what was done, by whom, and when. See also Log, calibration Log, maintenance Log, run time. 

Coring is performed in between drilling operations. Once the formation for which a core is required has been identified on the mud log, the drilling assembly is pulled out of hole. For coring operations a special assembly is run on drill pipe (Fig. 5.33) comprising a core bit and a core barrel. 

In stacked reservoirs, such as those found in deltaic series, it is common to find that some zones are not drained effectively. Through-casing logs such as thermal neutron and gamma ray spectroscopy devices can be run to investigate whether any layers with original oil saturations remain. Such zones can be perforated to increase oil production at the expense of wetter wells. 

Fig. 1. CPU times (in hours) for 1 ps MD runs for various proteins using three different methods, direct velocity Verlet with a time-step 0.5 fs, r-RESPA with direct evaluation of electrostatic forces and an overall time-step of 4.0 fs, and r-RESPA/TFMM with an overall time-step 4.0 fs (combination of (2,2,2,2) in force breakup).The energy conservation parameter log AE for the three methods are comparable. The CPU time (hours) is for RISC6000 /MODEL 590 computer.

You can obtain detailed results of ealeulation s by using Start I ig on th e File ni en u. The amount of calcu lational results is con trolled by the Qnan tn111PrintLcvel. The QnantuinPriiitLcvel can be changed In the CTIEM.IXI file before you run IlyperCheni or by a script command after you are running IlyperChem. For more detailsofthe log file and information saved in the log file, see the IlyperC hem Reference in an ual. 

The ah initio module can run HF, MP2 (single point), and CIS calculations. A number of common basis sets are included. Some results, such as population analysis, are only written to the log file. One test calculation failed to achieve SCF convergence, but no messages indicating that fact were given. Thus, it is advisable to examine the iteration energies in the log file. 

The significance of these numbers is seen as follows.The average values of A log t are to be added to the log t values at 126 or 130°C to superimpose the latter curves on the one measured at 128°C. Since these values are added to log t values, the effect is equivalent to multiplying the individual t values at 126 and 130°C by the appropriate antilogs to change the time scale in the individual runs to a common time scale. Using the case of 6 = 0.5 as an illustration, we see the following times are required to reach this level of crystallinity ... 

Satisfactory engine performance is assured by maintaining a minimum log that allows comparison of present characteristics with past records of (1) cylinder exhaust, cooling water, and supercharger exhaust temperature for similar loadings, (2) running sounds and smokiness of exhaust, and (3) engine efficiency and losses. 

The above information is conveniently summarised in the modulus diagram for a polymer. Figure 23.7 shows an example it is a modulus diagram for PMMA, and is typical of linear-amorphous polymers (PS, for example, has a very similar diagram). The modulus E is plotted, on a log scale, on the vertical axis it runs from 0.01 MPa to... 

Site D lacked a sufficient CRZ and also lacked access/egress control for the exclusion zone. The site control plan did not accurately identify the function of the CRZ as a buffer zone between the exclusion zone and the support zone, and there was no buffer area between the decontamination pad and the road that runs adjacent to the pad, marked as a support zone. Also, an exclusion zone log-in procedure for tracking personnel who enter and exit this zone was not used on site as called for in the SSAHP. 

Total Gamma Rays. Total gamma ray logs have been run on electric wireline since 1940. The sondes are rather small in diameter (1.5 to 4 in. or 37 to 100 mm). 

Four types of resistivity logs are currently run while drilling ... 

Figure 4-276. Comparison of the compensated dual-resistivity log resistivities run while drilling to the invaded and noninvaded resistivities calculated with wireline phasor induction data. The spurt loss is the ratio R /R (Courtesy Anadrill [tt3].)...

Figure 4-284 shows a typical MWD density log compared to a wireline density log. The calipers are also shown. At 1620 ft, the wireline caliper detects a much larger caving because it was run several days later. 

The Gulf Coast logs shown in Figure 4-287 have been run in the same interval with MWD/LWD sondes and wireline sondes. 

When the MWD systems are battery powered and have a downhole recording capability or use an electromagnetic telemetry, logging measurements can be repeated each time the bit is pulled out or run into the borehole. This new capability provides a way to map the progression of the filtrate front in the permeable formations. 

Porosity. Two porosity logs are run today (1994) namely, neutron and density. Soon the sonic will also be available. 

The overall performance will be monitored from the plant running log (see Chapter 33) and the heat exchange surfaces must be kept clean for maximum efficiency - meaning the lowest head pressure and lowest power. 

Advance warning should be had from the plant running log of any build-up of scale on water-cooled surfaces. Scale within the tubes of a straight double-pipe or shell-and-tube condenser can be mechanically removed with suitable wire brushes or high-pressure water lances, once the end covers have been removed. Tubes which cannot be dealt with in this way must be chemically cleaned (see also Chapter 33). 

Once this initial data has heen recorded, a running log will indicate the performance under service conditions. As the load and amhient conditions change, the plant operators will he ahle to monitor the day-to-day conditions. This estahlishes normal running. Only hy a clear understanding of what is normal can the abnormal be detected. 

---