Repeat formation testing

The gradients may be caloulated from surface fluid densities, or may be directly measured by downhole pressure measurements using the repeat formation testing tool (RFT). The interfaces predicted can be used to confirm wireline measurements of fluid contact. 

Fig. 6. Retain capacity, (a) Leak off pressures and repeat formation test data from the North Sea Central Graben. The curve is the minimum in situ horizontal stress trend, determined from the lower bound of leak off test data, (b) Retain capacity in the North Sea Central Graben. Retain capacity is the difference between the minimum horizontal in situ stress and the fluid pressure at any point. At low retain capacity (1000 psi or lower) the likelihood of trap failure is increased (Gaarenstroom et al., 1993).

Pore pressure measurements have been compiled from drill stem tests (DST) and repeated formation tests (RFT) for the presumed reservoir zones in the study area. Since DST and RFT, are mn only in the reservoir zones, we have gathered information about fluid pore pressure through mud weight densities. The fluid pressures of investigated wells are summarized in Fig. 5. 

The data presented come from analysis of 351 petroleum fltxids from drill stem test (DST), repeat formation test (RFT) and production tests from basins in the North Sea, China, West Africa, USA and Germany. All data are quantitative measurements of the concentrations of various saturated and aromatic hydrocarbons in dead (separator degassed) oils and condensates from these petroleum systems. Concentrations are reported relative to the dead fluid, as would normally be the case. 

Using dilatometry in parallel with cyclic voltammetry (CV) measurements in lmolL 1 LiC104 EC-l,2-dimethoxy-ethane (DME), Besenhard et al. [87] found that over the voltage range of about 0.8-0.3 V (vs. Li/Li+), the HOPG crystal expands by up to 150 percent. Some of this expansion seems to be reversible, as up to 50 percent contraction due to partial deintercalation of solvated lithium cations was observed on the return step of the CV. It was concluded [87] that film formation occurs via chemical reduction of a solvated graphite intercalation compound (GIC) and that the permselective film (SEI) in fact penetrates into the bulk of the HOPG. It is important to repeat the tests conducted by Besenhard et al. [87] in other EC-based electrolytes in order to determine the severity of this phenomenon. 

K) Resin Formation. Place in a test tube 0.5 ml acetaldehyde and 3-4 ml of 6 iV sodium hydroxide solution. Shake and warm cautiously, noting the color of the mixture. Allow to stand. Repeat this test by using a very dilute solution of alkali. To 5 ml of water add one drop of 6 iV sodium hydroxide solution. This dilution gives roughly a solution of 0.1 per cent, while the concentrated solution is about 24 per cent. After shaking the mixture of alkali and aldehyde, warm and note the color. Finally boil the mixture and note cautiously the odor of the condensation product. 

Dake, L.P. 1982. Application of the repeat formation tester in vertical and horizontal pulse testing in the Middle Jurassic Brent Sands. Paper EUR 270, Proc. Eur. Offshore Pet. Conf. 1982. 

Analysed gases and oils are bottom-hole samples unless otherwise indicated in the text or figures. Bottom-hole samples (BHS) and cores generally predate enhanced oil recovery activity (1979-1984), thus represent original field conditions. Exceptions include multiple dynamic formation test (MDT) oils, repeat formation tester (RFT) oils, sidewall cores (SWC), or separator oil samples from recent wells usually at the periphery of the field. 

Formation pressure data were obtained from repeat formation tester (RFT) or modular dynamic tester (MDT) measurements of numerous deep wells in the Central North Sea. These data were used as the primary pressure dataset as they are the most accurate pressure measurements possible down-hole. The MDT/RFT wireline tool takes a pressure reading within a permeable formation, by setting a seal at a precise depth determined by using an accompanying gamma ray tool for depth correlation. Drill stem test (DST), mudweight data and kick (influxes of pore fluids into the wellbore) information was also used where RFT or MDT data were not available or of very poor quality. A summary of the various approaches used to derive formation pressures is provided by Holm (1998). 

Add 5 mL of the hydrochioric acid-zinc chloride reagent (Lucas reagent) to about 0.5 mL of the compound in a test tube. Stopper the tube and shake it allow the mixture to stand at room temperature. Try this test with known primary, secondary, and tertiary alcohols, and note the time required for the formation of an alkyl chloride, which appears either as a second layer or as an emulsion. Repeat the test with an unknown, and compare the result with the results from the knowns. 

THPC—Amide Process. The THPC—amide process is the first practical process based on THPC. It consists of a combination of THPC, TMM, and urea. In this process, there is the potential of polymer formation by THPC, melamine, and urea. There may also be some limited cross-linking between cellulose and the TMM system. The formulation also includes triethanolamine [102-71-6J, an acid scavenger, which slows polymerization at room temperature. Urea and triethanolamine react with the hydrochloric acid produced in the polymerization reaction, thus preventing acid damage to the fabric. This finish with suitable add-on passes the standard vertical flame test after repeated laundering (80). 

Methods of the first type have been used for both qualitative and quantitative investigation. An important limitation is that the rates of interconversion of the tautomeric forms must be small as compared with those of the test reaction (s). The method is further complicated since the test reactions are sometimes complex and it is difficult to be certain that only one tautomer is reacting. An even more fundamental objection is that much chemical evidence is based on incorrect reaction mechanisms. Thus, the formation of condensation products (30) with aldehydes has repeatedly been quoted as evidence for structures of type 31 and against type 32,. whereas if 31 does react with an aldehyde it must either first tautomerize to 32 or ionize to 33. 

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