True vertical depth

Fig. 14. Plot of LCAA ratios with depth (true vertical sub-sea) for Kuparuk River formation core extracts from selected wells 2E-17 heavily tar stained Kuparuk C4 central graben wells 2X-02 and 2Z-18 with good producing Kuparuk C and poor producing Kuparuk A and 3B-14 good producing well or downdip wells lJ-14 and lR-07 for different LCAA ratios (a) LCAAR-1, (b) LCAAR-2, (c) LCAAR-3 and (d) LCAAR-2. LCAA ratios are defined in the appendix.

Fig. 17. Plot of Rock-Eval 6 with depth (true vertical subsea) for Kuparuk River formation core extracts (a) for 2E-17. 2X-02, 2Z-18 and 3B-14 (see Fig. 14a—c) and (b) with higher density sampling showing gravity segregation-like trends for 2U-16 and 3H-09 wells.

In preparation for a field wide quick look correlation, all well logs need to be corrected for borehole inclination. This is done routinely with software which uses the measured depth below the derrick floor ( alonghole depth below derrick floor AHBDFor measured depth , MD) and the acquired directional surveys to calculate the true vertical depth subsea (TVSS). This is the vertical distance of a point below a common reference level, for instance chart datum (CD) or mean sea level (MSL). Figure 5.41 shows the relationship between the different depth measurements. 

Structural maps display the top (and sometimes the base) of the reservoir surface below the datum level. The depth values are always true vertical sub sea. One could say that the contours of structure maps provide a picture of the subsurface topography. They display the shape and extent of a hydrocarbon accumulation and indicate the dip and strike of the structure. The dip is defined as the angle of a plane with the horizontal, and Is perpendicular to the strike, which runs along the plane. 

Definition of Concepts. The hydrostatic pressure in a borehole is the pressure exerted by a column of fluid that height is the true vertical depth. This is... 

True vertical depth (TVD) The actual vertical depth of an inclined wellbore. Turhodrill A downhole motor that utilizes a turbine for power to rotate the bu. Turn A change in bearing of the hole usually spoken of as the right or left turn with the orientation that of an observer who views the well course from the surface site. 

F is expelled compaction driven flux (mVm per s), A0r is the porosity reduction during time T (s) and H is the true vertical thickness of rock column undergoing compaction (m). In the calculation of fluxes over the Melke-Gam Formation border we have assumed a subsidence rate of 2.0 x 10 km/year (sedimentation rate = 0.5 mm/year Fig. 2). The porosity of the Melke Formation at about 4 km depth is 3.0% (Table 3). The porosity loss due to compaction is es-... 

MD, measured depth TVD, true vertical depth Psa saturation pressure GLR, gas/liquid ratio TAN, total acid number. 

Hydrostatic pressure = density of drilling fluid x true vertical depth acceleration of gravity. If hydrostatic pressure is greater than or equal to formation pressure, formation fluid will not flow into the well-bore. 

An example of the log ran is a horizontal borehole as shown in Figure 4-271. The depths on the log are along the hole depths. Vertical depths are shown in the higher part of the log with a representation of the true radioactivity of each bed. The following observations can be made ... 

In summary, the need to provide software hooks at different parts and process points of an ELN system is of paramount importance to allow optimal integration with other systems. Companies are unlikely to adopt an ELN system designed as a monolithic application most certainly this is true for the larger pharmaceutical organizations. There is a still a place in the market for this kind of monolithic or vertically oriented application, but there is a consequent reduction in the broad applicability of the system, and the depth of benefits to be derived from its use. 

Most of the features of the theoretical treatment of bubble motion are present in the treatment that considers the water incompressible and neglects gravity effects. We quote from Cole (Ref 1, Chapt 8) The simplest approximation to the true motion of the bas bubble is the one in which it is assumed that the motion of the surrounding water is entirely radial and there is no vertical migration. In this approximation, which has been discussed by a number of writers, the hydrostatic buoyance resulting from differences in hydrostatic pressure at different depths is neglected. It is thus assumed that at an infinite distance from the bubble in any direction the pressure has the same value as the initial hydrostatic pressure P0 at the depth of the charge... 

Below a depth of around 1000 m, there is little variation in the concentration of DOC. This may be true as well for DON and DOP, but the increasingly irregular profiles at lower concentrations of DON and DOP preclude a definitive interpretation. Although concentrations of DOP are rather low in deep ocean waters (=0.02pmolkg 1), the irregularity in the vertical profiles of DON and DOP in Figure 11.2 is most likely attributable to the statistically small number of observations—only around two observations per depth interval between 2000 m and 5000 m. 

Our knowledge of the distribution of Pd in the water column is based on a study by Fee in 1983, the first to report a full vertical profile of any PGE in sea water. Vertical profiles of filtered and unfiltered samples from two different stations in the Pacific both show a systematic increase in concentration with increasing depth in the water column. The pattern of depth variation closely mimics that of Ni in the same samples. This similarity in the vertical distribution of these two metals and their similar upper crustal partition co-efficients (Figure 1) have been rationalized in terms of similar outer electron configuration. Both metals are believed to be stable in their divalent form in sea water. Subsequent more detailed study of the marine chemistry of Ni demonstrates that organic complexation plays an important role in Ni speciation, and laboratory experiments show the same can be true for Pd. Thus it seems likely that complexation by organic ligands plays an important role in Pd speciation in sea water. 

In true slides, the movement results from shear failure along one or several surfaces, such surfaces offering the least resistance to movement. The mass involved may or may not experience considerable deformation. One of the most common types of slide occurs in clay soils where the slip surface is approximately spoon-shaped. Such slides are referred to as rotational slides. They are commonly deep-seated (0.15 depth/length < 0.33). Although the slip surface is concave upwards, it seldom approximates to a circular arc of uniform curvature. For instance, if the shear strength of the soil is less in the horizontal than vertical direction, the arc may flatten out if the soil conditions are reversed, then the converse may apply. What is more, the shape of the slip surface is influenced by the discontinuity pattern of the materials involved (Bell and Maud, 1996). 

Note that we have divided the Darcy velocity by fractional porosity in the last step to have true velocity. The (8p/Bx) term was previously expressed in terms of (BT/Bx) and (Bxi/3x) (see Eq. (2.122)). Equation (2.139) applies to both thermal convection, where the convection is driven by (BT/Bx) as well as natural convection where flow is driven by (BT/Bx) and (BXi/Bx). As was stated before, convection may weaken or enhance composition variation. Figure 2.33 provides a simple explanation of the change in composition due to convection. In this figure, the diagram on the right (Fig. 2.33a) shows the composition variation vs. depth with zero convection at x = 0 assuming that = 0, and that and are not functions of temperature (see Eq. (2.125)). The thin line shows zero vertical compositional grading. Now allow for small values of pv (proportional to z) as shown by thick line B. Assume that pv is identically zero. Because of convection, the composition profile A cannot stay the same, otherwise the material balance for component 1... 

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