Table Number 1
                                         How Rock Characteristics Affect a Show
ASSUMED HYDROCARBON TYPE - Sweet, high gravity, volatile Oil



ROCK CHARACTERISTIC           DRILLING MUD SHOW



I  POROSITY

   A. TYPE

      1. INTERGRANULAR        MODERATE   

         INTERCRYSTAL-

         LINE, OR

         INTERFRAGMENTA;

      2. VUGGY                MODERATE-LARGE  

      3. FRACTURED            LARGE

B. QUALITY

      1. HIGH                 LARGE

      2. LOW                  SMALL

II PERMEABILITY

   A. HIGH

      1. MATRIX               LARGE

      2. FRACTURE             LARGE

   B. LOW-DENSITY             VERY SMALL

III DRILLABILITY

   A. HIGH                    LARGE

   B. LOW                     SMALL

IV COMPOSITION

   A. CARBONACEOUS  SH        

      PETROLIFEROUS SH        LARGE

   B. COAL                    LARGE

   C. SALT                    NIL

   D. ANHYDRITE               NIL (USUALLY)


                                                            TABLE NUMBER 2
                            How Mud Characteristics Affect a Gas Detector Show
MUD    HYDROCARBON          MUD SHOW

       & ROCK TYPES



HI

       HI PERM. - GAS       LO    LIB. & NO PROD. GAS

D      HI PERM. - OIL       MOD.  LIB. & NO PROD. GAS

E      LO PERM. - GAS       NORM. LIB. & NO PROD. GAS

N      LO PERM. - OIL       NORM. LIB. & NO PROD. GAS

S

I      HI PERM. - GAS       NORMAL LIB.& PROB. PROD. GAS

T      HI PERM. - OIL       NORMAL LIB.& POSS. PROD. GAS

Y      LO PERM. - GAS       NORMAL LIB.& POSS. PROD. GAS

       LO PERM. - OIL       NORMAL LIB.& DBTFUL PROD. GAS

LO



HI



W      HI PERM. - GAS       V/LO    LIB.  N. EFFECT

A      HI PERM. - OIL       LO      LIB.  N. EFFECT

T      LO PERM. - GAS       MOD.LO  LIB.  N. EFFECT

E      LO PERM. - OIL       NORMAL  LIB.  N. EFFECT

R

       (assume small overbalance)

L

O      HI PERM. - GAS         NORMAL EFFECT

S      HI PERM. - OIL         NORMAL EFFECT

S      LO PERM. - GAS         NORMAL EFFECT

       LO PERM. - OIL         NORMAL EFFECT

LO



HI



V                             LOWER TRAP EFFICIENCY

I                             INCREASES RECYCLED GAS

S

C

O

S

I

T                             ENHANCES TRAP EFFICIENCY

Y                             MINIMIZES RECYCLED GAS



LO

                                                                   TABLE NUMBER 3

TABLE 10-8. Classification of limestones according to depositional texture

********************************************************************************************

                                                   *                   *Depositional texture

              Depositional texture recognizable    *                   *not recognizable

********************************************************************************************

                                                   *Original components* 

                                                   *bound together dur-*

Original components not bound during deposition    *ing deposition     *

****************************************************                   *

Contains mud(fine silt and            *Lacks       *                   *

             clay size particles)     *mud         *                   *

****************************************************                   *

       Mud-supported       *     Grain-supported   *                   * Crystalline carbonate

****************************************************                   * (subdivide according

Less than    *   More than *          *            *                   * to physical or dia-

10 percent   *   10 percent*          *            *                   * genetic texture)

grains       *   grains    *          *            *                   *

****************************          *            *                   *

Mudstone     *   Wackestone*Packstone * Grainstone * Boundstone        *  

*********************************************************************************************

Source: After Dunham (1962), Table 1. by permission Amer. Assoc. Petrol. Geol.




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