Final Review

Question 1

name 4 of the 8 reasons for horizontal drilling

Answer 1

maximize reservoir exposure, maximize production, intersect natural fractures, SAGD, shale reservoirs (low permeability), gas storage schemes, EOR schemes (water flood), and thin pay zones

Question 2

why do horizontal wells cost more?

Answer 2

more casing, drill pipe wears faster, rig time, directional program (tools, DD, MWD, LWD) top drive rig, more cementing costs, and higher completion costs

Question 3

what bit is preferred for horizontal wells?

Answer 3

roller cones, although PDC’s are more practical (no bearing failure)

Question 4

what are the 4 areas of benefit using horizontal drilling

Answer 4

productivity: increase direct contact w/ reservoir, reduced pressure gradient at well bore, and more linear drainage along well bore
Development: reduced number of wells for max drainage, penetrates natural fractures
heterogeneous reserovirs: penetrate reservoir barriers that impede flow to the well bore
enhanced oil recovery projects: provide more contact for producers and injectors, increase sweep efficiency, etc

Question 5

why are horizontal wells beneficial in thin reservoirs?

Answer 5

the horizontal section does not have to be very long to exceed formation thickness

Question 6

know some of what info the well operator needs prior to planning the well

Answer 6

literally about 50 things to pick from

Question 7

know the roles of the drilling team and drilling engineer

Answer 7

Team: develop well trajectory & profile, well bore length, drilling fluids, casing requirements and program, and evaluation requirements.
Engineer: pick rig, design radius, pick bits,research offsets for borehole stability and prepare budgets

Question 8

what are the 3 types of well profiles

Answer 8

long, medium and short

Question 9

which profile requires the most space to reach 90degrees

Answer 9

long

Question 10

know some of the factors affecting choice of well profile

Answer 10

casing program, location of target entry point, surface location & ability to move it, distance between target entry & surface, minimum BUR restrictions, KOP restrictions, hole size & relationship to casing program, pay zone thickness, geological control, formation characteristics, lease restrictions, and completion techniques

Question 11

what profile does a SAGD well require?

Answer 11

Short

Question 12

be able to calculate the # of stations required to reach 90 given a BUR/30m

Answer 12

pretty straightforward, remember first angle is 0, not BUR angle

Question 13

what limits the length of the horizontal leg

Answer 13

torque, drag, WOB, hole size, and hole cleaning

Question 14

what is a multi lateral well?

Answer 14

multiple horizontal wells run through one mother well bore

Question 15

what are 3 reasons for multilateral wells?

Answer 15

stable or declining oil price, environmental concerns, and increasing costs

Question 16

what are 4 uses for multi lateral wells?

Answer 16

shallow or depleted reservoirs, layered reservoirs, fractured reservoirs, and steam soak. (wouldn’t hurt to be able to know how to draw all these)

Question 17

what are benefits of multi laterals

Answer 17

reduced well costs, higher production, less environmental impact, improved economics, increased recoverable reserves, additional fracture development, and heavy oil development

Question 18

know all 6 SPE classifications, & which 2 are the most common?

Answer 18

Level 3 & Level 6 are the most common

Question 19

what percentage of a companies Non Productive Time (NPT) does stuck pipe account for?

Answer 19

50%

Question 20

downhole problems can be classified 2 ways, what are they?

Answer 20

fluid related (poor hole cleaning, differential sticking, and lost circulation) or formation related (salt sections and sloughing shales)

Question 21

what are factors for preventing stuck pipe?

Answer 21

good planning, teamwork & communication, safe effective & standardized practises, understanding of downhole conditions, and recognition of early warning signs of stuck pipe

Question 22

what are the 4 key activities associated with stuck pipe?

Answer 22

selecting/changing the BHA, drilling, tripping, and running casing

Question 23

how do you prevent stkpp when selecting or changing the BHA

Answer 23

optimize JAR placement
accurately gauge worn bits & stabilizers
minimize total wall contact area (spiral collars)

Question 24

how do you prevent stkpp while drilling

Answer 24

use lessons learned from previous wells
record & monitor trends
ensure efficient hole cleaning (mud type & rheology, solids content, and flow rate)
regularly sweep with a Hi-Vis or Low-Vis pill
wipertrip
reream tight sections

Question 25

how do you prevent stkpp during tripping

Answer 25

prepare for the worst monitor circulating time & effectiveness of hole cleaning be prepared for issues (swab, excessive over pull)

Question 26

how do you prevent stkpp while running casing

Answer 26

only run casing when you know it'll reach bottom select proper run in speeds (minimize surge pressures) selection & number of centralizers (reduce drag) optimize mud rheology to suit running of casing & cement prepare response when encountering excessive drag and solids build up

Question 27

what are the 12 causes of stuck pipe?

Answer 27

differential sticking, geo pressurized formation, unconsolidated zone, key seating, reactive formation, drill string vibration, fractured/faulted formation, mobile formation, hole cleaning, borehole geometry, poor cement job, under gauge hole

Question 28

what are 2 early indicators of stuck pipe

Answer 28

increased torque and drag

Question 29

what is required in horizontal wells for effective hole cleaning?

Answer 29

higher annular velocity and higher viscosity mud

Question 30

what is minimum annular velocity determined by?

Answer 30

the cuttings slip velocity (the velocity the cuttings fall through mud)

Question 31

what is cuttings typical slip velocity?

Answer 31

15-18 meters/minute

Question 32

what is the assumption using stokes law?

Answer 32

perfectly spherical cutting, nu turbulent eddies formed behind particle.

Question 33

what equation should you never use to determine "f" or else Brendon will yell at you

Answer 33

equation 4, use Cd, sphericity, and Reynolds number on the chart to find "f"

Question 34

what are 6 of the 12 factors affecting cutting transport?

Answer 34

particle shape & size, fluid density, particle density, gravity, viscosity, borehole shape/quality, tubular sizes, inclination, fluid velocity, string rotation, ROP, and mud type

Question 35

understand how cutting accumulation in the well bore act at different inclinations

Answer 35

0-10: same as vertical, no buildup 10-30: will settle on low side of hole, form dunes that are picked and moved 30-60: most difficult, between 40-50 is most difficult to clean, cuttings accumulate & slide, can take up 25-30% of borehole diameter 60-90: settling doesn't get any worse closer to 90, particles don't slide because there already on bottom

Question 36

what problem can happen when the pumps are shut off between 40-50 degrees

Answer 36

cuttings slide down and can slide down annulus and block off the borehole (stuck pipe)

Question 37

what is the purpose of backing off?

Answer 37

to remove the string from the stuck portion of the BHA (fish)

Question 38

how does backing off work?

Answer 38

select back off point with 80% free pipe in tension & a minimum 80% free in torque, wireline will use a shot charge to loosen the threads, then back the string out of the fish.

Question 39

what are the 3 categories of fishing tools?

Answer 39

tools that destroy the fish, grab the outside of the fish, and grab the inside of the fish

Question 40

what are 8 kinds of fishing tools?

Answer 40

mills, overshot, junk basket, magnet, taper tap, washover shoe, spears, jars/bumper subs, junk sub, washover pipe

Question 41

what are the 3 types of fishing operations?

Answer 41

milling, displacement, and retrieval

Question 42

know how they all work, get other peoples prezies

Answer 42

and say please