Professional Fluid Services

While drilling ahead at 6,230’ total loss returns occurred. Five other cement plugs had been pumped without success. Over 2,500 bbls of drilling fluid had been lost.

The drill string was POOH to 8,400’ at the bottom of the Alamein formation and 7,900’ at the top. Attempts to circulate resulted in 30 bbls/hr losses. 1,000 bbls of volume lost over a 24-hour period.

All exposed sands were pay zones and the well was loosing 25 BPH.

The brown dolomite in the Texas panhandle area varies in depth and the degree of losses. The dolomite section can be more than 3500 ft. and losses can range from seepage to complete loss of returns. Operators use different types of LCM and concentrations to prevent losses while drilling vertical wells. When losses are large, the typical LCM is a combination of cottonseed hulls and very coarse fiber.

Directional wells require a different solution, as directional tools do not work well with the LCM used to seal the dolomite section. Noble Energy looked for a solution that would seal the dolomite section, reduce the LCM type and concentration to allow directional tools to work efficiently and not require cement or an added casing string.

The well hit depleted sandstone at 16,000’. Three other cement plugs were pumped prior to using Poly Plug® Ultra Squeeze and the wellbore was on vacuum.

A BP rig in El Paso drilled out a 13 3/8” casing shoe and could not obtain the desired shoe test.

The well lost complete returns at 16714’ and 1000 bbls of OBM was lost while attempting to circulate. Mud weight was cut and LCM pills were spotted in concentrations of 40-50 ppb, but another 700 bbls of OBM was still lost.