CASE STUDY Customized Solution Reduces Rig Time and Displaces Competitor MATURE FIELDS Lost Circulation Material Engineered Lost Circulation Treatments Overcome Total Losses in Heavily Faulted Area Location: North Texas Panhandle Region Overview For a competitor’s well in Ochiltree County, the 7-in. casing was set at MD 7,517 ft./TVD 6,981 ft. A 6-1/8-in. lateral was drilled with an 8.8 ppg dispersed water-based mud (WBM) to MD 8,833 ft./TVD 6,980 ft. where total lost circulation occurred. Initial LCM treatments included heavy concentrations of cedar fiber in the active system, two cedar fiber pills and a swelling polymer pill, which would not hold squeeze pressure. After waiting nine hours and rebuilding volume in the pits, the operator tripped to bottom but could not regain circulation. In Roberts County, Baroid provided drilling fluid services on a well in an area where an offset drilled by a different operator had lost 40,850 bbl in lateral section. After 7-in. casing was set at MD 9,573 ft./TVD 9,195 ft., the wellbore was displaced to 8.0 ppg INVERMUL® oil-based mud (OBM). As a contingency to limit potential OBM losses, the WBM system used to drill the upper hole was stored on location in frac tanks. At 9,620 ft. MD, total lost returns occurred, making it necessary to build and pump an engineered LCM pill. During the well planning phase, the operator asked the Baroid team to develop a reliable solution that would work in both water- and oil-based muds, to be used on wells serviced by Baroid or its competitors. Baroid recommended maintaining a well site inventory of DIAMOND SEAL® hydratable LCM, BAROLIFT® synthetic fiber, STOPPIT® composite material, and STEELSEAL® resilient graphitic carbon that could be quickly spotted in pill form when losses occurred. This solution was implemented on the Ochiltree County well and also on the Roberts County well where OBM was in use. For the Ochiltree County well, after the competitor failed to re-establish circulation by spotting cedar fiber and swelling polymer pills, the operator requested assistance from Baroid, per the well plan. Baroid personnel arrived with the LCM products and began preparing the pill. The operator laid down directional tools and tripped back to bottom. No displacement was seen while tripping and circulation could not be regained. CHALLENGE SOLUTION RESULT The operator was drilling horizontal wells in areas known for severe mud loss in the production interval. Attempts to remediate losses using conventional lost circulation material (LCM) had failed. Baroid built and pumped an engineered LCM pill for two wells. On one of the wells, Baroid replaced competitor for future work and saved six hours of rig time (estimated at USD 10,000) for the other well. Solving challenges.™ Baroid CASE STUDY: Customized Solution Reduces Rig Time and Displaces Competitor Baroid spotted an 80-bbl pill containing 100 ppb of STOPPIT®, 1.5 ppb BAROLIFT®, 2 ppb of cedar fiber, and 1.5 ppb of DIAMOND SEAL® LCM. The drillstring was pulled above the pill, the well was shut in, and mud was pumped down the backside to create squeeze pressure. In a four-hour period, 155 bbl was pumped without seeing returns. A second 80-bbl pill was spotted, this time with 100 ppb STOPPIT, 1.5 ppb BAROLIFT, 4 ppb cedar fiber, 3 ppb of DIAMOND SEAL and 5 ppb STEELSEAL® LCM. The pump pressure reached 1,000 psi but would not hold. A third 80-bbl pill was spotted immediately and the pump pressure increased to 1,450 psi. After repeating the squeeze procedure, the operator achieved partial returns. After the fourth pill, the pressure held steady, allowing the operator to pull out of the hole to pick up directional tools. At this time, the Baroid team suggested converting the active system to fresh water to minimize cost due to potential losses. High viscosity sweeps containing a lubricant would be used for hole cleaning. In addition, a quart of DIAMOND SEAL LCM should be poured into the drill pipe while making connections to help completely seal off the fault. No LCM was to be carried in the active fluid system. Following these recommendations, the operator resumed drilling the lateral with full returns. The well was drilled to the originally planned TD of 11,340 ft. with minimal seepage. At the Roberts County well, as recommended during planning, Baroid products including DIAMOND SEAL, BAROLIFT, STOPPIT, and STEELSEAL LCM were on location, along with the KCl/polymer WBM used to drill the upper hole. A 80-bbl pill containing 18 ppb STOPPIT LCM was spotted on bottom prior to laying down directional tools. The operator then tripped back to bottom and spotted a 40-bbl pill with 60 ppb STOPPIT LCM. Partial returns were observed while pumping this pill. Another pill containing 20 bbl of water, 1 ppb of BARAZAN® D viscosifier, 60 ppb of STOPPIT, 1 ppb DIAMOND SEAL, 1 ppb BAROLIFT, and 10 ppb STEELSEAL LCM was spotted immediately. Once it cleared the bit nearly full circulation was regained. The operator pulled the drillstring up to 1,000 ft. off bottom and began displacing the OBM to WBM. To save time, the Baroid team recommended letting the pump pressure from the displacement act as the squeeze on the pill. After displacing, the 10 ppb cedar fiber was added to the KCl/polymer WBM. After picking up directional tools and tripping back to bottom, the operator resumed drilling the lateral to TD at MD 13,670 ft./TVD 9,168 ft. with minimal losses. Before applying the engineered DIAMOND SEAL – STOPPIT LCM pills, the customer had exhausted existing options and would have plugged and abandoned the wellbore. The pills allowed a sufficient amount of production interval to be drilled and cased successfully so that the wells could be completed and produced as planned. On the Ochiltree County well, Baroid was awarded the rig after the production liner was installed, replacing the competitor service for future work. On the Roberts County well, the Baroid recommendation to use displacement pressure as the equivalent to holding squeeze pressure helped save 6 hours of rig time estimated at USD 10,000. www.halliburton.com Sales of Halliburton products and services will be in accord solely with the terms and conditions contained in the contract between Halliburton and the customer that is applicable to the sale. 02/2015 H011638 © 2015 Halliburton. All rights reserved.
© Copyright 2018