The Challenge:
Operator challange to regain circulation from 3,450 ft to 3,517 ft along serang marker formation (limestone). Possibly depletion within up fault block shallower reservoir due to prior production
The Action :
Pump 100 bbls STOPLOSS with 60 ppb concentration.
The Result :
Pump 100 bbls STOPLOSS with 60 ppb concentration.
The Challenge:
After finish run 13 3/8″ casing, Operator continue drill with 12 1/4″ section. The well has 240 bph dynamic loss and need to be cured.
The Action :
PJSM with comman and all the personel involve about job deployment. pump 20 bbls lead his vis follow pill# 1 with 180 bbls @16.5 ppb STOPLOSS,pill# 2 with 120 bbls @25 ppb, and pill# 3 with 120 bbls @ 25 ppb, pump 20 bbls tail hi vis pumping through by PBL. displace with 9.8 ppg WBM. Squeeze with 6.7 bbls, bleed of pressure and attemp to reverese circulation. Close and monitored well for one hour.
The Result :
SLoss rate decrease slowly until to zero. Operator continue drilling as program.
The Challenge :
Operator was difficult to pass through sui main limestone with directional BHA. Hole was complete losses. Switch to Foam (ECD 3.88 ppg) and drill down to target 2,029 m MD. Meanwhile losses were continued, gas influx was observed. LCM concentration through the annulus. Objective is to seal off the loss zone with plugging or any product which create barrier.
The Action :
After failure 7 times spotted and bullheaded 100 – 500 bbls with 60 – 200 ppb conventional LCM combination, no return. Operator approached other company to provide solution to control the losses. Contractor prepared specialized OBM Drilchem LCM with 40 ppb STOPLOSS, 30 ppb FRACSEAL and 20 CaCO3 F with respectly and supervise the operation. Bullheaded with 100 bbls STOPLOSS LCM pill of 90 ppb. followed by 40 bbls gel mud. After 3 hrs soaking time, pump 210 bbls 8.8 ppg gel mud to fill up the hole, 30 bbls squeeze.
The Result :
Hole was started to fill and succesfully return at surface were achieve, its pertinent to mention STOPLOSS hold about 1,261 psi above formation pressure.
The Challenge :
Wishing has a water sensitive shale in the 8½” section prone for mud losses, hole instability, and need to be drilled using oil based mud, resulted in a costly drilling operation. A highly deviated and horizontal sections in this field become even more difficult to drill.
The Action :
After the 9-5/8″ casing was set at 947,5 m, a horizontal 8½” hole was drilled. From 955 m the active mud was treated with FRACSEAL. Had smooth drilling and static hole until 1060 m, then a static loss (S/L) at 6 m3/hr (±38 bph) was observed. While maintaining FRACSEAL 6-8 ppb in the system drilling was continued penetrating further loss interval. At 1120 m had losses at 12 m3/hr (76 bph), 6 m3 (±38 bbl) STOPLOSS pill @ 37 ppb was pumped and followed by a hesitation squeeze. The incorporation of FRACSEAL in the active OBM was through direct additions or sweeping pills containing 15-20 ppb FRACSEAL.
The Result :
This section was drilled with minimized problems. Maintaining FRACSEAL in the active system gives tremendous effect to drilling efficiency. Hole remained relatively stable throughout horizontal drilling operation. It becomes product and treatment of choice for drilling the same section in this field, especially for high-angle and horizontal trajectory.
The Challenge :
Mud loss must be stopped before logging operation can be done in 8½” hole at 10,857 ft. Two different LCM pills were pumped but failed to stop or reduce loss rates to a satisfactory level.
The Action :
Drill bit was on bottom at 10,854 ft when partial losses observed. As other LCM pills did not provide acceptable result. Operator decided to use STOPLOSS regardless of unavailability of circulating sub on the string. The drill bit was a PDC with jet sizes of 6 x 18/32 nd”. Pumped 20 bbls Hi-Vis mud, 40 bbls of 45 ppb STOPLOSS then 10 bbls Hi – Vis tail spacer. Got partial returns. Hole was deepened to 10,857 ft and the second STOPLOSS pill was spotted on bottom and used stage up (progressive) pumping above pill for a hesitation squeeze with ECD. STOPLOSS was deployed thru bit jet nozzles.
The Result :
The STOPLOSS pill of 45 ppb was pumped through the PDC bit smoothly. The hole was static to carry out further operations. The whole STOPLOSS application process was conducted with the direct supervision of the operator. The job was successfully conducted by the Operator with no Drilchem engineer on the rig.
The Challenge :
To overcome losses in the Wonocolo formation. One of the most difficult carbonate / limestone loss zones to plug off. Some of experienced drilling personel believe that Wonocolo is incurable. Nothing can stop if losses occur in this formation.
The Action :
Starting from last casing at 1,769 5, despite of losses at >110 bph drilling from 1,790 ft, the 17½” hole was blind drilled to 3,189 ft (1,420 ft interval) using Seawater and Hivis sweeps. At 3,189 ft, (after passing through the Wonocolo formation) STOPLOSS pill of 777 bbls @ 45 ppb concentration was deployed in attempt to seal off the loss zone.
The Result :
After spotting STOPLOSS Static losses drastically reduced to 10 bph and then Zero. As static, the hole was then displaced to 9.8 KCL Lime Polymer mud and drilling operation was resumed without any problems.
The Challenge :
One of notorious loss areas in Indonesia, a troublesome carbonate/limestone section. Common problems are Severe losses and Hole Pack offs. In this interval, drill bits can easily encounter natural fractures and cavernous formations.
The Action :
Starting from last casing at 380 ft the 17½” hole was drilled using Seawater and Hivis sweeps. Drilling at 935 ft had sudden Dynamic loss at 423 BPH and then Total losses. Static losses observed was at 120 BPH. STOPLOSS pill was deployed by pumping in sequence 20 bbls lead Hi-Vis spacer, 50 bbls @45 ppb STOPLOSS pill and 20 bbls tail Hi-Vis spacer.
The Result :
After spotting STOPLOSS Static losses reduced to 10 BPH and then nil. Washed down to 935 ft and then hole was displaced to 9.0 KCL Polymer Mud. Drilling was resumed to target depth without any problems.
The Challenge :
The Vienna Basin has a history of lost circulation ranging from continuous seepage to severe losses. Complete losses, pack offs and stuck problems had caused lost of many BHA’s. The magnitude of overpressures in combination with the expected losses is the greatest challenge in planning this well. The 9⅝” casing cannot be set deeper than ± 3,600 m.
The Action :
The 12¼” hole was drilled from 2,954 m using a WBM (Glycol Polymer) of 1.57 SG. Severe losses were encountered up to 30 m3/hr. Active mud was pretreated with 5 ppb FRACSEAL. STOPLOSS pills were also deployed for controlling high losses. Through a circulating sub, pumped 2 m³ Hi Viscosity mud as lead spacer, followed by 6 m³ of 50 ppb STOPLOSS then 3 m³ of Hi Viscosity mud as tail spacer.
The Result :
Most losses were reduced by 90%. Shale stone (Gas Shale) was stabilised without any sloughing. The hole was drilled successfully without having to run the contingent 11¾” liner programmed to be set at 3,600 m. The cost saving for the elimination of this liner is approximately EUR 2.0 million (including the hole enlargement costs prior to running the liner). Drilling operation was performed successfully and the 9⅝” casing was run and cemented at 4,496 m, which considered to be one of the deepest 9⅝” casing point in Austria. The well was TD at 6,020 M using only 3 casing strings (previously had to use 4 or 5 casings). The final hole size (8 ½”) was drilled without having to reduce the mud weight.
