N.J. Admin. Code § 7:9D-2.10

Current through Register Vol. 56, No. 21, November 4, 2024

Section 7:9D-2.10 - Required procedures for sealing the annular space of any well

(a) The annular space within any well shall be sealed in accordance with one of the following methods:

1. For the pressure method, the grout shall be pumped through a tremie pipe installed into the annular space of the well in one continuous operation from the bottom to the top of the annular space unless the depth, resulting pressures, or subsurface conditions necessitate that the grout be installed in lifts;

i. The tremie pipe shall be slowly raised as the grout is being placed, keeping the discharge end of the pipe submerged in the grout at all times until the sealing of the annular space is completed;

ii. When pressure sealing the annular space directly above a filter or gravel pack, the grout shall be discharged from the tremie pipe so as not to disturb the top of the gravel pack;

2. For the inner string method, the grout shall be pumped through a tremie pipe and float shoe installed inside the casing of the well in one continuous operation so as to completely fill the annular space;

3. The displacement method shall be used only for wells in consolidated formations. A sufficient quantity of grout shall be pumped under pressure through a tremie pipe into the oversized borehole to ensure that the annular space will be completely filled with grout after the emplacement of a plugged casing into the borehole;

4. For the casing method (Halliburton Method), the grout shall be forced from the inside of the casing into the annular space utilizing a plug or a series of plugs. Grouting shall take place from the bottom up with the casing held in suspension; or

5. Sodium-based bentonite chips and shaped pellets may be installed in unconsolidated formations via gravity pouring to a maximum depth of 50 feet as follows:

i. All bentonite chips and shaped pellets shall be installed in accordance with manufacturer's specifications. To prevent bridging, all fine material shall be removed through screening or equivalent method, as specified by the manufacturer; and

ii. The grout material shall be placed from bottom to top until all annular space that is to be sealed is completely filled.

(b) For wells in unconsolidated formations, when the casing is driven into an undersized hole in accordance with N.J.A.C. 7:9D-2.2(a)8, the provision for sealing the annular space shall not be required.

(c) The following procedures shall be followed when sealing the annular space of any well:

1. All water used for the mixing of grout shall be of potable quality;

2. All pumpable grout slurry mixtures shall be weighed with a mud balance or otherwise verified by the well driller of the proper class so as to conform with the requirements in N.J.A.C. 7:9D-2.9;

3. The grout mixture shall be brought up to ground level to displace all water and materials in the annular space. Regrouting of a well is acceptable and shall be performed as follows:

i. Any settlement of the grout less than 50 feet from the ground surface shall be regrouted and completed by the pressure method or by using sodium-based bentonite chips and shaped pellets in accordance with (a)5 above;

ii. The driller shall return to the well no sooner than 24 hours nor later than 72 hours and fill all settling;

iii. Any settlement of 50 feet or greater shall be regrouted using the pressure method; and

iv. The finished level of the grout seal shall be at the level of the pitless well adapter or other connection; and

4. The grout being discharged from all annular space shall be weighed with a mud balance or otherwise verified by the well driller so as to comply with the requirements in 7:9D-2.9.

N.J. Admin. Code § 7:9D-2.10

Amended by 50 N.J.R. 171(a), effective 1/2/2018